How to drain down a central heating system - Combi boiler

[@edwardtout5064]

Hi Nick. I managed to move my radiator to another wall thanks to you. I was so scared to do it but after following your video carefully, I managed by myself. Roofer by trade but slowly getting the hang of plumbing. Legend mate, thank you for the brief and spot on video.

[@NickTaylorPlumbingLtd]

It's a pleasure! Thanks for the time to give me some positivity! love it! Keep up the plumbing and big up the Roofers! 😄

[@jackdavidson2115]

Awesome video! Straight to the point, allowed me to fix my radiators easily, Was nervous about going near the boiler but after watching this it made it so simple to drain and refill!

[@NickTaylorPlumbingLtd]

Hi Jack, thanks for your kind words and taking the time to write a nice comment. If you haven't already please like and subscribe to my page as it really helps.

[@alanvt1]

Drain the whole system?.... this headed with drain down boiler

[@TomBartram-b1c]

If the water upstairs tees down into two unconnected sides then how does the it circulate?

[@philipduckworth3062]

Cheers for that no frills straight to the point no giggles. Spoken like your talking to another willing DIY adult. Thank-you. You made it look so simple

[@lapisarafa6963]

You've been a massive help, very informative. I had to install new TRVs and had no clue it was this easy to drain down a system

[@davidholloway1776]

Thanks very much for this Nick. Drained down, changed two TRVs, and refilled without any issues. Much obliged to you for taking the time to post this.

[@robbyde2]

You have saved my ceilings from being flooded. Thank you

[@albyrobinsonisthebestatfoo3002]

Great video that. More straightforward than others ive watched. Thanks

[@megascrim750]

Nick i cant thank you enough for this easy straight forward video. I did everthing you said and i had no issues. Keep rockn nick.🤘👋

[@descendantofgoku5548]

Very well explained mate, quality instruction. Thank you

[@danielladillon2360]

Great video easy to follow. Saved me £600 so very happy 💃🏾💃🏾💃🏾💃🏾💃🏾 and I’m warm 😀

[@EmmHotch]

Thanks so much for this! Moved my radiator with no problems at all. 👏👏

[@NickTaylorPlumbingLtd]

Hi Emma. Great to hear well done you! ❤️🙌

[@KdeB]

A great and simply explained video Nick. I'm a Trader so not much to do with plumbing, but you teach well and I was quite successful changing the rad! Cheers man

[@johnlangrish7691]

Thanks Nick your video was clear, concise, extremely informative and a pleasure to watch. I wish that are utube DIY manuals were as good as yours!

[@eddyjawed4871]

I love your explanation so much better than the others

[@NickTaylorPlumbingLtd]

Hi Eddy, thanks for your message and its always nice to have positive feedback. Any questions or any video requests please feel free to ask. If you haven't already don't forget to like and subscribe.

[@stephenburns3262]

Nice job and video and explanation for the residential tech .

[@NickTaylorPlumbingLtd]

Glad you liked it!

[@wonderworld4056]

Many thanks for your instructive and simple explanation, that was good tutorial

[@steves1460]

Good, clear video. Probs worth mentioning the converse scenario of not needing to drain a whole system, if the part you are working on has been drained e.g. no need to drain downstairs, if working on a rad upstairs.

[@NickTaylorPlumbingLtd]

Hi Steve, Its a good point, however Id rather show how to empty the whole system to prevent any accidents happening for our viewers, we've all been there ;)

[@luongtime5364]

Straight to the point, thanks Nick

[@robevs100ok]

best vid iv seen straight to the point

[@deanbadhamswilliams2047]

Best video iv seen explained bang on ..thanks

[@tonymoon4525]

Thank you for an excellent tutorial. I will try it out tomorrow.

[@martinturner5067]

Good explanation Nick on drain down and refilling the c/h pipe work system. However, in your process you’ve not put any inhibitor back into the pipe work when filling? How would you do that when filling back? Thanks

[@asadansari7897]

Thanks 😊 Nick very useful video, I feel confident do a little job tomorrow. AA Slough Berkshire.

[@NickTaylorPlumbingLtd]

Hi Asad, thanks for your message, that's great news how did you get on?

