The dreaded Flow Switch - Potterton Promax/Baxi Solo/Main Heat

[@MrVictorvolvo]

Brilliant video as always. Had one this evening and used the wet vac as the thing wouldn't stop dripping. Them clamps are a nightmare. The flow switch snapped off inside the boiler which wasn't fun, but all sort now. Video was a god send cheers!

[@yensabi]

Nice one , what a fantastic design of a boiler , only ever done one and had a problem re sealing the flow switch , got it after third attempt as it was rotten.....😡 cheers mate...👍

[@zoaibsharif877]

Good job. Can you confirm how you diagnosed it was the flow switch that was at fault? What were the symptoms?

[@simonbagley3571]

Stick a brass rad key in there to bypass it.. If it fires and runs without banging you know its that's

[@cputilitysolutions]

@@simonbagley3571 you can also use one of the 2 case screws to link it out, they're the perfect size to touch both probes 👍🏽

[@cputilitysolutions]

Boiler goes to a lockout sequence which when you follow the fault finding flow chart in the MIs it goes through different options. In this case the flow switch wasn't making when the pump was running and giving an open circuit which meant it had failed

[@lewishortertv]

@@cputilitysolutions Great video! Thanks. Think this is the issue with my boiler... I followed the fault finding diagram and mine is open circuit even with the pump running. When you mentioned by passing to test it, do you mean making a connection across the two pins in the PCB where this switch plugs in? Is there a risk in me doing this, and it not being the flow switch that's broken and actually a flow blockage or something and I blow the boiler up?

[@lewishortertv]

@@simonbagley3571 Think this is the issue with my boiler... I followed the fault finding diagram and mine is open circuit even with the pump running. When you mentioned by passing to test it, do you mean making a connection across the two pins in the PCB where this switch plugs in? Is there a risk in me doing this, and it not being the flow switch that's broken and actually a flow blockage or something and I blow the boiler up?

[@rodknee87]

Cheers, Havnt done one of these yet, good to see what I'm in for 👍

[@davelaye7003]

had one of these today, kept firing and then extinguishing, locked out after five times. found the condensate completely blocked (but dry inside). the condensate was running down R/H side casing inside. probably the water was stopping half wave rectification? then when I washed the trap out, water on the trap's electrical connectors stopped it from firing. as soon as removed the wire to the trap, ran fine. dried the trap in situ with a hair drier and it worked.

[@cputilitysolutions]

Yup that can catch people out! Good work on getting to the bottom of it

[@richardcampbell1932]

Thanks for the great video. I’ve got the same boiler, Potterton 12SL Promax. I was wondering if you could please give me some advice, I’ve been having further problems since changing the flow switch. I’ve recently changed out the flow switch as well, It worked well for the first day but today it started locking out. After firing up & working for 5 minutes, The water coming into the boiler is noisy. it was cutting out & all three lights were out on the PCB housing & the reset switch wasn’t working. For me to fire it up, I had to turn of & turn on the fuse coving the boiler on the house main fuse panel. The boiler isn’t flicking the fuse. I need to turn it on & then of myself. I would appreciate any advice to resolve this problem. Thank you in advance. Richy

[@cputilitysolutions]

Hi, sounds a bit of a strange one. Could be that some water could have gotten into the PCB when doing the flow switch. Are you a gas engineer yourself?

[@richardcampbell1932]

@@cputilitysolutions Thanks for your swift reply. I covered all the electrical parts with plastic sheeting before i drain the system. The drain point at the heat exchanger manifold was awkward to get access but i did use a funnel & pipe to drain off. I also dried off everything with a hairdryer before putting the cover back on & firing up. No, I'm not a gas engineer.

[@stevenjohnson6082]

most likely air lock, wont reset too hot and turning off then turning on is turning pump off then on again try and pull water through the boiler drain point

[@reliabill87]

What was the fault the customer said to change the flow switch?

[@bahiaharjinder]

Hey.. Agreed ball ache job also they leak and drip onto pcb and cause it to blow, i take it is closed circuit in rest and then goes open when working? Thanks for the video bruv 👍🏻

[@cputilitysolutions]

Thanks man, it'll be open circuit at rest and makes continuity when activated 👍🏽

[@bahiaharjinder]

Appreciate the response back Thankyou 👍🏽

[@paulrossiter9567]

Another quality fix 👏👏👍

[@proteus1]

I have an igiton issue on customers version. They said over phone, not igniting. Not worked on old boile like this before.

[@YoutubeHero666]

i have got one to replace its leaking at the bottom where it connects to the boiler. its in a cupbaord pipes go up and tight to the wall no compression fittings just a straight soldered coupler and the flue goes out to the side no room at all!! not sure i fancy this

[@javidmohammed9498]

Hello mate. Did you change the flow switch because you had a solid light and two flashing green lights due to no or reverse circulation? Thanks

[@cputilitysolutions]

I done this video a long time ago so I can't remember what the light sequence is for the fault, but I would have checked continuity across the switch and if I didn't have it then that's why I would have changed it

[@javidmohammed9498]

Thank you very much. Very helpful and that was a good 👍 video. Appreciate your reply.

[@cputilitysolutions]

@@javidmohammed9498 nice one thank you 👍🏽

[@sreviews6397]

I was looking to get a Baxi 800 heat only boiler installed but discovered that they own potterton and main. On the face of it these heat only models look the same. do you know if that's true for the internals or are there some differences? Or is the difference just the warranty lengths and getting a filter with a Baxi?

