Potterton Netaheat 16/22 cutting out

[john1000]

Hi - can you help? My Netaheat 16/22 Electronic is cutting out. It was installed in 1987, serviced every 5 years-ish... (last flushed+Fernox in '96) . It starts normally on the twice-a-day timer schedule, runs fine, heats the hot water and the rads OK, then after a few minutes, it cuts out and won't come back on again in that cycle, for rads or hot water. Gradually the rads cool down and we begin to freeze! The fan and the pump are still running and I can see the electronic spark sparking through the window, but the main boiler doesn't want to light. Could it be a faulty gas valve (hard to find+expensive 907219)? Or boiler thermostat? Or flue (the wisteria tendrills grew into it last summer and had to be hauled out). Or something else? I have a mate who's a Corgi and will do the work (I know the Netaheat's the Widowmaker!), but he's not familiar with this boiler (being more used to modern top of the range German kit). Any suggestions (it's cccold in here!)? Cheers, John

 

[ChrisR]

Not the thermostat if it's trying to light.
Can think of about 5 things it could be.
Gas valve most likely though

 

[gas4you]

If the spark is definately there all the time then stat, fan, aps and pcb sound ok.

Could be crud in the pilot injector, or as you say the gas valve knackered.

If the spark is not 100% all the time, then get him to check the spark earth plate (or whatever the proper name is) as these tend to burn away over time so the spar has nowhere to jump to.

 

[cozzmic]

Do you think it might be down to lack of servicing, 5 years ish is a very long time in boiler terms for getting a service. Once a year to give you peice of mind and probably not have this problem. Boiler that age I would check the flue very carefully too for perforation between the flue and air intake.

 

[stardanny]

(I know the Netaheat's the Widowmaker!),

What you mean?

I used to have a Neatheat 10-16 mk1 for 23 years ( my mum and dad house ), service once every years, before I replace it with Baxi solo 2 50pf.

 

[corgiman]

they are positive pressure boilers so if the seals are shot they spill like wotsit

 

[stardanny]

Ah. So I am really glad to get rid of it.

 

[corgiman]

As long as their are cared for they are a wonderfully reliable old beast

rather have one of them on my wall than any of the new shyte we have to fit these days

 

[leew]

This may help you...
I've recently experienced exactly the same symptoms as yours but mines a Netaheat 10-16. Gas valve replaced now the pilot will light up BUT the main burner takes around 3 mins to come on so now I need a new mercury switch as well! Although these parts are now obsolete they are still available from Parts centre, Plumb centre and various online boiler spares websites but at a hefty price. Good luck.

 

[Agile]

The most likely cause is a blocked pilot injector as its sparking but not igniting.

Thats easy enough for a CORGI to check without even opening the case.

Next would be a failed first stage gas valve solenoid. That normally needs a new valve unless you can source a solenoid for the CORGi to fit. Many would not anyway.

Last would be a stuck gas valve plunger although I havenever seen that on a netaheat.

Tony

 

[stardanny]

Should had saved that gas valve before I got rid of it. Heat exchanger was split and leaking and potterton want to charge me £220.00 new!! Decide to replace it with baxi solo 2.

 

[john1000]

Thank you all for your helpful suggestions! It's looking increasingly like the gas control valve (which was made by US company White-Rodgers, now part of Emerson Electric - I've emailed them for any suggestions they might have). To recap: the boiler starts normally on the EP2000 timer, with no delays, on the first spark, and then runs perfectly, heating everything up toastily, runs for up to half an hour, then cuts out and won't come back on automatically or using the manual override on the timer. The spark flashes regularly and there's a clicking noise from the valve. If I wait 30-60 mins for it to cool down and then use the manual override/ constant sttting on the timer, the boiler fires up instantly and again runs for 30 mins, heating everything, before cutting out again and refusing to come back on. It seems to be heat that stops it re-starting - can heat affect the valve like this? I can't find a replacement 907219 valve anywhere (except £230+ on ebay!). Any alternatives to scrapping an otherwise good boiler? What about having the valve repaired? What's inside it - how does it work? Thanks! John

 

[john1000]

Of course, I can enjoy full central heating, nice hot rads and piping hot water etc, if I carry a stopwatch and run back and forth to the boiler every hour on the hour to switch it on manually... (did I mention I'm Scottish?), but it's a bit knackering (it's upstairs) so I'm hoping there's a better long-term solution short of scrapping the boiler...! Cheers, John

 

[Lesley Jones]

We had a similar problem with our Netaheat ealier this year. Boiler would fire up, radiators would get hot and about an hour later everything would be cold. Boiler would come on again when we put the heating on to contstant but again, only for about an hour. We called out the engineer who normally services our boiler and he changed the three way valve which still didnt cure the problem. He investigated further and fitted a new fan - problem solved.

 

[ChrisR]

seems to be heat that stops it re-starting - can heat affect the valve like this?

Common.

GV isn't hard to get but they are £200+