Potterton Suprima 50 Lock Out problem

gas4you

Not really.

I can only say that if it resets straight away then it is usually the board.

If it won't reset for a while, then it is due to overheating.

As this job entails removing the combustion chamber door and fan, it is a job for a RGI, not DIY.

28ward28

My boiler had the lockout problem intemittantly around 2005 and then got so bad I had to fix it. Being an Engineer and keen fixer of everything I set about the task. I had great difficulty locating the cause of the problem as I didn't have all the circuit diagrams etc. but in the end I found some usefull information posted elswhere. Basically they had repaired the PCB by replacing components for about £10. I soon confirmed my boiler had the same faulty component and replaced it - had to "make it fit" as it wasn't exactly the same footprint. The boiler worked fine for another 6 years until the same fault came back. This time there seems to be something a little different as one of the realys is not switching at all. I am in the process of getting some replacement driver transistors as the rest of the PCB seems to work OK.

The fault is caused by bad contacts on one or both of the relays associated with the fan. The contacts become dirty and then switch power intermittantly. If after a short period of time the diaphram switch does not indicate the fan has started a lockout occurs.

There have also been numerous cracked solder joints on the PCB and after fixing them it worked much better. Caution - it is very easy to lift PCB tracks when reoldering joints. My PCB has several tracks replaced by wire links.

Update:
Found the installation manual online and followed the diagnostic tree which told me to change the PCB which is what I suspected. From past experience I knew it was around the relays and as the fan does not start its almost certainly the relay that controls the mains to it.
I checked out the transistors driving the relays and they all worked fine. The drive signals to these transistors were also fine. Scratched my head for ages then tried bypassing the output transistor just to see if the fan would start, andit did. However, I had not bypassed the transistor directly at its terminals so I checked the PCB tracks from the transistor to the relay and found the broken track. It was not visible even under a magnifyier but after repair the boiler works OK again. Took a few hours but saved loads of money.

After having loads of PCB faults like this I can see the error of Pottertons ways, the PCB heats up a lot in its position and the expand and contract cycling eventually fractures the joints and tracks. I have placed a pad of ceramic insulation between the case and the PCB to reduce the heating effect, maybe it will last another 6 years, then I will get a new one, Valliant.

Interestingly, other boilers mount their PCBs at the base of the body, the coolest place.

If you follow the installation manual fault tree and it says its the PCB, then that is correct. If you can use a soldering iron inspect the joints and tracks and repair as necessary. The two adjacent relays can cause intermittant failures after several years due to corroded/dirty contacts, replacing them with better ones at < £10 is faily straightforward, even if its not a leg for leg replacement - just link to the PCB with wires.

Roost

28ward28 wrote: »

My boiler had the lockout problem intemittantly around 2005 and then got so bad I had to fix it. Being an Engineer and keen fixer of everything I set about the task. I had great difficulty locating the cause of the problem as I didn't have all the circuit diagrams etc. but in the end I found some usefull information posted elswhere. Basically they had repaired the PCB by replacing components for about £10. I soon confirmed my boiler had the same faulty component and replaced it - had to "make it fit" as it wasn't exactly the same footprint. The boiler worked fine for another 6 years until the same fault came back. This time there seems to be something a little different as one of the realys is not switching at all. I am in the process of getting some replacement driver transistors as the rest of the PCB seems to work OK.

The fault is caused by bad contacts on one or both of the relays associated with the fan. The contacts become dirty and then switch power intermittantly. If after a short period of time the diaphram switch does not indicate the fan has started a lockout occurs.

There have also been numerous cracked solder joints on the PCB and after fixing them it worked much better. Caution - it is very easy to lift PCB tracks when reoldering joints. My PCB has several tracks replaced by wire links.

Update:
Found the installation manual online and followed the diagnostic tree which told me to change the PCB which is what I suspected. From past experience I knew it was around the relays and as the fan does not start its almost certainly the relay that controls the mains to it.
I checked out the transistors driving the relays and they all worked fine. The drive signals to these transistors were also fine. Scratched my head for ages then tried bypassing the output transistor just to see if the fan would start, andit did. However, I had not bypassed the transistor directly at its terminals so I checked the PCB tracks from the transistor to the relay and found the broken track. It was not visible even under a magnifyier but after repair the boiler works OK again. Took a few hours but saved loads of money.

After having loads of PCB faults like this I can see the error of Pottertons ways, the PCB heats up a lot in its position and the expand and contract cycling eventually fractures the joints and tracks. I have placed a pad of ceramic insulation between the case and the PCB to reduce the heating effect, maybe it will last another 6 years, then I will get a new one, Valliant.

Interestingly, other boilers mount their PCBs at the base of the body, the coolest place.

If you follow the installation manual fault tree and it says its the PCB, then that is correct. If you can use a soldering iron inspect the joints and tracks and repair as necessary. The two adjacent relays can cause intermittant failures after several years due to corroded/dirty contacts, replacing them with better ones at < £10 is faily straightforward, even if its not a leg for leg replacement - just link to the PCB with wires.

