Gas boiler failing to light pilot light

libra10

Our Baxi Solo gas boiler has just started making clicking noises and failing to light the pilot light. It will click quite a few times, sometimes it works, sometimes it doesn't. Seems to be doing it more recently.


OH thinks this may be the ignitor or possibly needs cleaning.

Any ideas please?

Andybez38

when the pilot light fails to light, it usually is a thermocouple fault. It is a cheap repair you can do yourself.

sparklymessygirl

When our boiler fails to light I take the front panel off and hoover the dust and then it usuall works ok

Sparkly

libra10

Thanks everyone for quick replies. We will try hoovering out the dust behind the panel. If the problem lies with the thermocouple, can you advise how you would know this is the problem and how we could repair.

Thanks a million

whitebeams

Have you checked there is a gas supply to the boiler? And if there is can you see a pilot flame ignite but not stay lit?

libra10

Pretty certain there is a gas supply to the boiler, there always has been.
The pilot light is failing to light all the time now and we have resorted to using the electric immersion heater for hot water. Luckily it's a little bit warmer now and we don't need to use heating. Looks like we will have to call out a heating engineer.

Thanks very much everyone for your replies

moneysavingplumber

You shouldn't remove the combustion chamber cover on a room-sealed boiler unless you are qualified and competent to work on gas appliances. Removing the outer case and hoovering won't make any difference as the chamber is sealed with the inner case, but you might burn yourself if it's running! The integrity of the inner case seal, which is a safety feature, will need to be verified once it has been removed, before refitting and recommissioning. Gaining access to the combustion chambers on Solos is not as straightforward as simply removing a cover on any of them (MKs 1,2 or 3).

The Baxi Solo usually only has an intermittent pilot, which means it is only lit when the burner is about to light. There is no thermocouple on this version, it will spark until the flame is sensed. If it sparks for a long time and gas is passing through the pilot burner causing an eventual explosive ignition, it usually means the spark electrode or lead is worn out, or the insulating sleeve may have worn causing the spark to arc with part of the boiler casing rather than sparking at the electrode. If it is not igniting because no gas is getting through, it could be a faulty solenoid or sticking valve, or a blocked pilot injector. There is always the possibility it is the PCB, although they don't often fail on Solos. A good professional will be able to check whether the pilot tube or injector is blocked.

If you can see a spark through the viewing window in the correct place then it is likely the pilot is blocked or the gas valve isn't opening. If you cannot see a spark and can smell gas outside the flue then it is a faulty electrode as described above and should be turned off until it is sorted.

Definitely a job for a professional.

libra10

Thanks very much moneysavingplumber. Your comments and advice are really helpful. First thing after the Easter holidays we will phone and book a service.

Happy Easter everyone, and thanks very much for your help