Megaflo recharge of air gap

[@markchambers592]

Joe. You are an absolute legend. Countless plumbers called clueless to fix the drip. All pressure release valves changed pointlessly. And 13 min of your video and I've fixed it myself. Made all the noises you said it would. Makes complete sense now. If my mega flow had instructions they must be round the back and out of sight. Thank you so much for bothering to post this.

[@joewoodford9428]

@ Mark Chambers , Great to hear it was a success. If you would be kind enough to Like and if poss Sub, I would be grateful :)

[@mykel_616]

It's 5am and I was woken up by the sound of the overspill, thinking I had a major leak. Found your video after a quick Google search and now it's stopped. Been in my flat for 7 years, never know I needed to do that. Cheers fella!

[@joewoodford9428]

Really pleased it helped you out, please think to Like and Subscribe 👍

[@paulgerrard3]

Cheers for this.Just saved me £350 as my plumber said I needed 2 new valves and solenoid to cure constant dripping. Followed your video and hey presto ...fixed

[@joewoodford9428]

Your welcome, if it helped please think to Like and Sub as it helps me out withheld channel … Cheers Joe

[@stevesparkes165]

Helped me drain and refill my megaflo to get rid of a sulphur smell. Cheers!

[@garycarole891]

Hi, just a small note Joe, there is usually no need for the grips and clamp thing you did on the relief valve. When you turn the valve clockwise water will start to come out, if you continue to turn, the valve will return to seated, however there will be a point between those two where the wheel will sit on top of a cam and allow water to flow without any clamps. This point can be tricky to find, but not that hard !

[@joewoodford9428]

Good tip!

[@robertosoyaccino5638]

Gary - when you say ‘if you continue to turn the valve will return to seated’ do you mean it will click and automatically shut again? .... asking for a friend...

[@dontekillion7612]

Thanks a ton! This video just helped me to get my symphony system back up and running! 😀

[@joewoodford9428]

You're most welcome !

[@jkpirie]

Nice one Joe. I haven't been doing this correctly in the past, wasn't sure how long to wait for the gurgling to stop and I think I stopped too early in the past. After watching this detailed and well explained video I think I've cracked it. I have to use grips on that valve also, I think the Gary Carole below must have either a different valve or a worn one? There is just no way there is a useful Cam on my valve, it just goes straight from full open to snapped shut :) Anyway, the gurgling and water running from taps went on for about five minutes in my case as we have our cylinder on the ground floor. The plumbing was done when this house was a bungalo!

[@joewoodford9428]

Glad it helped you out !

[@paulsotheron710]

Very helpful. I found with our system when this requires doing is that we get no water from the hot taps.

[@joewoodford9428]

@ paul sotheron, worth doing every 12 months as per the manufactures recommendations

[@augustineamusan6586]

Thanks a lot Joe. The instructions we’re spot on and helped me to recharge my megaflow.

[@joewoodford9428]

@Augustine Amusan, you're most welcome and I'm happy it helped you out ! 😀

[@glenn1285]

For the closed unvented system, the 'open up lowest hot tap in house' relies on the siphon effect: water is 'sucked' out of the top of the tank (yes, up) and then down to the hot water tap . . . . . . when you haven't got an 'downstairs' (eg an apartment or the Megaflo is situated on the ground floor), this siphon effect is often not that powerful and 'stalls' (momentum of water is lost). You then think you have recharged the air-pocket . .. but you haven't. SO, the only way then is to drain some of the water from the bottom of the tank (the drain valve tap, usually via a hose to the shower tray if in an apartment, or have someone plumb it in to the tundish or into a waste pipe), leaving any hot water tap open where air will be sucked in. When you hear the bubbling stop (air being sucked in from the hot water tap through the water that is where the air gap should be) then you know the air gap is recharged. Then simply turn off the hot water tap, and turn the cold mains back on as shown in the video. Megaflo told me they are thinking about updating the instructions for this situation, which in apartments must be quite often.

[@glenn1285]

@@ziplockk I presume when you say "instructions shown here does not recharge the air volume correctly" you are referring to the video, not my comments?

[@timcarpenter2441]

When you say drain from the bottom of the tank, would the drain valve connected to the cold input that is at the lower side of the tank do? Thanks

[@abingdoncourt772]

@@timcarpenter2441 absolutley should be fine so long as there is nothing (like a check valve) inbetween that cold input drain valve and the tank. Don't forget to open a hot water tap and/or crack open the TPRV (anticlockwise) and hold it on the top of the cam. . . . . there is a skill to this without having to stand there for an hour or half an hour holding it, or, use a pair of molegrips/pliers and hold it open . . .to let in air towards the top of the tank to let the water fall out quicker at the bottom of the tank.

[@Ryan-jm9ch]

Thanks very much Joe. Just did ours and it seems to be ok. Our issue was water dripping from the overflow and the pressure sitting around 8 bar once the water was heating. Once we turned on the hot water tap the dripping stopped and pressure returned to around 3 bar. Hopefully these steps fix it

[@joewoodford9428]

HI Ryan, good luck hope it does. If this helped be sure to Like and if possible sub (its free and helps out the channels) Cheers Joe

[@Mit_yourfriend]

Should you continue to open the pressure valve until the gurgling stops?

[@joewoodford9428]

Yes, as the tank is still taking on air. But even after 30mins it will still be a lot than before. Hence my hack trick with the clamps as I can leave until it has stopped gurgling :)

[@FoodInDaHood]

Finally found the video I was looking for. Yes, very useful. Sub'd with bells. Thank you Joe.

[@joewoodford9428]

Awesome, thank you!

[@FoodInDaHood]

@@joewoodford9428. Hi. So I tried this yesterday and what a result. I now have proper pressure in my hot water system. Thank you again Joe.

[@caglaralkan2325]

Great video! I’ve moved into my new home for 3 years now and my hot water is hardly coming out of my two showers and taps. I’ve called out 2 plumbers neither could fix the issue. Im just concerned that i wont know what to do and don’t want to make any mistakes as you stated it can be dangerous.

[@joewoodford9428]

Do you get it fixed? Did the vid help you ?

[@caglaralkan2325]

@@joewoodford9428 unfortunately no i have not. I turned off the running supply but water was still coming out from taps, so i believe i may have turned off something different. I turned what ever i turned off Back on and left it to be. Still hot water is running low from all taps and showers at the flat. May need to call a megaflo engineer round.