[@andyr4611]

Thanks for the clear instructions Nick as I need to do this, I am wondering at what point should chemicals bs added to the system as I live in a very hard water area? Thanks again.

[@robbaker5080]

Really clear video. One question though, for those of us on single-level flats/apartments i.e. when the boiler is the highest point in the system: how do you let air into the system when draining? Is there a risk of damaging the boiler by pulling a vacuum if you drain it without opening any bleeds? My towel rail is the highest bleed, but it still floods water everywhere because it's a foot below my boiler!

[@rayc1503]

If your boiler's at the highest point of the system there's absolutely no need to drain the boiler.

[@markrayton6385]

Excellent video. Very well explained. Thank you very much for sharing.

[@NickTaylorPlumbingLtd]

Hi Mark, thanks for your kind words and taking the time to write a nice comment. If you haven't already please like and subscribe to my page as it really helps.

[@mrmiah7184]

Good explanation 👍🏼

[@NickTaylorPlumbingLtd]

Glad you liked it!

[@andreikaportsev6684]

Thank you for the video. Good explanation re. multiple drain cocks in the house. Very helpful.

[@NickTaylorPlumbingLtd]

Hi Andrei, Thanks for your kind words! Keep up the plumbing and if you haven't already don't forget to subscribe for more helpful info.

[@andreikaportsev6684]

@@NickTaylorPlumbingLtd Successfully flushed, cleaned and refilled my CH system last weekend! Added some inhibitor too, should be good for now. There were three drain cocks to deal with and one of them was leaking, so I replaced it too. That and the filling loop valve which was not shutting properly, so pressure was building up and leaking water via the PRV. Feeling great about doing it all by myself! :)

[@NickTaylorPlumbingLtd]

Andrei Kaportsev great to hear keep up the good work! 👍

[@raj080288]

Well explained. So if i have 3 floors, would i have to bleed both, the second and third floor rads or just second floor? My drain valve is on the ground floor

[@garyriley9116]

Great video, easy to follow thank you 👍🏻👍🏻

[@ajv8131]

Great video Nick. Very informative!

[@NickTaylorPlumbingLtd]

Hi AJ, Wonderful thanks for your kind words and hope it helped, Ill be putting up plenty of videos so if you haven't already don't forget to like and subscribe. Thanks again, Nick

[@simonperry5990]

Good vid, Cheers Nick!

[@CFreeJ]

Excellent video!

[@UnstoppableTramp]

Thank you for this video mate 💪

[@nosycatUK]

Thank you

[@NickTaylorPlumbingLtd]

❤

[@lukasz070485]

Great explanation mate!!

[@NickTaylorPlumbingLtd]

Hi Lukasz, Thanks for the comment always nice to have positive feedback. If you haven't already don't forget to like and subscribe.

[@Bzz22]

Hi is it possible to close down all the rads except the rad being worked on & just drain from that rad , saving time emptying part of the system & refilling .

[@rayc1503]

Yes, just make sure tge boiler stays switched off for the duration and all valves are gill shut. If you have a tank on an f&e system then you have to isolate and create an airlock.

[@MrBailsUK]

Great video, I have a glow worm Ultimate 30c combi boiler, but need to remove 2 radiators so I can plaster the walls. Can i still use my hot water for showers and such(radiators will be removed for a week or so), or would i need to isolate something first? Dave

[@lesliejenkins3788]

very enlightening made it look easy thanks to the plumber

[@PH493]

Good video, do you need to purge the boiler as well after filling?

