Potterton Suprima 60L Problem

[CEC]

I've had this boiler from new for about 7 year with no problems so far. Recently it's started going offline occasionally. It seems to be ok if central heating only is used or central heating and hot water. However, with only hot water it's resetting itself.

I've seen loads of complaints about faulty PCBs on this model so I've checked the part number of the PCB in my boiler and it looks like the new model number. There is no sign at all of any burning or heat damage on the board.

All the valves in the system are opening and closing as expected but when it trips it seems to leave the pump running.

Any thoughts greatfully received.

 

[rojaca]

Could you describe what the led on the front of the boiler is showing when it locks out?

 

[CEC]

Flashing red. When I press reset the green comes on, the fan comes on, and sometimes it restarts and sometimes it resets back to flashing red again.

In my first post I said that the CH seems to be fine. Well I spoke too soon. It's just reset with only the CH on.

 

[powell30]

PCB.

 

[nickso]

you sure you have the new version pcb? you cant really see the board without removing the grey cover on the new version.

 

[Mr Smyth]

There is no sign at all of any burning or heat damage on the board.

On the new PCB's the circuits etc are enclosed in a grey plastic box. I you can see the resistors, circuits etc then I suggest you have an old style board.

If it only happens on HW then it suggests a circulation issue. The heat is not dissipated on the small HW circuit and as such overheats. Are all you rads heating well? is the bypass sufficiently open? From what you say the pump overun is working

I would suggest changing the thermistor and the OH stat before the board.

If it is a new style PCB then you can count the flashes after reset to find out if its failed due to overheat or ignition.

Hope this helps

 

[CEC]

Ah, maybe I do have an old PCB. It's in a drop down metal enclosure and can be clearly seen when accessed. I'm pretty sure it's not in plastic. Can't do it now but I'll have another look tomorrow to confirm.

Rads are all heating normally.

Thanks very much for all the help. Much appreciated.

 

[nickso]

in that case its almost certainly the pcb at fault. i would buy a new one too, recon units seem to be false economy more often on suprimas than other boilers. they can be pricey new and its often better to get a fixed price deal from one of the utilities or baxi/potterton themselves.

the thermistor and OH stat almost never go faulty on suprimas.

 

[baxpoti]

OH stat almost never go faulty on suprimas.

except when you find the leads welded on and the stat fall to bits trying to get them off. ...... . and you haven't got a spare one on the van............. and it's a Saturday

 

[nickso]

OH stat almost never go faulty on suprimas.

except when you find the leads welded on and the stat fall to bits trying to get them off. ...... . and you haven't got a spare one on the van............. and it's a Saturday

thats only happened to me once, even then it was my heavy handed apprentice who broke it. he failed to carry out the most reliable way of levering them off without breaking the stat.

i'm sure i will break one tomorrow now.