[@mparthur144]

This is a common issue we have with electric hot water cylinders because of the green energy policies. No plumbers seem to know how to repair these cylinders apart from changing the elements/ time switch/ blending valve/ heat exchange pump to produce the hot water. If you have a British Gas home cover that includes plumbing, you could call them out to see if the lack of water is caused by a faulty blending valve. You need a G3 trained plumber for this job as not all ordinary plumbers are licenced to service the cylinder.

[@user-pk4sd9dd2w]

I'm still getting water dripping in tundish, despite replacing TPR valve and draining tank to restore air gap. Any advice? The tank is c. 16 years old. Could the internal air gap just be kaput and I need to install a separate expansion vessel? Thanks!

[@joewoodford9428]

Sounds like you need to speak with MegaFlo, they are now owned by Heatrae Sadia, give them a call as it should not be leaking if you have recharged the airgap. If you do find out please tell me as my tank is also +16yrs old

[@chohanchohan8208]

Excellent clear and precise video..Thank YOU so much

[@joewoodford9428]

@Chohan, you're welcome ! don't forget to Like and Subscribe

[@chohanchohan8208]

@@joewoodford9428 done brv..

[@philoshea3653]

Thanks for the video, really useful! Our megaflow is about 16 years old and I'm having to balance it about every 3 months which is a real chore. The TPR stays open on its own however when I closed it, by turning it anti-clockwise, I must've turned it too far because when I turned the cold water mains back on - it started gurgling like mad again - so then I had to put the TPR into a natural centre position to stop that. I'm surprised that with the technology available now one still has to manually balance these beasts.

[@joewoodford9428]

@ Phil O'Shea, glad it help a little. Sounds like you have the same issue I'm facing which needed to recharge it every couple of months. If it was helpful please give it a LIKE :)

[@grahamt19781]

27 year old megaflow here that needs recharging every couple of months. Thinking of having an external expansion vessel fitted???

[@joewoodford9428]

You need a qualified plumber to advise here. But at 27years a megaflo is your best solution!

[@PHarrington]

When recharging our 16 year old Sadia megaflo heatrae I followed the instructions but was unable to get a large amount of water to flow through the tundish. Could it be that the expansion capacity has been diminished badly. we have not long moved into our house and don't know if the previous owners carried out this procedure regularly. Might that be the answer for the flow from the hot tap Starts off fast but reduces to a much slower flow. Hope you can help.

[@joewoodford9428]

If you follow the process, make sure the cold feed to the megaflo is off, you should only have a small amount of water out the Tundish. To get full pressure you may need to leave the Tundish open for 30min or more. If its starts up fast then slows, the air bubble is not fully charged or the main water pressure to the tank is too low.

[@kevind7150]

The length of your D2 pipe looks less than 300mm before the first bend. Judging by the by the aluminium paint the cylinder was installed by the house builders?

[@joewoodford9428]

@Kevin D, the mains cold water feed to the Megflo Sandia's pressure reducing valve was fixed by a qualified plumber (see separate video on that I posted). As he was certified to work on a Megaflo I'm hoping it is installed to the UK codes. The silver paint was installed by the house builder and the house was built during 2002, so it would have followed the standards set out then. May I ask why you ask, do you have a concern? If so please share as others might be interested. Cheers Joe

[@kevind7150]

@@joewoodford9428 Hi Joe, Just an observation. I am a qualified heating professional. And I acquire a G3 licence. The licence permits me to work on, or carry out installs of unvented cylinders. up to 500litres, or 45kw Max input. I wasn't questioning who replaced your pressure reducing valve. The black 10bar temperature/pressure relief valve, tapped into the top side of your cylinder, has a 15mm copper pipe connected. This pipe is known as the D1 pipe (Discharge 1) Maximum length 600mm before the Tundish. The pipe after the Tundish known as the D2 pipe (Discharge 2) The length of this pipe should be a minimum of 300mm before the first bend. Silver paint is usually applied by house builders. To make the pipework more aesthetically pleasing. The paint as no thermal value. That's the giveaway, who installed the cylinder. This length of pipe is not to the building regulations, due to the closeness of the first bend. Discharged water could! back up and spill over the Tundish. This information can by found online. www.gov.uk/government/collections/approved-documents Under Approved Document G, G3, page 24. Hope this info helps?

[@tonycover949]

Many thanks Joe, it did the trick. Wish I had done this months ago 😀

[@joewoodford9428]

You're very welcome !!

[@carlwilson1772]

I have a megaflo and when I turn a hot tap on then off again, I get a loud vibration and juddering, like water hammer, coming from the tank pipework (hot water outlet pipe on the tank). If I open a tap lower in the system the noise stops, almost like dissipating pressure. Do you think this expansion air gap is the cause of this trouble? If not, what do you think is causing it?

[@chandarkie]

I have a cylinder service recently, and the plumber did the same thing and result in water hammer in the cylinder afterward, I realised that I can release some water from the cylinder valve every time I use toilet or tap to let the bang sound gone. I wonder if I should drain the hot water again myself to solve the issue ?

[@joewoodford9428]

@Darkie Chan, not sure the best fix, might be worth chatting to the plumber again. Water hammer is caused by high pressure being shut off too quickly. Closing a tap slowly usually manages this. I guessing you have great HW pressure now !!

[@eddieblackmore3188]

I enjoy watching your video so I decided to do it myself however the water supply valve to the tank will not move its stuck tight so I turned off the main water to the house and then turned on the hot tap unfortunately the hot water just keeps going any thoughts.

[@joewoodford9428]

Hi Eddie, if you have turned off the mains water supply into the house that is the same as shutting the valve from the balance flow. Does the house cold mains water stop when you have turned off the stop cock tape? It should as no mains pressure is coming into the house, so all your cold tapes should not run. If the megaflo tank is in a low position then there could be a lot of residual water in the pipes feeding it. It can take mine 10’s of mins to stop flowing, but the pressure should be very low as I have shown in the video and then a mere dribble at the end. Tell us how you get on!

[@elizabethowers6973]

If I have turned off the isolation (blue lever) and the water isn't stopping, what do I need to do?

