Boiler constantly needs resetting

[seagull]

Sorry if it's been covered before. My central heating boiler seems to turn itself off at irregular intervals - it can run OK for several hours and then next time will run for minutes before the "reset" button needs activating whereafter it is back to normal again for a period. When it switches off the pump is still running.

Any advice please?

 

[SparkyTris]

I just had this problem with a Potterton Suprima.
I re-flowed all the large solder connections on the PCB in the boiler (I actually saw some cracks in the solder joints) and it's been fine for the last 3 days.

It seems that the PCB's in the Potterton range are really poor! The job I carried out was quite easy, just need to be a bit handy with a soldering iron. If you want to try it, I'd be happy to send details of what I did!

 

[Baxi-Remeha]

just hope you havent damaged any of the safty device circuits...........BANG.....................

 

[seagull]

yes. mines a Suprima too!

However, my expertise does NOT mirror yours so I will leave well alone and pay for someone to sort it!

Many thanks for the replies.

 

[seagull]

Sparky:

Would you be able to send details as you suggested? My email is [email protected]

Many thanks

(I did have a look on www.potterton.co.uk but it was no help)

 

[ChrisR]

NB retailo price on a replacement pcb is £230. + fitting.
You can get a board and fit it yourself. Do a Search on Suprima - there are lots recently.

 

[bobb]

My central heating boiler seems to turn itself off at irregular intervals - it can run OK for several hours and then next time will run for minutes before the "reset" button needs activating whereafter it is back to normal again for a period. When it switches off the pump is still running.

I had this problem with my worcester bosch. One of the experts on this site diagnosed a faulty divert valve. When changing from hot water to central heating, the valve was sticking and causing the water in the gas to water heat exchanger to overheat and hence overheat and trip.

Changed the divert valve, problem solved.

 

[bobb]

sorry, did it wrong before

Sorry if it's been covered before. My central heating boiler seems to turn itself off at irregular intervals - it can run OK for several hours and then next time will run for minutes before the "reset" button needs activating whereafter it is back to normal again for a period. When it switches off the pump is still running.

Any advice please?

had the same problem with my worcester bosch.

was advised by someone on the site that it could be my diverter valve. when going from hot water to central heating the valve was sticking. this caused the water in the gas-to-water heat exchanger to overheat and thus trip.

changed divert valve, problem solved.

 

[SparkyTris]

After a careful study of the PCB, I would have to say that it would be *very* tricky to inadvertently disable the safety functions on the board: there is a microcontroller on the board that runs a self-checking routine prior to fire-up, and if it finds anything out of order with the sensors then it will cause a lockout condition. The sensors seem to be mainly "active-low" as well which makes it even harder to lull the CPU into a false sense of safety.

 

[bathjobby]

Agree with SparkyTris on state of Potterton PCBs. My Netaheat was fine for 12 years then boiler started to intermittently stop and sometimes gas inlet valve would bounce (rattling on and off several times a second). Checked with meter and saw power to valve bouncing, ruddy horrible (should have failed eyeball QA check even 12 years earlier) dry solder joint on circuit board feed to valve. Been fine since re-soldered, 3 years.