[@NickTaylorPlumbingLtd]

You should not need too, your boiler should remove the air itself of push it via the pump to the highest radiator on the system, hope that helps 👍

[@Drifter077]

Mine are bit old radiator and don't have them drain valves.. but can you use on to drain out top floor radiators on boiler?? They should have drain valve should they?? Thanks for educative video

[@migry]

I have a leaking 90degree plastic elbow in the ceiling immediately beneath my combi boiler. Found due to staining of ceiling. Strangely system had been good for 8 years, and the leak only appeared after the boiler was serviced. I wonder if the heating water temperature setting was higher after the service and just enough to cause the leak? I saw the service engineer "waggle" the temperate dials which I think is part of putting the boiler into service mode. I have no idea of the original temperature setting, but I never changed it in all those years. Currently it drips. If I refill the system it is good for a few hours until the pressure drops and the boiler shuts itself down. According to a friend I should find a drain point on one of the ground floor radiators (he says it a legal requirement) but there isn't any drain point on any radiator. According to the same friend he suggested for him it would be a DIY job. He lives too far away to help 😞 He also suggested that freezer spray could be used to isolate the pipes around the elbow, although on the upper side of the elbow is the pipe that comes straight from the boiler and I assume(!) that there is an isolation valve on the output of the heating feed which will take care of that side of the elbow? I have used Checkatrade to find interested parties. I emailed one company all details (including lack of drain point). They have said that the job will take 2 to 3 hours. Since in my layman's head swapping the elbow should be pretty quick, what is it about the job that means it could take 2 possibly 3 hours? I just want to make sure that I'm not being taken for a ride.

[@atommachine]

Great thanks, I have a rad to add and need to cut into the 22mm so i can do this now as i was worried about air getting into the boiler :)

[@NickTaylorPlumbingLtd]

Hi Atommachine, thanks for your message, any type of draining the system will create air in your system, infact all system create air inside themselves as the water rusts the inside of the radiators and that process releases air. If you have any difficulties with an airlock, check out my other videos which explain how to remove an airlock. Hope that helps. If you haven't already don't forget to like and subscribe.

[@gerryquinn5224]

...and don't forget also to put some jollup in the system while or before you fill the system. One of the Fernox type products (X100 or similar).

[@smarte.r.1450]

Thank you very much for making this video

[@mattfay44able]

Great video but why do you need to drain the whole system if its a combi boiler? Whenever I change a radiator valve on a combi system i always drop the pressure down with the pressure release valve and isolate the flow pipe valve. I get about half a litre of water coming out the pipes when i undo the rad valves but thats it. Change the rad valves, open the flow valve back up, re-pressurise the boiler, bleed the radiator and job done.

[@NickTaylorPlumbingLtd]

Hi M F, thanks for your kind words and taking the time to write a nice and informative comment, although I would say you're a braver man than I am. If you haven't already please like and subscribe to my page as it really helps.

[@shadalak]

Ahh man you are a star. Do you think that draining my system would be a good idea if I'm getting gurgling/bubbling noises from my boiler? Sounds like theres an air bubble in there.

[@pacy4]

Thanks for the video.

[@werdna21]

Thanks for the video, do you have to add some form of cleaning solution to the central Heating system when draining and filling back Up again?

[@LBUK.]

Yes ideally

[@eduardmitu5967]

Very well explained, top man!

[@Spicymuffin]

Hi, great video and thank you. Is it safe to dump glycols/biocide/molybdate etc straight out onto the ground? Wont this leach into the surrounding soils and eventually into the water course?

[@JamSmi]

Yes it will, ideally draining into a sewer waste is better otherwise you're just contaminating the ground

[@pistopit7142]

Amazing video, you have a new subscriber Sir. I do not have drain valve anywhere in a system. All there is, is just valves with TRVs and valves for rebalncing the system. Can I just unscrew one of these valves entirelly from the radiator and drain the system that way? If so does it matter which radiator I use for draining the water? I have 5 radiators in a system all on the same floor. Water is basically black when I am bleeding radiators so I need to get rid of that water and get new fresh water into the system so my radiators are not as cold at the bottom from all the sludge gathered.

[@rodrigopr04]

Thank you, very helpful.

[@NickTaylorPlumbingLtd]

Hi Rodrigo, thanks for your kind words and taking the time to write a nice comment. If you haven't already please like and subscribe to my page as it really helps.