[@joewoodford9428]

You then might need turn off the whole house supply. Usually the stop tape is under the main kitchen sink in a modern house. This should then shut off the cold feed completely to the house.

[@timcarpenter2441]

I have a ground floor MegaFlo. Is it possible to perform the hot tap drain by running a pipe from a downstairs tap to a lower level? Is it better to install a drain-off tap somewhere adjacent to the Megaflo? Is the only solution to repeatedly call out an engineer (which I prefer not to for obvious reasons)? Or? Thanks if anyone can advise.

[@joewoodford9428]

@@timcarpenter2441 hi, opening the hot water tap means the pressure behind the hot water is released. Down stairs is just what I do as it is the lowest tap, so drains pressured water from the tank and other hot taps in the house. To recharge I think you will be just fine using your sink hot tap. The only thing I can think is that as the blander expands it might have to work a little harder and might not fully recharge. But it should recharge the air gap.

[@timcarpenter2441]

@@joewoodford9428 Thanks - is there a risk the tank will drain too far? Airlock etc.? How would one know when to stop? Thanks

[@joewoodford9428]

@@timcarpenter2441 no issue with going too far, it balances with atmosphere, no more than that. To test if complete, I stick my finger over the tundish hole if it feels like it sucks when you release then leave it for another 10 to 20mins

[@remoone4593]

Any vids on how to de-pressurise the same boiler??

[@joewoodford9428]

@Remo one, not sure they make a boiler, our Megaflo is heated by an oil boiler, Thermecon. In the shot of the Red expansion tank this is where we pressurise the boiler for the CH. It should read no more than 1 bar. If less you need to top that up to 1 bar when boiler is off. That tank is feed by main cold water, there should be a small tap to allow water in. If not suggest looking at the boiler and seeing if there is a pressure gauge on it. Then google the boiler and read up on it. Good luck !

[@MultiTmanz]

When you open the hot water tap in the kitchen what will it do to the hot water in the mega floor? Is it empty the hot water in the mega floor?

[@joewoodford9428]

As the Megaflo is under pressure, the mains cold water pressure of 3Bar. By opening up the hot tap and closing off the cold water inlet to the tank you are releasing this pressure. By leaving the Hot Water tap open you allow the internal air cavity within the Megaflo to fill and balance with the atmosphere. Having the tap open helps you also tell when the tank has reached that point as well because no more water drips out. You will loose some of the heated hot water but it will not empty the whole tank ! Usual only a couple of sinks full. If that helped please Like and Sub to the channel ! Cheers Joe

[@Ryan-jm9ch]

Silly question but when I open the hot tap downstairs should I leave it running until it stops flowing completely or should I leave it running and open the value on the megaflo whilst it's running?

[@Ryo22]

I’m struggling to get anything flowing through the tundish after opening the prv. Once I open the valve, a small amount of dripping will go through the tundish then it stops after a couple minutes. The tank has continued gurgling for up to an hour and a half the last time I tried this, and I decided to just close the prv as it just didn’t seem to want to stop making that noise. Any ideas? Cheers Edit: just noticed the valve on my megaflo is completely different to yours. Mine is a light blue one and it doesn’t operate on a spring. I can literally open it up and leave it instead of having to hold it open

[@joewoodford9428]

@@Ryo22 hi, often only a little bit of water comes out into the tundish. Just want to check, you have isolated the mains cold water feed to the tank, and opened up a hot tap at a low point in the house before opening the tundish(as per my steps). Depending on how depleted the air gap is it could take 1hr. If water is dripping out of the tundish once closed and the water is on, then you need a plumber to check out the tundish as it might have some calcium build up. The tank should not gurgle once the air gap is balanced.

[@Ryo22]

@@joewoodford9428 yeah, I’ve closed the mains water supply before opening the tprv. I tried it again tonight and left it going for over an hour and a half but firstly the water never stopped dripping from the hot tap entirely and secondly the gurgling/bubbling sound from the tank did not stop either. In the end I had to close it. And yep, lo and behold, there’s still water dripping through the tundish. Think it’s best to get a professional out at this stage

[@joewoodford9428]

@@Ryo22 agree, probably just some calcium buildup preventing the tundish valve to fully shut. Are you in a very hard water area, and is the tank old? If so then a replacement valve might be your best option, cheaper than a new tank !!!

[@zabal_racing_33]

We have a megaflow 145L and we recently lost all water pressure, there is no hot water coming out any hot tap when we open them, could this process help? Or could it be a blocked pipe on the entry to the boiler?

[@joewoodford9428]

Could be many issues. Check the in flow to the megflo, also is there pressure in the tank. Try a recharge. Seek a plumber !

[@zenganow]

Great video. I have one of these tanks but started to make noise whenever I use the hot water? what do I need to do? change the ballcock valve (if it has one) or is to do with pressure.

[@joewoodford9428]

Hi Zenganow, as these are highly pressurised tanks probably best to get in a qualified plumber. If this process does not help then you need a specialist to check out the source of the issue.

[@andyh4066]

Hi Joe...I have done this but there is water still dripping in to the tundish.. what is usually the issue for this?

[@joewoodford9428]

Hi the tundish should stop dripping within a few hours. If this still happening it could be a bit a calcium build up (like grit). As the tank is now under pressure any gap in the seal means water could escape. This might be because the tundish had been leaking for a while. Your safest option is to get in a qualified plumber. I can make one other DIY suggestion but it could cause more problems. So suggest you get a professional in!

[@andyh4066]

@joewoodford9428 thanks for the reply...what would the one other DIY option be?

[@andyh4066]

@joewoodford9428 also...once I have turned the water supply off and open my hot tap...the water never actually stops, it just slows?

[@joewoodford9428]

DIY option is not recommended as it would involve changing the value. As this is a VERY high pressure system and that valve is a safety system I would not. If the tank is on the ground floor of the house I guess it might take ages for all the hot water to leave the system. I also open up one of the highest point hot taps to drain the hot water from all the pipes down to the kitchen. The key is to release as much pressure from the tank to allow it to equalise the pressure inside and out.

[@haroldmitchell5644]

Extremely clear presentation .Most useful.

[@joewoodford9428]

Hi Harold, you are most welcome :)

[@keshavlalbhudia9122]

Can you pressurise my megha flow tank

[@FoodInDaHood]

Quick question if I may. Some people recommend using a tyre inflator to add pressure to the Megaflo. What are your thoughts on this?

