Twice tonight, I've had to restart the pilot light on my gas water
heater. It always starts right back up, and heats the water up just
fine. But this is twice now that I've had to do it. I also have a gas
boiler (with a pilot light) and a gas stove (ignitors, no pilot light),
and these two items seem to be functioning normally. The water heater
is an "A.O. Smith Promax" and the only date I can find on it is
"11/03", but I can't tell if that is installation date or a service
date. It *looks* fairly new (i.e., within the last 5 years) but I
don't really know how to tell.
What should I do?
If your water heater has a standing pilot it also has a thermocouple
that controls the gas flow. If the thermocouple isn't hot, it will
turn off the gas flow so a blown out pilot doesn't cause the house to
fill with gas. These thermocouples routinely go bad after a few
years. So that's one possibility.
Another possibility with water heaters is tank failure, and a slow
leak or condensation or something causing water to drip on the pilot.
Those are probably the two biggest causes I'm aware of for pilot
failure. Thermocouples are pretty easy to change and available at
hardware stores. Measure the length of the thermocouple that you
have and that should lead you to a decent replacement. If you're not
comfy with this, get a pro in to check what's going on, or if it's
been 10 years, just replace the water heater--it's probably due.
Also, since it appears to be an 03 tank, if it is the thermocouple, get
the serial # and give the manufacturer a call, as it's likely under
warranty. When I did that with my Reliance WH, they sent me a new one
for free in 2 days.
I may have to do that. I know that thermocouples aren't horrendously
expensive, but I don't have a clue as to how to get at it in the water
heater. From the little pilot light inspection window it appears to be
on the backside of the unit, but there is no access panel anywhere on
I had a feeling it was the thermocouple (last year our gas boiler was
serviced, and I asked lots of questions about how gas appliances work,
Something else I'm noting- Lately the part of the house that has all
the gas appliances (it's a small 900 sqft house) has had a very faint
smell of gas in the air. So very faint, but I'm so paranoid about
these things that I can always smell it. ;)
My guess is that the water heater pilot light goes out for whatever
reason, but it takes the thermocouple something like 10 or 15 seconds
to cool down to the point where it actually shuts the gas off. Thus
releasing a small but barely detectable amount of gas into the place.
Sound reasonable? If you call the gas company, won't they come out
with a more sophisticated device than my nose and 'sniff' around the
place to find any potential leaks, even if they're very small?
While you're waiting for the pro, I hope you have already taken a spray
bottle filled with water and a small amount of dish washing liquid and
sprayed every joint of every gas pipe you can access. Look for bubbles.
Paul in San Francisco
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