Baxi Bemuda 552 Thermocouple replaced but still no Pilot Light!

[IAN CAPEL]

Gas valve

[Chrisk]

I have a Baxi Bemuda 552 which is about as old as Noah's Ark itself.

couple of months ago the pilot light went out for no reason. Relit i again and it stayed on with no problems until last week when it wen out again. This time the pilot won't remain lit. I've replaced the thermocoupl and cleaned the pilot jet out. But the pilot STILL won't remain lit!!

Any ideas PLEEEEEEEEEEEASE!

-- Chrisk

[Ed Sirett]

Check the obvious first.

Nice flame that heat the last 10mm of probe? Connection to gas valve secure? Check t/couple should be about 25mV when hot.

All the above OK then maybe the gas valve.

with experience you can often 'feel' the gas valve and determine whether the t/couple is OK but not quite doing enough or there is absolutly nothing available. This can help track down whcih sort of problem you have.

Replacement gas valve should be less than 100, however you better know what you are doing.

It's (nominally) warmer weather now so may be time to give the old beast the last rites?

[Guy King]

The message from Chrisk contains these words:

No, which is a right rip-off. On most models of readily available gas valve the pilot safety valve is held open by a solenoid. Once the solenoid's died you have to replace the whole valve, despite the solenoid being a simple item held in IIRC by one screw.

[Chrisk]

Won't a valve just fail once though? It was fine after relighting th

pilot when it went out for the first time a few months ago :)

Are valves servicable? I suspect not...:(

Anyone know roughly what the cost would be to replace??

Chrisk Wrote:

-- Chrisk

[Chrisk]

Hi Ed, many thanks for the thorough reply. The flame nicely engulfs 90

of the probe after i cleaned the jet.

Do you mean that you should be able to 'feel' the operation of th valve whilst preheating the thermocouple?

I've also heard from somebody that it's not uncommon for thermocouple to be faulty off the shelf....has anyone had experience of this???

I wouldn't normally be worried about the heating as the weathe (apparently) is geting hotter...but the problem is that I'm selling th house and need to get it working before and offer/survey is done. can't justify forking out for a new boiler if i'm moving away!!

Ed Sirett Wrote:

[Ed Sirett]

As you begin to release the pilot valve you can often feel if the valve is half-holding on and then drops out as slowly release the pressure on the button. If this is the case then some t/couple current is flowing and most of the faults can be eliminated. In fact the the t/couple is either not warmed up enough or it's not working well enough.

The other way is to measure the voltage form the t/couple 25mV+ will be OK.

Not often. but it did happen to me once.