[@joewoodford9428]

@A P, Hi, thanks for the question. Everything I have read from the manufacturer and the instructions on the tank suggests to balance the air gap with atmospheric pressure. So there is not need (or way) to add additional pressure into the megaflo. The only tank that could required a bike/tyre pump to top it up is the central heating expansion tank, in my video that one is the red tank. I'm not qualified to tell you how to do this but this has nothing to do the megaflo and its air gap. If you have problems with that tank suggest getting in a plumber :) Good luck... thanks Joe

[@FoodInDaHood]

Hi Joe. Thank you very much for your reply. That makes sense now. Have a great weekend.

[@davidkneale7455]

Why would the age of the tank matter?

[@swiftrod2195]

Hi Joe, I have the same megaflow cylinder and it has been in place for the last 14 years. The air gap to my knowledge has never been re-established and i have reported water leaking from the tundish which is highly corroded with lime scale. The floor is now very damp so i have followed instructions on the label, did not see water flowing through tundish but was flowing through tap. Also when i turn the temperature release valve it does not have to be held and will stick. i held it for some 10 min or more and it was still gurgling and some water was still coming out of lowest hot water tap. In the end i just shut it off and turned mains back on and shut off tap once water was flowing freely. Any ideas?

[@joewoodford9428]

Hi Swiftrod, I'm not sure what your questions or issue is from what you have written in the comments. If the tank has never had the air gap replenished then it could take up to 30mins (or more) before it has achieved this. You can tell it has, by covering the tundish hole with your finger, if it sucks air in when you pull it away then it's still recharging. If you have a leak from the tundish then you need to get in a plumber as calcium has built up on the seal and will need to be sorted out. If this helped Like and Sub ! Thanks Joe

[@swiftrod2195]

@@joewoodford9428 Thanks Joe, will call a plumber!

[@MrAbdulHaque]

Thanks a lot. Just out of interest, what's the dimension of the cylinder and the dimension of the space that housed it? We're thinking of installing one under the stairs if it'll fit.

[@joewoodford9428]

I would check out the manufactures web site and get in a qualified plumber to assess the area. www.heatraesadia.com/products

[@jonbinnie]

Thank you! Great video!

[@joewoodford9428]

Glad you liked it!

[@MrTheomighty1]

My partner has got constant cold water running through the tundish why is this ?? Could a diy novice be able to sort it

[@joewoodford9428]

@ MrTheomighty1, have you tried the method I show in this video to recharge the air gap? If that's not working then you have fault on the PRV and I recommend you get in a plumber as this is a safety item for the tank. Good luck tell us how you get on?!

[@sreerajuk123]

I have an unvented hot water tank. The hot water pressure in low now and I have not recharged the system since we moved in 5 years ago. The tank itself I think is around 16 years old. Do you think recharging will help to increase the HW pressure. Thank you for your advice.

[@joewoodford9428]

@Suraj Krishnan, first a disclaimer 'm not a plumber, if you are worried to work on a Megaflo to recharge the air gap call one in. As mentioned this is a customer permitted activity, if the tank has not be recharged for 5 years and is 16yrs old it will have lost some of the air into the water in the tank. A recharge is a good first step to seeing if that solves your low pressure issue. If that does not fix the problem please contact a qualified plumber. Good luck and do tell us how you get on! Cheers Joe

[@AutoFreak10]

Thank you, this video was a great help

[@joewoodford9428]

You're welcome!

[@kuldipsinghdegon4572]

Thanks for the video. My mega flow tank is 18 years old and the hot water flow trickles down to zero after a few minutes. My cold water stopcock may be faulty.

[@joewoodford9428]

Also check the balance flow valve and circuit, there are some parts that could come away and block the flow.

[@giulianosolinas2725]

Hi Joe, I am a bit confused from the video, as it seems to be a discrepancy in what you do and say and what you write on the instructions. In the video you: 1 Close the main cold water supply 2 open the lowest hot tap in the house 3 hold open the pressure relief valve until all the gurgling noise stops and water stops running from hot tap 4 close the pressure relief valve and here start my confusion. You than say that you will close the hot tap downstairs (not shown in the video) but you open the main cold water supply instead. In the instruction, closing the hot tap should be the last step. So, my question is, at minute 8:46 before you open the main cold supply, should all the hot tap in the house be closed already? Hope my question is clear

[@joewoodford9428]

If you leave all the hot taps open when you open up the mains pressure they will expel the air in the system and also the mains pressurised hot water. And they kind of explode if you do this! So I would close all the hot taps and release the air in the system with care one tap at a time. You can leave also have lower hot tap slightly open if you like but do take care!

[@matthewmissons5167]

My pressure as indicated by two clocks, one near the megaflo system and one on the expansion vessel is below 1.0 bar now. Is this what I need to do boost it back up and will it go to far? Or do I need a plumber to come and fill the pressure by opening the filling loop? There is currently a label on the filling loop to the expansion vessel that says not to touch it. I can quite loudly hear radiators in upstairs rooms filling up now the pressure has dropped a bit. Your advice would be greatly appreciated, thank you!

[@matthewmissons5167]

The actual water pressure we have is really strong so I may sound stupid and it could be something else...

[@joewoodford9428]

@matthew Missons, First a disclaimer, I’m not a plumber and it is best if you are unsure to get one in. In the video you see for a few seconds a red expansion vessel just above the megaflo. This is for the heating system, on a close hot water system like the megaflo there are no header tanks in the loft. When you run the central heating the water in the CH system expands, to take up this expansion the system uses these expansion vessels, in the case of ours it is red but could be other colours. When the system is cold typically the gauge would read around 1bar. If the heating systems has lost some water then it will be lower than this. You can recharge these by topping them up, but it is advised to be no more than 1.5bar. The radiator noise might indicate you have air in the system, so bleed the radiators at the highest point or the ones making the noise. If there was a lot of air in the rad your gauge will now have dropped as the air is replaced by water held in the expansion vessel. Check and top up. If you are worried about any of this call in a plumber. This not an issue with the megaflo but with CH system.

