Puma 80 problem - burners stay on

[vladman]

Hi all.

I've been searching the net for possible clues or pointers as to what may be wrong with my boiler, and stumbled across this forum. I've now read through many threads, some concerning the exact model of the bolier I have, and I'm hoping I too will be able to benefit from the knowledge the experts here are so kind to provide.

I'll attempt to provide all the necessary information, so that someone may hopefully be able to diagnose my fault(s).

The boiler's been broken since about March/April this year. The problem started one day when the burners didn't shut off, after the hot water tap was turned off. The boiler soon started making loud noises, and it then shut down, presumably some sort of safety mechanism cutting in. This also started happening with central heating too.

I then had a repair-person from a local plumbing company come out, and he "fiddled" and prodded and declared that the valve that controls the hot water flow was faulty and needed replacing. He did manage however to get the central heating to work fine, the burners came on, the radiators got hot, and the burners then stopped, and everything seemed fine. He left, and I thought all I have to do is have that hot water valve replaced. Unfortunately, the next time I tried to use central heating, the same thing happened again, with the burners staying on, until the safety cut in.

It's now about to get colder again, and I can't put this off any longer. I'm horrified by how expensive it would be to replace the boiler, and before going down that route (if it turns out I have no choice), I'd like to be as certain as possible it's impossible/uneconomical to repair my existing boiler.

I'm fairly DIY competent, but have zero experience when it comes to plumbing. Based on what I read in some other posts I found here concerning this particular boiler, I've had a look at the PCB, and as soon as I switch the mains on (with the boiler switch in standby), the red LED on the PCB comes and stays on. The Fault Finding diagram in the manual says this indicates that the Hot Water Flow switch should be replaced. I have also (carefully, and with the mains switched off) unscrewed the PCB, and found no signs of sparking or burning anywhere on the back (in particular in top left).

I was hoping someone here may be able to offer some advice based on my description of the problem above.

The boiler is about 8-9 years old.

I'm in Northolt, Middlesex.

Very grateful in advance,

Vlad.

 

[oakland99]

it does sound like water flow switch and needs replacing this is a common fault with puma boilers but is easy to change ( replace micro switch flow valve activates as well) ,,.whilst not to bad to work on these boiler do have a long list of faults. you shouldn't need to replace boiler just call a decent corgi eng with experience on these boilers...

 

[kevplumb]

na what you really need to do is replace the full system then worry if the walls are strong enough to carry the weight on the boiler and new rads

failling that get the dhw flow switch changed

daft job and i would say one of the commonest faults with the boiler

more so in a hard water area

 

[vladman]

Wow, what an active place this is, my post was nearly 10 pages down, haven't had the chance to check the forum in the last couple of days.

Thanks for the advice guys.

But if I understand correctly, the systems controlling hot water and central heating are two independent systems, right?

I'm having this problem with both the hot water and central heating (the burners not shutting themselves off). So is there another thing that's failed that controls the shutting off of the burners when central heating is used?

I don't know if it's against the forum policy, and if so, I apologise, but can someone recommend someone in my area who I could get in touch with regarding this as I need to get this sorted reasonably quickly. I'm in Northolt, Middlesex.

Many thanks in advance.

 

[Softus]

Wow, what an active place this is, my post was nearly 10 pages down, haven't had the chance to check the forum in the last couple of days.

Then use the "Watched Topics" feature.

But if I understand correctly, the systems controlling hot water and central heating are two independent systems, right?

No - there are some unique parts that control each function, but many parts of the boiler are common to both.

I'm having this problem with both the hot water and central heating (the burners not shutting themselves off). So is there another thing that's failed that controls the shutting off of the burners when central heating is used?

Possibly, but what might be happening is that the flow switch is sticking on, so after the heating shuts off the boiler remains alight until it overheats [again].

I don't know if it's against the forum policy, and if so, I apologise, but can someone recommend someone in my area who I could get in touch with regarding this as I need to get this sorted reasonably quickly. I'm in Northolt, Middlesex.

First ask friends, relatives, neighbours and colleagues to recommend someone they've used and are happy with. If you luck out then call CORGI (or go to the web site) and find one that way.

Remember that whoever does the work professionally is legally required to be CORGI registered if they touch any gas components - ask them nicely to bring their card with them so that you can confirm it.

 

[Agile]

Your boiler thinks its providing DHW so it will not turn off BUT it should heat up the radiators while thats happening!

Are you sure you have not got a dripping hot tap?

You might have a slightly faulty PCB which does not run the pump during DHW usage!

Make sure anyone repairing your boiler does understand them!

Tony

 

[vladman]

First ask friends, relatives, neighbours and colleagues to recommend someone they've used and are happy with. If you luck out then call CORGI (or go to the web site) and find one that way.

Already done that, no luck.

Ok, thanks for your suggestions guys.