Potterton Suprima 40 problem

[nmg196]

Hi,

I have a Potterton Suprima 40 boiler in a standard setup. I have this problem whereby every day or two, the boiler will randomly turn off and flash it's red LED which means it's overheated. During this time, the pump is left on and the boiler won't fire again until I open the front cover and press the reset button.

What might be causing this? I've tried adjusting the thermostat temperature on the boiler but it doesn't seem to make any difference. Sometimes the boiler overheats when all the radiators still seem to be cold.

The pump appears to be working OK but does make a funny clicking noise if you turn it up to full speed, but is definitely pumping water because you can hear it running round the rest of the system.

Any ideas what might be causing this problem? Potterton want £245 to come out and fix any problem (including parts) and warned me that some parts cost £200 anyway. It seems very expensive bearing in mind I don't yet know what the problem is. What should I do?

Nick...

 

[Gasman1015]

Just do it, your boiler is a dog.

 

[ChrisR]

The pcb's are ever so well known, true celebrties in fact, for "locking out". Assuming yours is a few years old, that is. If it's really overheated, there are things you can do. SO does it lock out when it's not hot?

And are you handy with a multimeter?

And do a search on suprimas.

 

[ollski]

BG will do the job for 132 or for 120 if you are an energy customer diagnosis, all parts and labour and guarantee included....got to be a bargain when you consider the board alone could cost you 200.

 

[gazthepottertonengineer]

i think you might need a new pcb kit mate no let me say that again you do need a new pcb kit

only problem with british gas is

1 getting them to answer the phone

2 they will turn up and say it needs a new pcb and take a week to get the part meaning you have to take 2 days off work

where as all potterton engineers carry the parts on there vans

 

[ChrisR]

i think you might need a new pcb kit mate no let me say that again you do need a new pcb kit

Not arguing at all, but the fellah mentioned overheating.
If it pops and bangs and rumbles then stops while wheezing like a steam loco trying to drag me out of bed, you'd look at that first?
You'd obviously still have the parts on the van, but spose it's the system's fault?

 

[gazthepottertonengineer]

i think you might need a new pcb kit mate no let me say that again you do need a new pcb kit

Not arguing at all, but the fellah mentioned overheating.
If it pops and bangs and rumbles then stops while wheezing like a steam loco trying to drag me out of bed, you'd look at that first?
You'd obviously still have the parts on the van, but spose it's the system's fault?

if it is system fault we carry most makes of 3 port valves and pumps all which is included in price plus a years warranty as well

 

[ollski]

i think you might need a new pcb kit mate no let me say that again you do need a new pcb kit

only problem with british gas is

1 getting them to answer the phone

2 they will turn up and say it needs a new pcb and take a week to get the part meaning you have to take 2 days off work

where as all potterton engineers carry the parts on there vans

Gaz I'm not one to argue and couldn't really care who does the job, but suprima boards are such an unreliable component they are almost universally carried as van stock and as long as the parts are in stock and ordered before 6pm they arrive the next morning....the only exception to this is where the parts are special order or obsolete and need to come from the manufacturer in which case a week is certainly possible

Getting through on the phone is a fair point, but as you know it's light up time and thats a pretty universal problem.

 

[nmg196]

So it's not likely to be something more simple like the thermostat? I've drained and refilled the system as it's not been done in 7 years, but the water came out surprisingly clean. The only sludge was in the expansion tank but I cleaned that out too. (And yes, I remembered to put some inhibitor back in)

Are there any cheaper sources for parts on the 'net other than buying from Potterton? £150-200 for a boiler PCB is obviously a rip off - they're very simple and you can buy a decent computer for that kind of money which is several hundred times more complicated than a board which just controls a few relays.

It seems to trip less often if I turn the boiler thermostat right down (but the radiators still get untouchably hot - even on setting 3 (out of 10).

 

[gazthepottertonengineer]

by all means try replacing the thermistor first as this is a matter of pounds if you look carefully at your pcb you will see it is scorched in the middle

but if it still keeps locking out you are looking at a new pcb kit i say kit because it is not just a pcb as it is a differant make to your old pcb you will need to replace the whole wiring harness as well which comes in the Kit these kits do sell on Ebay for around £100 if you are happy to do it yourself as they do come with full instructions


Good luck Gaz

P.S when you do a search on Ebay spell Suprima correctly

 

[nmg196]

Thanks Gaz. I might try that then. Are the new PCB kits going to be more reliable? I thought Potterton were suppose to be reliable - but I'm not a plumber so perhaps I've got the wrong end of the stick.

Annoyingly it hasn't needed resetting in the last few days at all since I posted about the problem. Don't you just hate intermittent faults?!

 

[gazthepottertonengineer]

Thanks Gaz. I might try that then. Are the new PCB kits going to be more reliable? I thought Potterton were suppose to be reliable - but I'm not a plumber so perhaps I've got the wrong end of the stick.

Annoyingly it hasn't needed resetting in the last few days at all since I posted about the problem. Don't you just hate intermittent faults?!

Time will tell really i havent been back to any yet so thats a good sign but they have only been out about a year so who knows

still its not bad if thats the only thing to go wrong with your boiler in 7 years

 

[ChrisR]

If you can measure a few things with a multimeter you can find out if yours is one of the maybe 10% with your symptoms which isn't the pcb.
If you need anew pcb, it's a corgi only job to fit it. Much more than just the pcb gets changed, and more besides, gets disturbed.

 

[nmg196]

I'm handy with multimeter having done A-Level Electronics, but obviously I'm not really sure what I'm looking for on this system. As it's an intermittent fault, it might be hard to determine that a component is faulty if it's only faulty some of the time. I think I'll probably have to shell out for a pro.