[@ashvanbro9329]

What happens then if your in bungalow all rads on one floor turn boiler off. Do you still open all the bleed valves and there are more drain offs.would you have to still drain if from all drain offs or just the one your working on

[@RickTOutdoorAdventure1969]

Cheers for that fella 👍

[@javeedsultan8484]

Before draining open all the valves on both sides of all the rads, that way all crap will hopefully be flush from the rads. you can buy cleaning solution that you add to the cental heating follow steps on product and how to use you mzy need to flush system after using the cleaning solution Important you will need to add an inhibitor to the system to stop crap buildup if you have belp it may be an idea once you've drained system is to take each radiator off and flush it in the garden with a hose

[@davidwalker4800]

What if I don’t have the said valve on any of my rads ?

[@NickTaylorPlumbingLtd]

Hi David, You'll need to do this in the link / video of mine below! kzbin.info/www/bejne/gpPSpImYa81gfKM

[@johnmcgill6011]

Great video thanks. Does anyone know if leaving water out of a system for an extended period of time can damage a combi boiler? I am taking most of the central heating pipes out and wanted to check first. By extended period of time I mean a couple of months

[@Hevva67]

I would like to know this too for different reasons.

[@passenger3]

Cheers buddy 👍

[@2paraairborne503]

Could you close all the upstairs rads except one drain downstairs so to saves time filling back up because all the upstairs rads are full except the one you use let air in upstairs

[@rayc1503]

Yes

[@joshfitzpatrick6201]

Hi Nick, great video. Quick question, do you not need to close the internal stop tap in your property before doing the work?. Or will the boiler not replenish if its turned off?

[@Finglesham]

I would say that the filling loop is off so no water will enter the system. This is for a sealed system of course NOT an open vented one.

[@juicysmollett255]

Thsts what I thought!

[@evieemaya88]

Great video nick. When draining the water down should your be opening up all the lock shields / TRV's . I want to drain my system to add a cleaner in it?

[@NickTaylorPlumbingLtd]

Hi Arts&Trusts, thanks for your message, before draining your central heating system down, turn the heating on, if all rads get hot then technically no you don't need to open them as the water is circulating properly. I would leave locks shields / TRVs as they are, add the cleaner and let circulate for the length of time specified on the cleaner. Then before draining the central heating system I would open all lock shields / TRVs fully, then drain, this would allow any larger debris to pass through the valves easier. Then refill. You'll need to rebalance your system afterwards which I have a video on so please check it out. Hope that helps. If you haven't already don't forget to like and subscribe.

[@evieemaya88]

@@NickTaylorPlumbingLtd thanks for the detailed response, you've earnt a subscriber sir. Lastly can I with adding cleaner, I have a heated towel rail up stairs and combi boiler down stairs. Am I right thinking to drain a litre of water out and then add the litre of the cleaner in and let that do its work for specified amount of time.

[@LBUK.]

What if the second half of the house doesn’t have a drain off valve? How can you get the remaining water out?

[@lukasg6254]

Thanks for this!! Nice and simple explanation!

[@jamesc5998]

Great vid, quick question... If I’m switching an upstairs rad to a towel rail do I need to drain the whole system, or just enough so that the top floor is drained?

[@itfben]

Can I do this to drain off all my radiators and remove them all to paint the house, on my Grant oil boiler system? I still want to have hot water though.

[@NickTaylorPlumbingLtd]

Hi Itfben, absolutly, although I would keep / leave on the bottom half of the house radiators whilst you paint upstairs and then vice versa! Once your done and filling back up, don’t forget to put some inhibitor back into your system, see my Amazon link below for my personal ‘best bits’ for radiators 👍 hope it helps; amzn.to/3RNYHFY

[@richardlewis5316]

I usually switch off all the radiators so they don't need to drain. Some water still in the pipe but it doesn't waste all the inhibitor.

[@seanriley8523]

Thanks great video 👍👍👍

[@NickTaylorPlumbingLtd]

Thanks Isaac always nice to have positive feedback.

[@katemackenzy5296]

Is there a way to drain the radiators ( to move them) while keeping the hot water on?

[@rayc1503]

If you've got a combi boiler link the thermostat control to stop the boiler firing on central heating. Close the return and flow whilst the system is pressured and your DHW should stay on demand. If you loose pressure your boiler will go into lockout. Drain the rest of the system 😉.