[@zoe-t6w]

Hi I have a megaflo and cold water flow is fine for me however hot water pressure in shower has gradually become very low. Will replenishing the air gap improve this? It probably was last done about 6 months ago but pressure has dropped suddenly very recently. Thanks!

[@joewoodford9428]

@Zoe Parton, that is worrying! If you do a replenish again the air gap again, which I would recommend as the first step, did the tank fill quickly or very slowly. If slowly you might have a blockage between the Balance Valve and the second shut off value. I recently ran into that issue with our as there was a white plastic cap on one side of inner works of the Balance Value which came off blocking the main flow to the tank. This caused the water to run fast at first then very slowly. You need a plumber to fix this!

[@keshavlalbhudia9122]

Hi can you pressurise my megaflow tank Nw9 0dn

[@cricketemu4050]

thorough and useful - thanks

[@joewoodford9428]

Much appreciated!

[@Ryan-jm9ch]

I've found myself referring back to your video once again Joe. One silly question if I may... I turn the cold water supply off using the stopcock then turn on the hot water tap in the kitchen. Am I supposed to open the pressure release valve until both the gurgling from the tank stops and the hot water stops flowing completely before I close the pressure release valve? Thanks Joe. Subscribed

[@joewoodford9428]

Sorry for the delay, yes leave the stopcock closed until both the water running out of the hot tap has stopped and also the gurgling noise. Usually I leave these open for about 30mins. Close off the pressure value, then the hot tap and then turn on the cold. The tank should then pressurise from the main cold water. Now carefully let the air out of the hot taps (all of them) they will splutter !!! A towel is handy to have around then :) If this or the video helped please Like and Sub ... thanks

[@barrygill2213]

Great video Joe.....just a quick question I need to change my kitchen tape washer as it is dripping and getting worse do I have to do all this to stop water coming out the hot tap in kichen thanks

[@joewoodford9428]

Hi Barry, at the top of the HW tank is another leaver to shut off the hot water out flow from the tank. I would close that off and the Stop Cock on the house to be sure. I expect some water will come out of the hot tap but that is likely to just come from the water in the hot water system pipe work, if you want to be sure open up the lowest hot tap and then the highest hot tap. That will drain the water out, well most of it. Be sure to close them before you turn back on the water main feed and tank valve!!

[@barrygill2213]

@@joewoodford9428 thankyou joe I will be onit 👍👍

[@leecrumbie5147]

Hi Joe, thanks for a great video - this will give me the confidence to give this ago. Our tank is on the ground level - will the lack of gravity cause me problems? Hopefully will solve issues with noisy pipes and dripping showers. On another note, do you have any videos re: replacing a thermostat value on a radiator on a pressurised system?

[@joewoodford9428]

Hi Lee, I'm not a plumber just good at DIYer. If you want to change the whole radiator value, might be worth looking that up KZbin. A pressured heating system is no than different a normal CH system, you just have an expansion bottle instead of a loft tank. You will need to drain down the water out of the CH system, lower than the Rad you want change the value on. If up stairs you won't need to drain the whole system. If down stairs then you might have do the whole lot. The HW and CH are different systems. If worried get in plumber!!

[@jkpirie]

Hi Lee, I once managed to change my TRV's without draining the system b y just using a large towel and being very quick while swapping the valves :) I do recommend draining the system now though, I hadn't realised just how easy a job it was back then :) Also, my Magaflo is on the ground floor and it seemed to work ok although it was slow to recharge. I clamp[ed the valve open as in Joe's video and all went well. It did seem to take a while before the syphon effect started up though 👍

[@GilesCuckow]

Joe, I turned the dial on the main boiler to the left for a night then turned it back to the right after realising It's not to be messed with, the Tundis is now dripping slightly on the outside as if the tooth isn't working properly. Should I be worried my house is going to explode?

[@joewoodford9428]

@ Giles Cucko, sound like you need a plumber to check it out. If your boiler was producing HOT water at >90DegC the PRV will vents as the pressure and tank are too hot. Dripping sound lime you have damaged to seal due to it being too hot.

[@GilesCuckow]

​@@joewoodford9428 Thank you very much mate, appreciate you took the time to reply and give some advice, It's not leaking anymore for some reason, I don't understand. I'll think I'll have to take your advice and think about how I can get someone in to look at it for me, really tight on cash at the moment so it's either food or hot water for me! Subbed & will be checking out future content to see if I can learn something!

[@leightri]

how do you know when you need to do this?

[@joewoodford9428]

If you find there is low pressure in your hot taps. The supplier recommends to carry this out once per year. Older cylinders, like mine, need to be charge a couple of times per year. Thanks for the question, hope that helped, please think to Like the video and sub to channel ... Cheers Joe

[@robertosoyaccino5638]

Hi there - very helpful video - when I turned my T&P valve to open it, it ‘clicked’ and bounced back to closed? Is this a safety mechanism to stop it staying open?

[@joewoodford9428]

Yes the valve will slam close off if you turn it to far. This will not damage the valve if you do it a few times, but is you are in a hard water area some calcium might chip off causing the valve seal to not close off properly. Try and open the valve slowly a small amount, this is why I use the two clamps to hold it open just enough to let the air in. If this helped please think to like and Sub ;)

[@MrPrimetimeuk911]

Hi joe I’ve got the same system. My central heating is working but not hot water. When I press the hot water on the timer the boiler doesn’t react but does when I press the central heating button. Do you have any ideas.? Thank you jason

[@joewoodford9428]

@jason atkinson, My hot water and heating system is a Honeywell Smartfit set-up (16 years old), its rather odd as its a low voltage system so I probably can not give you much advice. I would probably start by looking at the on tank Thermostat (tank temperature gauge) to see if that is the issue as I believe most HW systems use this to see if the tank is hot enough first and if its too cold (

[@kenifchung]

I've holding the release value for half an hour it still makes the noise, water is still coming out. Is that normal?

[@joewoodford9428]

You can keep holding it open for longer if you like or use the technique I showed, after 30mins you probably have enough air, it can take up to 45mins to 1hr to complete. Really depends on the how low it got.

[@mdktf8681]

What is there is a drip still from overflow next to tank after I’ve done this?

[@joewoodford9428]

@M Dktf, is it dripping into the tundish from the value? If so you might have a bit of calcium grit. You could try closing the main tank inlet valve off (main water feed) and opening the value and quick closing it to see if that dislodges it (but do this with care as there is high pressure behind the valve now!!!) water will rush into the tundish. If it is still dripping get in a plumber and get them to change the valve.

