Slight natural gas smell

[jjrr4808]

23 year old State 40 gal natural gas fired water heater that has it’s first problem.

The pilot light is not staying lit. It relights while depressing the gas control valve knob but after a minute, when I stop depressing the knob, the pilot does not stay lit, so the thermocouple is the first suspect.

But while depressing the gas control valve knob trying to relight, there is also a slight release of gas rising from around that knob.

Not sure if the problem is the thermocouple, the gas control valve or the pilot light gas tubing. The pilot flame looks normal and the thermocouple appears to be in the correct position but both have a little bit of white discoloration.

Thoughts anyone?

[Larry Weingarten]

Hello: There could be a gas leak from where the pilot tube hooks up to the gas control, or where the bigger main burner gas line hooks up, or possibly from the seal at the control knob itself. I’d check the screwed fittings under the gas control with some spray soap like Windex. If you’re lucky, the leak will show up there and should be easily fixable. The other possibility of a leakage point is in the pilot tube, down by the pilot light itself, where things screw together.

Use soap, or better a gas sniffer to find the leak. Using a match might work and it might send you to the hospital… not your choice 😯

If the gas control itself is leaking steadily, your choices are to replace the control or entire heater. It’s better to find a leak at a fitting 😉 The thermocouple can not be the cause of the gas leak as it is not connected to gas. It may be a problem though if the pilot flame is not hitting it sufficiently.

Yours, Larry

[jjrr4808]

Thanks so much. On an older unit like this, it correct that control knobs should be able to be removed and the seal replaced?

[Larry Weingarten]

Hello: I don’t think so. Even older controls all use screws designed to keep inquisitive people out and I don’t know where that seal could be purchased. Maybe you should have a look at the anode in the tank and see if there is anything left. If so, spend money on keeping the heater going. If not, be thinking about a new unit.

Yours, Larry

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