Gloworm Fuelsaver II problem

[PE]

Hi
Currently under a BG Homecare agreement and had a number of call outs over past month trying to get to bottom of problem

Basically we have a very old boiler (probably 20 years?) so I am aware it doesn't owe us anything, but we may be moving next year and so ideally just want it to last this winter so we can then decide what to do as far as replacing (ie cheaper model if moving or top f range one if staying)

It is a conventional boiler that deals with hot water and central heating for 10 radiators (some large ones) spread over a 4 bed house. We have electric shower

The problem seems to be that the pilot keeps going out at various intervals, ususally apparently when the system isn't on (although could be going out when turning on or off I guess). The pilot can usually be relit OK by me

The first coupd of visits basically entailed the usual replacing of thermocouple and I believe "igniter". Recently they have now also replaced the gas valve and this week they replaced a couple more parts (which I do not know until I get home later for paperwork) which they said were the last parts they could replace on it

The guy has said that he thinks it could be limescale and potentially the heat exchanger which apparently isn't the easiest to change and nor is it covered by our agreement

My plan is to get a second opinion (of course) by local Corgi but any opinions what could be making the pilot keep extinguishing?
The BG man said it could possibly be the wind coming in via the flue blowing out the pilot?

Any assistance appreciated and any recommendations for new boilers also appreciated - have researched that Worcester appear pretty OK and more top end maybe Viessman?

Thanks guys

 

[PE]

Ok the bits replaced were more ignition parts by the looks of things - pilot burner and pilot injector aswell as a new ignition lead

Problem still remains - I have relit twice today and saw the flame go out after about 30 minutes or so of being alight and burning well. Almost seemed to overheat and shut down?

Any opinions gratefully received thanks before I call local Corgi guy

 

[geoff@cetltd]

Well, the standard answer would be pump or blockage problems causing the heat exchanger to overheat, but the fuelsaver suffers from a fairly unique problem that the fan windings overheat. There is a resettable thermal trip inside the windings of some fuelsavers which will let the fan come on for some minutes, overheat, stop, cool down and come on again

So, first see what the fan is doing before looking elsewhere
Of course, most CORGIs are unaware of this, so it would confuse them

 

[PE]

Well, the standard answer would be pump or blockage problems causing the heat exchanger to overheat, but the fuelsaver suffers from a fairly unique problem that the fan windings overheat. There is a resettable thermal trip inside the windings of some fuelsavers which will let the fan come on for some minutes, overheat, stop, cool down and come on again

So, first see what the fan is doing before looking elsewhere
Of course, most CORGIs are unaware of this, so it would confuse them

Thanks

Would that actually cause the pilot to go out and need relighting each time it shuts down?

Cheers for the input

 

[pannierstan]

PE you didnt mention if its a Balanced flue or Fan flue or did I miss it

 

[andsam]

Is the boiler stat working correctly ?

I would turn the stat down low, Leave on hot water only and watch it.
Does the stat correspond with temp of pipes leaving the boiler.

When the clock is turned off after use does the pump continue to run for a short period of time.
( pump over-run )

andsam

 

[PE]

PE you didnt mention if its a Balanced flue or Fan flue or did I miss it

excuse my ignorance but how do I find this out - thanks

 

[PE]

Is the boiler stat working correctly ?

I would turn the stat down low, Leave on hot water only and watch it.
Does the stat correspond with temp of pipes leaving the boiler.

When the clock is turned off after use does the pump continue to run for a short period of time.
( pump over-run )

andsam

Hi do you mean the thernostat that controls the heating (ie the one on the wall in the hall) or is there another one on the boiler itself?

Don't think the pump overruns no - seems to shut down pretty much as clock turns off

Thanks

 

[andsam]

The stat on the boiler.

If the heating system is hot and the clock turns off the boiler should keep the pump running for a period of time if not the boiler cut over heat and cut the pilot.

The pump over run is incorperated in the boiler thermostat I think.

Andsam

 

[PE]

The stat on the boiler.

If the heating system is hot and the clock turns off the boiler should keep the pump running for a period of time if not the boiler cut over heat and cut the pilot.

The pump over run is incorperated in the boiler thermostat I think.

Andsam

Thanks will check this out

 

[chrishutt]

I have relit twice today and saw the flame go out after about 30 minutes or so of being alight and burning well. Almost seemed to overheat and shut down?

This boiler has an overheat stat on the heat exchanger which is part of the thermocouple - FFD circuit. Any overheat would cause the pilot light to go out and the boiler shut down. Any competent gas engineer (i.e. not BG) would be able to test if that were the problem.