[@rt1185]

Great video, thanks for posting 🙏 Just attempted this and found that the TPR on my Megaflo can remain open without holding it in place. If twisted again, it clicks back to the closed position as before. Is this an issue with the TPR as your video explained it needs to be held open (rather than staying open itself) until the gurgling stops? Thanks

[@joewoodford9428]

If it stays open and you can hear it gurgling that means air in going in to replenish the air gap. Leave it that way until it stops filling with air (about 30mins). BE SURE to close it before you switch the main water back onto the tank. If worried contact a qualified plumber. Cheers Joe [Please think to Like and Sub :) ]

[@bill500carphead]

What are the symptoms that let you know you need to do this,

[@joewoodford9428]

@bill500carphead, either low or very low HW pressure or you see dripping through teh Tundish.

[@bill500carphead]

@@joewoodford9428 I'm getting a vibration & rumbling sound, tundish isn't dripping & pressures same as always been. Going to check the pressure in the expansion vessel when the gauge I ordered turns up Thanks for the reply

[@joewoodford9428]

@@bill500carphead Rumbling doe snot sound good. I suggest you get in a plumber. Do try the to recharge the air gap, you never know, it might be the fix.

[@vshlesman]

thanks Joe. very informative and helpful! followed the instruction, but then I still get the 3-4 drops a second coming out from the overflow pipe. Is it safe to leave it like this for a while or I need to call an engineer asap

[@joewoodford9428]

Hi vshlesman, is there water dripping out from the TPVR into the tundish? If so then the TPRV will need to be replaced as its not making a good seal. If you live in a very hard water area this could be due to calcium/scum build up on the valve. Advice is replacing the value from a trusted supplier and get a Megaflo certified plumber to fit. There is also another possible source of water. If you recall in the video I show the red expansion tank, this takes up the CH pressure, there is also has a PRV on the top of this tank and the tank uses a diaphragm method to hold the pressure for the CH. Both the tank or that PRV could be the source of the problem. These expansion tanks can fail by filling up with water on both sides of the diaphragm. Typically the tank's PRV is connected to the same drain pipe as the TPRV/tundish leading out of the house.

[@davidkingston6318]

Hi Joe I recently had a plumber in who did this but opened up nearest cold tap not hot. Due to no gurgling he said that it cant be that and must be valve related...is this correct or should he have turned hot tap on. Also he only turned off cold water supply. Thanks

[@davidkingston6318]

Mine is a stelflow too

[@joewoodford9428]

Hi David, if you are looking to pressurise the hot water tank then you will need to release the hw pressure in the tank to allow the air gap to expand and take up the space. Opening a cold water tap will not do that. Please look at instruction picture I took, pause the video there and read through it. He should have the mains water feed to the tank off, either the whole house stop cock or the cold water feed on the tank usually the balance valve.

[@davidkingston6318]

Thanks Joe - he had the cold water feed to tank off which is downstairs and then opened up cold water tap not hot water tap before releasing pressure valve. Would this make a difference? Thanks

[@keithnewton8981]

I do not have a tondish just a very long pipe going through my wall that same connected to my hot water pipe and it has one of those plastic knob like the tank

[@joewoodford9428]

Sounds like you don’t have a properly installed Megaflo, they should have a Tundish installed so you can see if the tank is leaking. Maybe a plumber can comment !

[@grahammayling4857]

Same system for Tribune HE?

[@joewoodford9428]

Hi Graham no, this what Tribune HE says as it uses an External Expansion Vessel. So no internal air bubble. For Flexible and Reliable We have chosen to use an external expansion vessel for our Tribune HE. With no air bubble to lose, it promises improved reliability. Add flexible siting and reduced overall cylinder height and you have a winning combination.

[@grahammayling4857]

Thanks for your reply.Much appreciated.I have dripping in the tundush and the tap water is very very hot.Not something I can deal with myself.

[@joewoodford9428]

Hi Graham, I'm not a plumber so take this just as general advice. If the hot taps are V V hot then the TPRV is working as it should, as it will open up if the temperature gets close to 90degC or the pressure is getting too high. Does your boiler have a h/w temperature controller thermostat, if so this should be set to 60degC to a max 65degC.

[@Robbeddall]

my system says to open the 'nearest' tap.. not the lowest one. is this an important difference?

[@joewoodford9428]

Hi Robin, probably makes no difference. I have always just done the lowest tap. What you are looking for is as the air gap replenishes, the water from the tank discharge to allow for this expansion.

[@zyoungz100]

Yes make sure you open the highest tap int he house first ie bathroom hot tap then the lowest this will allow airflow through the cylinder and stop it getting a negative airlock you can split or warp the cylinder. Also to touch the prv this a safety device that does not always re seat

[@Matto216]

Hi Joe. This has been on my to do list for a while now but wasn't sure how to do it. My intention being to hopefully increase the hot water pressure. Is this a job you only need to do if you have dripping in the tundish? The system was installed in 2004 and we've been there just over 2 years. I doubt it was done by the previous owner.

[@joewoodford9428]

Hi Matt, this is suggested to be done once per year. If it has never been done then it should increase the pressure in your HW !

[@vjloudon17]

Great video and clear. How do I know which valves to turn to turn off the water? The mains tap to the house doesn't completely switch off the water so I don't feel confidante relying on that. Thank you

[@joewoodford9428]

@ vjloudon17, there should be a large 3Bar balance value close to the tank, I think show this in other videos so look that up. Shut that off as it the main feed to the tank as well. Have the mains tap off and the balance value off should do it. If you hear water rushing into the tank when you release the PVR then you have not shut off the mains water. Suggest getting in a plumber !

[@dct1]

Great guidance. Does this process affect the pressure gauge? Mines is situated above the tank. Currently reading below 1 bar.

[@joewoodford9428]

@Dan_Ecosse, is the gauge connected to the MegFlo or is it on a smaller expand vessel, mine is Red in the video. If it is on the smaller one that tank is used to take up the expression of the central heating system when it gets hot. If the gauge is around 1 bar your at the correct pressure. When I do this process on the MegFlo as the systems are not connected it has no effect on this gauge. Without seeing your full set-up I'm speculating. If you are worried about these steps please get in a plumber as these systems are complicated.

