Pilot light won’t stay lit

[camel2215]

I have a gas hot water storage tank. The pilot light will only stay lit as long as the button is held in. What could be the problem?

[nicktheplumberParticipant]

This problem is almost always a bad thermocouple sensor…that’s the little cylinder that’s clamped onto the pilot light assembly and is heated by the pilot flame. It sends a signal (either mechanical, via a plunger, or electrical in some models) that tells the regulator that the pilot is on and allows gas to flow to both the pilot and the main burner. It’s a safety feature. In the old days, gas appliances had pilots that were just lit (after opening a mechanical pilot valve), and even if they blew out, the pilot kept emitting gas. Even in these older systems (called “the gas train”), there was a thermoelectrical sensor in the pilot that would shut of the main burner gas if the pilot went out, but the pilot would still emit gas. You still find this system in some older homes. It is inherently less safe than the current design, but surprisingly few explosions occurred, presumably because most of the unburned pilot gas just went up the flue.

Bottom line…spend about $7 and install a new thermocouple, and that should fix the problem. If not, your regulator is shot. If you have any hesitation about your ability to do a safe job, hire a plumber.

[racefanoneParticipant]

Ted: One thing Nick forgot to mention was that the pilot could also be dirty,might as well clean it.The pilot could be weak or lazy and not hitting the thermocouple properly.Just my two cents worth.

» This message has been edited by racefanone on 28 January 2003

[SelgasParticipant]

Well done team I might even hire ya yet!!!!!

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

[TedParticipant]

Many thanks to all of you who replied. We had to replace the thermocouple.

[SelgasParticipant]

Tiss what one would have expected to be the case of all the grief – a simple but effective safety component – they do not last forever ya know!!!!
Not like us old Gasfitters we just keep on keeping on……

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

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