[@vincentchan3072]

Thank you this was very helpful

[@carmad1287]

Hi, i need to repair a bit of copper pipe i have slightly gouged with a drill bit, its not leaking yet but dont want it to in the future. I need to cut a bit of the pipe away and im planning on fitting a compression fitting. I need to drain the hot water that is in that pipe, is there a way to do this without draining all the radiators and everything? The tap its connected to is the kitchen sink, could i turn off the stopcock to the house and run the hot kitchen tap until it stops?

[@Edward-turtle]

if i folow your instructions and then turned water back on would it flush sytem round and back out of hose to flush it well and clean.all valves reclosed exept drain pipe valve.. is this right?????

[@garyeglington]

Nice video. At what point do you put inhibitor in the system?

[@NickTaylorPlumbingLtd]

Gary 70 thanks for the messege, you put the inhibitor in before you refill the system but after you’ve made all the alterations to the central heating system. 👍

[@clintador]

Great video Nick which has encouraged some other good comments. I plan to update radiators and valves whilst decorating through the house. Some pipework mods will be carried out so draining the system is required. My question is can I isolate and drain the central heating system on the boiler then switch on and use the combi for hot water only? This gives me time to complete the job over the summer at my own pace. Many thanks Nick. ps it's a Worcester Bosch Greenstar 42CDi Combi.

[@steves1460]

Did you get anywhere with your idea? I have a similar boiler to you and obviously we think alike i.e. whyy do you need ch pressure if you’re just heating hot water feed!? I suppose one way around this would be to put Speedfit stop-ends on the pipes and re-pressurise the CH if your idea didn’t work. You’d also have to be careful that the boiler would definitely not start-up in CH mode. Wonder if safety features would prevent this?

[@rayc1503]

Ok for this to work you'd need to link the thermostat so the boiler wouldn't fire if you were doing it for a long duration. Providing the boiler is still pressured and the isolation for flow and return are fully isolated. Then you can use the Dhw.

[@unapalomablanc]

Great video thanks for posting it

[@NickTaylorPlumbingLtd]

No problem Glad you found it helpful If you haven't already don't forget to like and subscribe. 👍

[@cv6717]

What do you do if the other drain off radiator was removed?

[@MuhammadKhan-yl7mt]

Good. I’m subscribed

[@NickTaylorPlumbingLtd]

Hi Muhammad, that's great news and thanks for your comment, I've got loads of helpful videos planned! A little busy at the moment as critical worker during lockdown but when things ease off I've got loads planned. Thanks again

[@grotbagsification]

Hi, do you have to turn the water off

[@swiggy03]

Great vid

[@jimreid9081]

Good video thanks. I have a property which will be left empty over winter hence looking to drain the system. Is this method suitable for this scenario? Or, is there a chance the supply pipe to the filling loop could freeze and crack? Thanks

[@rayc1503]

Turn off the mains water and drain from the lowest point i.e drain point cold water tap or outside tap. The central heating circuit would also need draining.

[@lanamc1963]

Hi, first time I watched your videos and very informative thank you. I hope you don’t mind me asking but are you basically saying if you switch off your boiler then no more water, other than what is already there, will go to the radiators. TIA

[@StaffordshireTravelAdventures]

ive got a radiater that has come away from the wall, being propped up by a stool, might have to get the council to do it.

[@waynenixon729]

No Inhibitor added to the system when you fill it with fresh water?

[@NickTaylorPlumbingLtd]

Hi Wayne thanks for your comment, its always advisable to add central heating inhibitor to they central heating system before you refill the system as it helps slow down the rusting process inside the radiators.

[@Echo-jg8is]

So the radiator water is independent to the mains water, so no need to turn of stopcock as its just the heating side?

[@NickTaylorPlumbingLtd]

Hi Echo, If you have a combi boiler or a pressurised cylinder (unvented cylinder) then you are correct, if you have a tank in the loft (gravity fed system) check out my other video on how to drain down a gravity fed system here - kzbin.info/www/bejne/aHiXmZmVfdiamJI If you haven't already don't forget to like and subscribe.

[@jackcalder6561]

Any inhibitor chemicals added?

