I made the rather large mistake of fixing my sister's boiler some months ago, whilst I am a plumber I am not a boiler engineer or CORGI registered, and of course I am expected to do the work for free !
Anyway, this Halstead boiler was serviced by a CORGI chap a while ago. Afterwards the boiler started to leak, from the air vent, so I stripped down the boiler to get to the air vent and replaced 2 O rings.
After this new tenants moved in and the boiler overheat cutoff kept tripping. Feeling guilty that I must have knocked something whilst stripping it I went back to have another look. I replaced the overheat lockout switch and the overrun thermostat, just to be certain, but the problem continued. Anyway ends up the tenants were switching the boiler on and off when they required hot water. Not sure where they got this idea from but at least it explained the over heating.
I explained this to them (they did wonder why the heating was not on) and everything seemed oK for a few weeks, but now the ignition lockout has started turning the boiler off. Although I have not studied it for hours at a time it seems to occur after there has been DHW demand and then quickly, but not immediately, there is a CH demand. The boiler does fire up but then the ignition lockout occurs (with a popping sound).
I opened up the boiler (removing the sealed chamber front panel) to examine the flame detection electrode. The electrode should be held on with a plate and screw but I can not tell if this is the case as the whole end of the electrode is covered in a red mastik but the gap between the end of the electrode and the burner is around 2-3mm. Anyway, annoyingly, with the cover off I can not get the problem to occur again.
What I was hoping one of you boiler engineers might know is:
1) Does the ignition lockout occur for any other reason ?
2) Is there some obscure thing the tenants could be doing to cause this ?
3) Where should I start with trying to fix this ?
Any advice you can offer would be much appreciated. I realise this is an old boiler and one option would be to replace it, and this is something that will be done in the future as part of a renovation of the house, but in the meantime I would like to dispell my guilt.
Chris
Anyway, this Halstead boiler was serviced by a CORGI chap a while ago. Afterwards the boiler started to leak, from the air vent, so I stripped down the boiler to get to the air vent and replaced 2 O rings.
After this new tenants moved in and the boiler overheat cutoff kept tripping. Feeling guilty that I must have knocked something whilst stripping it I went back to have another look. I replaced the overheat lockout switch and the overrun thermostat, just to be certain, but the problem continued. Anyway ends up the tenants were switching the boiler on and off when they required hot water. Not sure where they got this idea from but at least it explained the over heating.
I explained this to them (they did wonder why the heating was not on) and everything seemed oK for a few weeks, but now the ignition lockout has started turning the boiler off. Although I have not studied it for hours at a time it seems to occur after there has been DHW demand and then quickly, but not immediately, there is a CH demand. The boiler does fire up but then the ignition lockout occurs (with a popping sound).
I opened up the boiler (removing the sealed chamber front panel) to examine the flame detection electrode. The electrode should be held on with a plate and screw but I can not tell if this is the case as the whole end of the electrode is covered in a red mastik but the gap between the end of the electrode and the burner is around 2-3mm. Anyway, annoyingly, with the cover off I can not get the problem to occur again.
What I was hoping one of you boiler engineers might know is:
1) Does the ignition lockout occur for any other reason ?
2) Is there some obscure thing the tenants could be doing to cause this ?
3) Where should I start with trying to fix this ?
Any advice you can offer would be much appreciated. I realise this is an old boiler and one option would be to replace it, and this is something that will be done in the future as part of a renovation of the house, but in the meantime I would like to dispell my guilt.
Chris