Potterton Suprima 40 boiler

[susyshoes]

hello again. i have a potterton suprima 40 boiler in the kitchen which has been in the house since it was built some 10 years ago. sometimes the boiler doesnt come on when it should do and i have to press the reset button so the red light goes off. sometimes this works first time and sometimes it takes 3 or 4 attempts. it sometimes just goes off when it feels like it mid timer cycle. Also my pump which is in the airing cupboard keeps going when the heating has gone off, and sometimes its going all night which is annoying to say the least. i have to turn the speed down to make it a little quieter as the airing cupboard backs onto my bedroom. Do you think the two are connected? As everthing is intermittent i cant work out what, if anything is making this happen. we've only lived in the house about a month (rented). you helped me sort the shower problem out (needed a new solenoid) and i hope you can help with this too. many thanks.

 

[Happyplumber]

Sounds like you have the early version PCB,this may need to be changed,call your landlord and get him to sort it

 

[susyshoes]

landlord is a 'she' and she would rather i sort it out and she pays!!! i dont mind doing this as it means it gets sorted. whats a PCB?

 

[adlplumbing]

printed circuit board

 

[susyshoes]

thanks, is this in the boiler? Do you think the overrunning pump and the boiler not coming on are connected?

 

[adlplumbing]

are do your rads get hot at the bottom

 

[susyshoes]

we live in one of those 3 storey houses. the middle floor and top floor rads are fine and heat up fully, (when the boiler comes on) but the ground floor ones dont come on at all (except for one in the cloakroom). they have all been bled. when our plumber came to fit the solenoid for the shower he re balanced them and they worked for a day then went back to not working on ground floor.

 

[MeldrewsMate]

Reinforcing what HappyPlumber wrote, if it is the (almost 'normal') 5 years + PCB failure, you may observe that the reset button needs to be operated more and more frequently, however there is one other cause of the regular reset problem, and this is the failure of the overheat 'stat. As this is much cheaper than a new PCB your L/L may opt for this to be replaced as a first step....and I just remembered; the later Suprimas had a flow switch incorporated into the flow pipework which (from memory and subject to correction by others) interrupts the "overheat" signal, and may lead to a similar symptom.

I must add that the replacement PCB is not the same design as the old version and involves interferance with the boiler casing seals, thus it must only be done by a Gas Safe registered fitter.

Your landlord should be responsible for its rectification.

MM

 

[susyshoes]

ok, thanks for all of this. So does the pump not switching off some of the time have something to do with it too? or is that a separate issue?

 

[tonybhoy]

If the red light isn't 'flashing' when you 'reset' the boiler then the problem is not inside the boiler i.e. it's an external problem. Controls, stat pump etc.

If the red light is 'solid' when your trying to reset then it's an external problem as above however I would change the OH stat and primary thermistor which has already been said above and for the same reasons.

Sounds like the pump to me.

 

[Agile]

ok, thanks for all of this. So does the pump not switching off some of the time have something to do with it too? or is that a separate issue?

You seem to be adding problems as you go along.

If correctly wired then the pump over run is controlled by the boiler PCB.

Some run until a certain temperature is reached and others run for a fixed period of time.

Tony