[@ianrowntree9726]

Hi Joe, I've got the same Mega Flo, the other day I ended up draining off all the hot water ( long story !) the hot water now only last for a short period of time, could it have anything to do with the air trap ? Many thanks.

[@joewoodford9428]

Hi Ian, Not sure how you can drain off all the HW as its mains pressure feed, it would usualy just run cool once the hot water has run too long? This sounds like something you need to speak to Scadia about. If you can replenish the air gap it might work, but what you describe is odd working behavior of the tank. Good luck, tell us how you get on!!

[@glenn1285]

The red tank you mentioned about 1.5 minutes in is red for a reason . .. . it is the expansion tank for your gas boiler . .nothing actually to do with the Megaflo itself. The expansion air pocket for unvented systems that that is situated out side the tank (yours is inside) is a white expansion vessel . . . . .Megaflo makes both types of air pockets tanks (internal air pocket and external air-pocket (internal and external to the hot water tank)). There are advantages and disadvantages of both.

[@joewoodford9428]

Hi Glen, thanks for all the comments. The system installed in my house is over 18 yrs old and as the builder never mentioned how to look after the tank and the air gap, hence the video. I know the Red Tank is for CH system to take up expansion of the heated water when that is on. I mentioned it as there is a PRV fitted to it and water can drip from this if that tank should fail. So you have two sources where water can be expelled outside the house. Your flat comments I'm sure will help others who do not have a lower HW tap to drain the water out of the tank. Cheers Joe

[@glenn1285]

Joe, you are in the small percentage of unvented cylinder owners who actually recharges the air-gap! Well done. Most don't and they have the system over pressured when the hot water heating is on, and hence dripping tundish . . . . For those with plastic push-fit fittings after the hot water, it puts a strain on them and often goes above the stated maximum pressure so they act as THE pressure relief valve and leak, instead of into the tundish via the designed and supplied pressure relief valve . . .or worse, pop and you then have flood on your hands. As for tenants in a block flats being asked to recharge their air-pockets in their unvented . .. .not a chance! . . . leading to so many unvented cylinders reliefing into the tundish or the the weak link else where, causing damp to grow over many months or years. I have a PowerPoint showing the Syphon Effect (your video) versus Bottom Drain method for recharging these unvented cylinders. Not sure How I would get that to you if you are interested. I have an unvented "Heat Store" system by Glendhill in another apartment (Heatrae Stadia do one as well). Mains pressure only so no chance of over-pressure. Maintenance: top up cold header tank every year or so due to evaporation (its a closed system) . . can be plumbed with a ball-cock to fill automatically provided there is a outlet to waste water or tundish, should the ball cock fail. I think I will be considering this system in the future in my current apartment which has a Magaflo, unvented, internal airpocket.

[@Xhooser]

@@glenn1285 Having a ground floor mounted Megaflo in need of a recharge, I would find your powerpoint on the bottom Drain method very useful Glenn. Any chance of a copy?

[@bigs-hl2zz]

Top vid saved me ££££ keep it up 👍

[@joewoodford9428]

Cool beans, please think to Like and Sub 👍😎

[@YoutubeHero666]

why do the house builder install these wrong and don't get picked up on in snagging!

[@mountsat]

What is the main reason to do recharge?

[@joewoodford9428]

The air gap looses a small amount into the tank and the hot water pressure reduces over time.

[@johnkelly2010]

Excellent thank you

[@joewoodford9428]

You are very welcome

[@seanhansford9642]

Great....Very helpful

[@joewoodford9428]

Glad it was helpful!

[@peterhort2981]

Should you switch the boiler off before doing this, or should the system be running?

[@joewoodford9428]

Hi Peter, you don't need to switch the boiler off, just turn off the HW and CH timer so the boiler does not fire during the process. I usually shut these off just before the family needs to use HW, so that the tank empties and fills with cold in normal use just before you carry out this process, so you don't waste too much 60degC water from the tank when you eventually open up the lowest hot tap as you top up the air gap. Not sure if it actually saves any money. But a great question! :)

[@peterhort2981]

@@joewoodford9428 Hi Joe, Many thanks for your speedy response; your instructions helped me to recharge the air gap. I also discovered that some builders working for us in the kitchen had blocked the overflow. But now the little brass air vent to the side of the cylinder is dripping. Do you have any advice?

[@joewoodford9428]

@Peter Hort, Long shot but it might just be some grit or calcium buildup effecting the valve. If the water can vent out of the house you could try opening it up and closing it quickly, that might wash it away. I'm assuming the valve you speaking about is the one with the tundish? If the problem persists you might need to replace the valve. I recommend using a plumber for this as it part of the tanks safety system. But as the valve is opened during the air gap recharge process and there is no pressure on this valve during this as the tank in and out flows are off it might be something considering if you are an expert DIYer.

[@zyoungz100]

Great video but you shouldn’t be using the prv this is a safety device that does not always re-seat . Secondly hot tap in the bathroom should always be open to stop air locking which can lead to the cylinder warping and leaking,

[@joewoodford9428]

I'm very sorry but you are wrong about the statement about the PRV. Megflo clearly states on the side of the Tank how this should be done by using the PRV. All of that instruction I copied verbatim down in the description text of the video and also show the label within the video [2mins 48Sec] to prevent uncertainty. I also have a plumber friend who is qualified to service Megaflo tanks and he says this is the only way to pressuriser the tank. You second suggestion is good advice about opening up a second tap. But do not forget to close it once the mains pressure is restored. All HW taps will splutter due to air in the systems for the first time they are used.

[@sebthered]

You're turning it to the right (clockwise) yet other videos for the same procedure are turning it to the left (anticlockwise) confusing.......?

[@joewoodford9428]

Not sure it matters, but turning this way has always worked for me over the 16yrs (x3 per year). I find turning it clockwise being right handed is more natural. If the vid helped, please LIKE. Thanks Joe

[@sebthered]

@@joewoodford9428 OK thanks for the clarification - my cylinder is sited in my garage can this procedure still be carried out?

[@joewoodford9428]

@@sebthered No reason not to unless its subzero as water might freeze but guess you are in the UK so should be fine.

