Halstead Quattro

[TheInevitable]

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

 

[Gasguru]

Since you are a plumber you are fully aware of the legal position regarding boiler repairs. The tenants deserve someone suitably qualified to repair the boiler. Who carried out the LGSR?

 

[Mcfly1]

The inevitable- Im working on the same boiler, where is the overheat cutoff switch on this boiler?

 

[TheInevitable]

Hi the switch is located on the left hand side of the combustion chamber, on the second loop of the main heat exchanger (towards the back of the boiler). Originally the boiler had a pole that stuck out the top which allowed the reset button to be pressed from outside the boiler but these often fell off and so you have to open the boiler to get to the reset button.

 

[Agile]

As you are not CORGI registered I dont think that you should be tampering with combustion related aspects of the boiler.

As its a tenanted property there is a serious risk to the tenants if you got anything wrong.

Presumably your sister does not bother to get a Gas Safety Certificate as required by law?

Tony

 

[TheInevitable]

Thanks GasGuru and Agile. I wasn't aware of the landlord gas safety record, I guess that's the point about me not fixing boilers or renting out houses !

Having spoken to my sister she already knew about the requirement. That was the purpose of the visit by the Corgi chap recently. She has booked him to return and retest the boiler. She'd assumed that as a plumber I was allowed to work on the boiler without invalidating the safety record.

The Corgi guy will attempt to fix the boiler and then carry out the retest.

I would still be interested in suggestions for fixing the problem, if it is worth me getting a new electrode or something before he arrives and hence speed up the turn around time for fixing the boiler.

Cheers