[@dan8789]

Hi My Potterton promax sl 15 looks exactly the same as this one but I don’t have an air pressure switch? Do you know why this is? Regards

[@cputilitysolutions]

Some models differ slightly

[@dan8789]

@@cputilitysolutions Thanks Do you know if there is a manufacturing date on these boilers anywhere?

[@sergd7885]

I have been watching your channel for a long time, I have baxi solo 2 pf the overheat lamp lights up and he does not want to turn on thanks for any help

[@stevieb6185]

I have the same issue and replaced the flow switch worked fine for 2 weeks but now gone again. I did notice there was sludge in the heat exchanger how would this be cleaned out?

[@cputilitysolutions]

Sounds like you probably need a powerflush if there's sludge in the system

[@hamzaparvais3948]

Looks difficult great video and tips

[@anthonyoconnell9333]

Help I have a question. I am putting in a new programmer I’ve lifted off the face of the old one and there are 2 red wires going into live, 2 blue going into negative and a loop going from the live to number 1 and a yellow going into 3. I’m a little confused can you advise please. Thanks

[@macpatel7810]

Nice explanation again CP. Somehow that does not look ideal. Lol. Would hate to think how difficult it would be if flue was to the right and flow and return pipework went upwards too. Would it mean complete drain down ?

[@cputilitysolutions]

Usually even worse when open vent system! It's a terrible design and yes I'd drain down to be safe as you got all those electric components below just waiting to be drowned!

[@macpatel7810]

@@cputilitysolutions drowned lol. I like that. Would it worth applying the bung method to feed and expansion pipes at the tank to keep a vacuum ? Or too risky.

[@cputilitysolutions]

@@macpatel7810 yeah you can bung the F&E, that's what I usually do, just gotta hope they hold and that there's no other way of air getting into the system otherwise it'll be trouble lol

[@macpatel7810]

@@cputilitysolutions I know what you mean. Very tense situation..

[@jameskale17]

GREAT VIDEO!! CAN ANYONE HOW YOU SEAL THE NEW ONE IN DOES IT COME WITH A SEAL OR DO YOU HAVE TO SEAL IT IN??

[@cputilitysolutions]

Thanks, it comes with seals and screws

[@manjsingh6500]

Top work

[@Smokeblow]

Still got it done mate well done

[@robbie2awesome]

I did one today, was easy peasy, drain down, remove bracket, uncouple flow pipe, remove flow switch, lube up new one and repressurise the system, test for leaks, took no more than 30 mins including going to the merchant for parts. All you need to do is cover the PCB casing. Panic over problem solved.

[@cputilitysolutions]

Nice one 👍🏾

[@RoobieRoo2]

Lolz only messing bro, it took longer than thirty mins, but system was unvented cylinder so no need to go in loft etc.abd bung up f n e tank. I used Screwfix black bags to cover the PCB and also to catch the residual water from opening up the pipes. Your vid was very helpful bro. ​@@cputilitysolutions

[@cputilitysolutions]

@@RoobieRoo2 haha nice one, I thought you must have had a right touch if you done it in 30mins 😂

[@happyslapper07]

Good work not to bad this one as you have access if was in a cupboard then it can be tricky

[@cputilitysolutions]

Very! Pain in the ass job any other day!

[@frankiepc8119]

i think if i was going to disconnect a compression joint and take out the pipe as well i would have put a compression cap end on the open ended pipe just in case the air lock failed . Good video though well done 😀

[@cputilitysolutions]

Luckily it was a sealed system so once I dumped the pressure out it was fine 👍🏽

[@faroyoussef1757]

Hello mate We got same boiler hot water working fine. But no heating although changed zone valve,thermostat and programmer. What could be the issue

[@cputilitysolutions]

@faroyoussef1757 whereabouts are you based?

[@gasfitter78]

I went to a job where the flow switch was replaced but the engineer that replaced it forgot the bracket! they used a cable tie and the clip to hold it together!

[@cputilitysolutions]

Too many cowboys out there mate

[@junxie1599]

super.

[@stevieb6185]

Hi mate where are you based?

[@cputilitysolutions]

Romford in Essex

[@darrenhooper3457]

horrible boiler hate them with a passion i always take the pcb out when i change the flow switch

[@cputilitysolutions]

My most hated boiler!

[@paulhughes8724]

I hate those boilers they must be the worst out there , not one good thing about them

[@cputilitysolutions]

Couldn't agree more!

[@paulgannon3261]

Great concept but the boilers themselves are rubbish. The seals around the case perish quicker than a mouldy banana. This causes the overheat to activate but there are two on this. Poorly made but so easy to fit and no need for a permanent mains live supply is the only reason to fit. If you have 4 wires go better than these

[@cputilitysolutions]

Agreed, I hate these boilers with a passion! The new Baxi heat only range is great though, same wiring as well, no pump overrun either, just switch, N & E 👌🏽

[@paulmusther4219]

Bad design.

[@cputilitysolutions]

The worst! I'd rather take a worcester off the wall and change the vessel!

[@paulmusther4219]

@@cputilitysolutions I don't think there hard to remove the top of the boiler .it doesn't take long .I've put an external vessel in cupboard with boiler as it's easier if there in al cupboard. Stay safe .