Potterton Suprima

[BigD]

I've got the all too familar lockout problem (flashing red light, reset required). However, this only happens when the CH is called for. We have had no problems for the past week or so with just the hot water on. Called a plumber and suggested to him this may be the PCB (after reading this forum).

He has been today and told my wife that it is the CH pump. Not looked at the PCB. He's coming on Monday to replace pump.

Is this the likely cause given the above scenario or should I insist he look at the PCB before letting him go ahead with replacing the pump. If this doesn't solve the problem, should he put the original pump back on and refund me or what? I don't want to question his judgement, but at the same time, I could do without the hassle!!!!!

Guidance greatly received. Thanks.

 

[ChrisR]

Hmmm, psychic plumber? Or did he do a bit of diagnostic work?

How old is system/rads/boiler/pump, and which Suprima is it?
Tell us about any motorised valves and thermostats.

If it really IS only locking out on HW then I wouldn't suspect the pcb cos it doesn't know why it's getting het up.

So it may well be either
#1) overheating or
#2) thinking it's overheating.

It isn't difficult to measure the temperature the output water is reaching to decide which of those it might be.

If you turn the boiler temp right down, it shouldn't get as hot so should overheat less, if the temp controls are working

#1 happens eg if the water flow rate through the boiler is too slow for it to manage, or the gas rate is too high. Some are more sensitive than others - which Suprima is it? (Some have a flow switch too)

If the flow rate is too low, it can be
a) worn /blocked pump
___An engr can check the speed of the pump but otherwise it's hard to tell why circulation is poor. Checking pumps can sometimes be done without removing them if you have the kit, which not many do. Pumps block and impellers fall off, too.
b) HW circuits sometimes have a "balancing valve" in them which can be adjusted to increase flow.
c) air lock
d) sludge/scale in the system, but tends to affect CH too.
e) a restriction in your motorised valve - what have you got?

#2 happens if the sensor or overheat thermostat needs replacing. That's a quick/easy job for a corgi, and if it proves to be wrong, hell he can always put the old ones back.

All perfectly straightforward - apart from the things I haven't thought of/don't know about, and it'll probably be the pcb anyway which is bound to go sooner or later

 

[BigD]

Chris

Its a Potterton 50, complete system with new house 5 years ago. Don't know about motorised valves etc

Just to clarify, it only locks out when we need CH, fine with just HW.

 

[broxy]

Call potterton heateam out and they will fix the problem for £220 and it also gives you a years cover on the system.
New PCB board costs £184 without fitting which they will probably replace anyway.So the £220 is well spent and they will have you up and running that day.

 

[BigD]

So what you're saying is if it is the pump, Potterton team will end up replacing pump AND PCB for £220?

 

[ChrisR]

SOrry I got hw/ch swapped.
The 50 doesn't suffer with overheating as much as the bigger ones.
No they won't change things which don't need it, nor the pump as it isn't part of the boiler.

You should do a little searching on motorised valves - you'll find what you need to know in less time than it takes us to give answers..

 

[bones001]

have a look in the fault finding section of the manual, it will tell you the possible faults compared to how many flashes it does per second for instance. the old boards do have a known fault that makes them lock out or just wont come back on after the temp is satisfied but its a bit weird if its only doing it on one or the other of ch or hw as the boiler does not differenciate between the two and doesn't need to know if its heating ch or hw. i have a manual if i can dig out if needed.

 

[ChrisR]

The manual is on the Baxi/Potterton website and partsarena.com/baxi

 

[BigD]

Thanks guys for the replys. I'm gonna let the plumber come on Monday and take it from there.

Bones - which model board you got for £100?

 

[markvirgo]

I have a potterton suprima 40 and the pcb is the same. it has a newer pcb fitted and worked perfect which is not needed now. you can have the pcb for £10+p&p. or the whole boiler for £20 i just need the space.

A refurb is the reason for the boiler being not needed and i guarantee it.

I am in enfield north london.

Collection is most welcome

 

[ollski]

I have a potterton suprima 40 and the pcb is the same. it has a newer pcb fitted and worked perfect which is not needed now. you can have the pcb for £10+p&p. or the whole boiler for £20 i just need the space.

A refurb is the reason for the boiler being not needed and i guarantee it.

I am in enfield north london.

Collection is most welcome

Can't argue with that, I'd have it myself if you were closer.

 

[geoff@cetltd]

A refurb is the reason for the boiler being not needed and i guarantee it.


??

 

[BigD]

Ok - plumber came on Monday and replaced CH pump. Tried CH today and boiler tripped out again (flashing red light). Already paid him £176 to replace the pump and the cheque has gone through. How should I play this?

Was thinking I should ask him to replace the PCB for free seeing as I have already paid him £176.

 

[ChrisRoberts]

So u read all the posts about pcb problems and still let someone change the pump. Now u want it fixed for free. Can't see that happening unless U are good friends with the guy. Probly just stop answering your calls. When he told U it was the pump and you'd read about the problems I think U shoulda called someone else. £176 for a pump change is good money. I charged someone £90 the other day and thye nearly fell through the floor. Must be my honest face.

 

[geoff@cetltd]

Just a minute

Do we have a case of a CORGI fitter incorrectly diaqgnosing a problem?

surely not