basic thermocouple test?

[keelstow]

I am having trouble keeping a pilot light on to a gas boiler. It sparks up OK but goes out once I release the control knob.

I have pulled the thermocouple and heated its end on gas cooker to the level of heat the pilot light would produce.

A multimeter connected to each end of the TC only produces 8mV as opposed to the 13-25mV spec value.

Am I carrying out the test properly and why has it suddenly given up the ghost. It is 10 year old to be fair. Is there any way to use the boiler without a working thermocouple whilst readily available spares are found.

thanks for any advice and suggestions

[mike]

"keelstow" wrote in news: [e-mail]:

Thermocouples fail; it's prudent to have a a spare, just as you would a fluorescent light starter.

It's been sitting in a flame for ten years - how would you like it?

I expect you could fake it; where do you live? (I don't want to be near your gas explosion!

mike

[Andrew Gabriel]

They do wear out. 10 years is good going. It could also be a dirty pilot jet, which isn't sending the flame in the right direction. That in itself could be a sign the boiler and/or flue needs cleaning out, and might be generating soot and CO. Particularly in the case of an open flued boiler, this must be checked for before it goes back into service.

No, you can't operate the boiler without one. You can pick up universal ones from places like B&Q, Wickes.

[keelstow]

took your advice Andrew and got one from wickes.

boiler now working as normal after easy instillation. I guess substitution is the way to locate the faulty part.

Glad I visited this group as I was'nt aware parts were so easily available. Otherwise would be sitting in a cold house with no hot water!

cheers

martin

[Dave Plowman (News)]

Generic ones are available from the sheds and are so cheap it's not really worth testing the old one except by substitution.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "keelstow" saying something like:

They just do. Thermal wear'n tear, I suppose.

It's a safety device, ferchrissakes.