Good info here mine acting up now on pcb no 3 since year 2000. Anyone got a decent diagram of the pcb ? Mine is mark 2 pcb i think . black button. I going to have good crack at it before I buy another pcb.

anyone anyone pls.

RJL77

Hi, apologies for jumping in on this post. We have just moved in to a house which has a ~15 year old Potterton Suprima with BoilerMate II system. Last night, the Potterton boiler cut out and it is now just flashing red on the board. We have the board with one light and the black reset button. If I press Reset, it doesn't appear to reset immediately. If I turn the power off and on, it comes back on, flashes green and yellow for a while and then reverts to the flashing red. Basically, the boiler never gets going and the pilot light does not come on....any suggestions would be greatly received!

Thanks,
Rich

southcoastrgi

RJL77 wrote: »

Hi, apologies for jumping in on this post. We have just moved in to a house which has a ~15 year old Potterton Suprima with BoilerMate II system. Last night, the Potterton boiler cut out and it is now just flashing red on the board. We have the board with one light and the black reset button. If I press Reset, it doesn't appear to reset immediately. If I turn the power off and on, it comes back on, flashes green and yellow for a while and then reverts to the flashing red. Basically, the boiler never gets going and the pilot light does not come on....any suggestions would be greatly received!

Thanks,
Rich

unfortunately due to one idiot on here thinking it is ok to DIY repairs to his boiler my advice is going to be some what lacking, i can think of at least two things that need checking however both of them req access to the combustion chamber which is not a diy job, you need to get a RGI to look at it, but check & make sure the pump is running first

chillax

Our Suprima was fitted in 1998. We have so far required 2 new circuit boards, each costing £300+. Now we are having more problems with the boiler switching on when it feels llike it. We've had the engineer to look at it and he was perplexed but thought it was the air pressure switch, now replaced at a cost of £80+vat. However, it is still not working properly. The boiler has been serviced every year since installation and yesterday we paid out £192 for that part, installation and the annual service. What can one do???? It is so frustrating. Has anyone any ideas? What we need is an experienced service engineer to give his views. I am appalled that Potterton chooses to cold shoulder these problems.

RodneyP

My Potterton Suprima HE has just started locking out. The lights go red. I have been turning the temp control of as highlighted on the instructions, then turn it back to the desired temp, the lights go green, it makes the usual noise when it's fired up but I can't see a flame? After about 2 minutes the lights go red again, the boiler continues to make the usual sound but still no flame is visible? I have read on forums this is probably the PCB which looks easy enough to replace but I'm not sure if it is the PCB as when it starts up again after re-setting there is no flame? I would be grateful of any advice, baby on the way so the worst time for me boiler to go 😔

jbainbridge

RodneyP wrote: »

My Potterton Suprima HE has just started locking out. The lights go red. I have been turning the temp control of as highlighted on the instructions, then turn it back to the desired temp, the lights go green, it makes the usual noise when it's fired up but I can't see a flame? After about 2 minutes the lights go red again, the boiler continues to make the usual sound but still no flame is visible? I have read on forums this is probably the PCB which looks easy enough to replace but I'm not sure if it is the PCB as when it starts up again after re-setting there is no flame? I would be grateful of any advice, baby on the way so the worst time for me boiler to go 😔

Sounds very much like the pcb has gone. Ours went over the summer. Cost about £250 to get it replaced.

If it does go again I'd be tempted to get a refurb one and do it myself - http://www.cetltd.com/default.asp?part=1702&desc=Potterton-Suprima-Pcb-114954-5102160-5102160

I know there's never a good time for unexpected expenses ... at least its being replaced now while the weather is still incredibly mild rather than the middle of winter. And I've now got an old pcb I can swap for a refurbed one when the time comes!

SGM1

chillax wrote: »

Our Suprima was fitted in 1998. We have so far required 2 new circuit boards, each costing £300+. Now we are having more problems with the boiler switching on when it feels llike it. We've had the engineer to look at it and he was perplexed but thought it was the air pressure switch, now replaced at a cost of £80+vat. However, it is still not working properly. The boiler has been serviced every year since installation and yesterday we paid out £192 for that part, installation and the annual service. What can one do???? It is so frustrating. Has anyone any ideas? What we need is an experienced service engineer to give his views. I am appalled that Potterton chooses to cold shoulder these problems.

I'd ask for my money back, an air pressure switch will never cause the boiler to fire with no demand. More likely motorised valve,clock or frost stat problem. Impossible to diagnose over internet obviously but replacing APS was a complete waste of time and money

dia79

We have a Potterton Suprima 50 L and for couple of weeks it has been locking out, it starts straight away some days, mostly mornings, but in the evenings, it might take half an hour to fire up, or it fires up straight away and half an hour later stops, as if it has reached the temp in the thermostat, although it might take another half an hour to fire up again, by which time the radiators have become cold and the house is freezing. We have replaced the 3 way valve and the thermostat, but no luck. I am suspecting it is the pcb after reading all the comments on the forum. Where can we get a reasonably cheap one and how hard is it to replace it ourselves?

Thank you