[@NickTaylorPlumbingLtd]

Hi Jack, If you haven't already please like and subscribe to my page as it really helps. Yes you should add inhibitor once you've carried out all work and are ready to fill up, best to read the bottle on the quantity to put in as they all vary, as a guide, the inhibitor I use is a 1 litre bottle to around 10 average sized radiators. Hope that helps.

[@154electrician]

after doing this i can hear the water flowing thru my radiators when the heating is turned on , does this mean there is still air trapped?

[@CERELESS]

How can I drain my combi boiler heat system when I don't have a drain valve?

[@Charlie-te2tt]

Helpful. Thank you

[@keithdavis2818]

Why didn't you use inhibitor when refilling the system??

[@mattbond3981]

Legend

[@456Brian]

Hi I have a graverty fed heating system all the rads down stairs have a beed of valve do I need to put a pipe on each of them to bleed the system out thanks Brian

[@NickTaylorPlumbingLtd]

Hi Brian, thanks for your message, if you're looking to completely drain your system then yes. On some occasions you don't have to drain the system completely but for peace of mind it might be worthwhile to drain them all. If you don't drain the system completely use your spanners to open a nut and if it leaks your can tighten it back up rather than cutting some pipe and not being able to stop the leak quickly. Hope that helps? If you haven't already don't forget to like and subscribe.

[@456Brian]

@@NickTaylorPlumbingLtd thanks for the reply can I ask you one more I won't to put a filter on the system But there's no room as the boiler is up to the ceiling which pip in the airing cupboard do I put it on thanks Brian

[@rayc1503]

@@456Brian fire your heating and check with your hand which pipe gets hot 1st. That's NOT the pipe you want it on. The one which heats up after 👍.

[@nickcollins7568]

I have seen some systems where the installer has failed to install any drain offs whatsoever

[@NickTaylorPlumbingLtd]

Hi Nick, thanks for your message and nice name by the way. By rights all installations should have these drain off valves however your right sometimes there not fitted (original installer fail). There are a couple of ways around this which I'll post a new video how to do this soon especially fo you! Hope that helps. If you haven't already don't forget to like and subscribe.

[@wolfharthiphop]

What if your system doesn't have a drain off valve?

[@johnh1872]

What about anti corrosion additive. Guess u pore in radiator b4 refilling.

[@rayc1503]

1st test your system for leaks. Otherwise you've just wasted a bottle or more of inhibitor.

[@juicysmollett255]

Are you not suppose to turn off the main water supply that comes into the house first? Otherwise wouldnt it just keep fiiling up the roads and boiler! Just an observation.

[@NickTaylorPlumbingLtd]

Hi Juicy, thanks for the comment, you don’t necessarily need to turn the mains water off for a combi boiler, if you watch my video on how to drain down a gravity fed system then yes you do need to turn the water off. However. If in doubt turn the water off, it’s always best to be safe than sorry 👍

[@drippincolors]

Please help someone! None of the radiators in my house have a drain off valve. How do I drain the system?

[@jamesdevlin2143]

thanks!

[@spoonieAB3]

Do you need to turn off the water at the stopcock before you open the drain value?

[@NickTaylorPlumbingLtd]

Hi Matthew, thanks for your comment, there's no need to turn the water off at the stopcock for a combi boiler system. If you have a gravity fed system (tank in the loft) you'll need to turn the stopcock off first. I have a new video coming out this weekend on how to drain down a gravity fed system so don't forget to like and subscribe for loads more helpful videos.

[@spoonieAB3]

Much appreciated, Nick, thank you! Got a rusted TRV I want to replace at some stage but I think the stopcock is hidden behind a tiled wall from the previous owners so that’s really handy.

[@MegaVinny73]

No inhibitor before the refill !?

[@eugenevoltage1654]

Hi Nick, I appreciate this video thanks. On my ideal logic 24 combi, I had the valve on the CH flow (behind pressure gauge) in the wrong position while running tap to test after filling system. Looks like I've broken the pressure gauge and am planning to replace. The manual says to close all CH water isolating valves on boiler inlet, then drain system at CH drain point. Before finding that in the manual, I already drained as much water as possible from the CH via the radiators. Do you think that is sufficient so I can remove pressure gauge? Thank you.