[@cduffy4925]

Thanks 👍🏻

[@nitram419]

I *never* use pliers to hold open the relief valve knob of my MegaFlo! It's not designed for the force of pliers -- you could easily wreck it. Use your hands -- it's not hard.

[@joewoodford9428]

It's just a tip if you don't want to stay there for 20mins and get on with other stuff, as in the case of my tank it takes that long. The Mole grips are only loosely gripping the plastic valve cover so it is not damaging it.

[@elirocha8548]

I bought this water heater kzbin.infoUgkx8G49mV71sAzUl9shXyLW-r3XgHH9EVh1 for use in my bus conversion. I installed it under my kitchen sink and it is fed by a high efficiency on-demand LP water heater. It is both a backup hot water source as well as a water saving device since we have hot water on demand rather than having to wait for the gas on demand water heater to finish its ignition cycle. I decided on this water heater due to the fact that it only draws 1300watts when it's ON instead of the 1500 watts that most Water heaters this size draw. In an RV a couple hundred watts can be a big deal. With very low standby losses, I don't have to worry about excessive power consumption. When propane is not available for our gas water heater, in conjunction with our low flow shower head there is enough hot water available to shower, albeit we won't be taking "hotel showers." Also very happy with the recovery rate of this water heater. Granted, it is quite small, but it does exactly what we need it to do.

[@pauls826]

Are you a plumber?

[@joewoodford9428]

@Paul Smith , thanks for the question, not a plumber. I state 4mins 45sec in if you want to work on these systems they are dangerous and you need to get a certified plumber to work on them. This activity is OK and approved by Megaflo as a customer maintenance activity. I'm a physicist, engineer, electronic hobbyist and very competent DYIer. I have carried out this procedure now over 20 times.

[@pauls826]

Joe Woodford regardless weather your rocket scientist or not you shouldn’t be touching it you mentioned about changing the inlet/pressure reducing valve which you have to be G3 reg gas safe to do which I am you do know if anything goes wrong with them there like a bomb when they explode I’ve seen it happen

[@pauls826]

Joe Woodford there a lot of people in your comments changing valves there self a lot of them are not plumber/ heating engineers you posting videos are basically telling people it’s okay to change/maintain there cylinders I train every 5 years for this and it costs hundreds of pounds not to mention gas safe reg every year at £180 this is dangerous what your doing and you shouldn’t be showing people on KZbin because your board if somebody injures there self or kills someone because of your actions will you be able to sleep at night

[@joewoodford9428]

@Paul Smith, re-pressuring a MegaFlo is a End User/Customer activity and these instructions are from the Heatrae Sadia website. I show these instructions also printed on the side of the tank during the video and what I carry out are these steps. I also state , as I mentioned above, that any OTHER work should be carried out by a CERTIFIED plumber accredited to work on a MegaFlo. Here is the link on their website with the recommended steps to add air to the cylinder www.heatraesadia.com/information/frequently-asked-questions#Accordion9 This maintenance is required annually and requires no specialist skills or regulatory certificates to perform. Anything other work carried out on a Megaflo requires a plumber. If anyone feels they are uncomfortable to perform this process they should contact an accredited plumber. What I offer here is a visual guide to these instructions. Thanks for your comments.

[@pauls826]

You mentioned you changed the inlet valve are you a qualified plumber no therefore it’s illegal what you’ve done and people might think oh if he can do it I can if the hse saw this they would drag you through court also if the instructions are on the side of the tank why are you making videos to show people are you saying people can’t read your just a video junkoe

[@dinosaurusreximis1982]

You should be trained and accredited to work on Unvented Systems. Don't go changing parts, pay the money for a proper job.

[@joewoodford9428]

@daniel cogan, don't think I'm say anyone should replace parts on these, here I'm showing the manufactures recommendations on how to replenish the air gap, this customer approved task. Anyone who does not feel confident to do this has the option to call in a qualified plumber. Thanks for watching

[@dinosaurusreximis1982]

@@joewoodford9428 apologies, I thought you sold in your video that you'd replaced a part but on listening again I hear that you called in a plumber to replace. The video is well executed I have forwarded it to one of my customers and they now have hot water again.

[@joewoodford9428]

@@dinosaurusreximis1982 Thanks for the reply, no I would not endorse anyone who is NOT a qualified & certified closed h/w system plumber to work on a Megflo system. As you say they are under high pressure and if something goes wrong very dangerous. The air gap replenishment process is not dangerous if you follow the clear instructions on the tank. Hopefully anyone who watches this and reads these threads finds this informative and helpful. Cheers Joe

[@phillipbull3673]

D2 is wrong below the tundish lol

[@joewoodford9428]

@Phillip Bull, not sure I follow what you mean by D2 is wrong. This was how the Megflo was installed when I bought the house over 15yrs ago. It works OK so I'm not sure what is wrong?

[@phillipbull3673]

@@joewoodford9428 D2 is wrong after tundish ...300mm before first bend after tundish

[@joewoodford9428]

@@phillipbull3673 Oh, interesting must have been the original plumbers !! Does not effect the system, I guess if the PRV did dump water it might not flow out quickly enough?

[@phillipbull3673]

@@joewoodford9428 no doesn't effect system just doesn't meet regs

[@joewoodford9428]

phillip bull ah, nothing can be done now, system was installed over 15years ago. Thanks for the comments let’s hope it helps others 👍

[@yoya4766]

It could have been useful but instead was long winded, boring and droning. Also using clamps that aren't needed, over complicating things. Basically you say nothing simply, clearly or with impact. And why make dull pointless videos, especially as you tell everyone who comments, to get a plumber? I think we're grown up to know we can get a plumber!

[@joewoodford9428]

Dear Yo Ya, If you read other comments you will see a number of plumbers are very angry about the video as they say it should be carried out by a qualified person. I show, in a clear way, that this service can be carried out by the homeowner. It shows a trick I use rather then holding the valve open by hand, as it can take 30mins for my tank to balance. Also note the video has been on KZbin for many years and helped numerous people. If someone is worried about the process they should contact their local plumber, this is also to appease any plumbers who might watch this. Thank you for watching, Joe

[@andylees2940]

How do you know it is time to do this?

[@joewoodford9428]

Usually once per year or if the pressure is poor. As my tank is 20 years old we need to do this 4 times per year. Hope this helps.