We had a new water heater installed a couple of years ago, but it had a
problem with a gas smell around it, off and on. The installer came back
several times looking for leaks in the gas line and couldn't find any,
but still there was the smell of gas. At one point he adjusted the
thermostat a bit higher so the water would be just a little bit hotter
than previously, and no more gas smell after that adjustment was made.
I never understood how that adjustment would affect the gas smell issue,
but the tank has worked well since then.
I'm suspicious he adjusted the air regulator, not the thermostat. Not
all water heaters have an adjustable shutter, but on those that do, a
bad air adjustment can cause incomplete combustion, resulting in a
The thermostat doesn't affect the flame at all - all it does is turn
the fire on and off depending on water temperature.
Remember old cars with choke? Cold engine uses more gasoline. Same idea.
NG when burning normally flame tips look blue in color. Yellowish color
means poor combustion due to lack of fresh air or too much gas. In the
case of car you can smell gasoline or black smoke(unburned gasoline) out
of tail pipe. Also gas pressure feeding water heater or furnace have to
be correct. Your gas meter has a pressure regulator. Your gas BBQ has a
pressure regulator, etc. My house is built on R2000 specs back then. If
I don't bring in outside fresh air, furnace and water heater will be
starving for combustion air causing danger of CO level rising indoor.
Well, at least it's a home repair topic! LOL Maybe someone with more
experience than the guy who installed our water heater has heard of this
I haven't touched the thermostat because I'm afraid if I change it,
it'll start having that gas smell again.
How "hard" is your domestic water supply?
The "textbook" recommendations include:
- replacing the sacrificial anode (it "corrodes", bt design)
- draining the tank (mineral accumulations)
- "testing" the high temperature/pressure relief valve
But, almost all of these can find folks with associated
It's not possible to replace the anode in ours with a "stock"
anode (no clearance above the tank to withdraw and insert).
[though I think someone makes a "hinged" anode for this reason]
If the drain valve breaks (some are plastic!) or refuses to
reseal properly (drip, drip, drip), you're faced with replacing
it. You may not be able to find a suitable replacement
(many tanks are glass lined; metal into glass is a big FAIL)
Likewise, testing the TPR valve can leave you with a valve that
no longer closes. In addition to depriving you of future
hot water, you may also end up with *no* water (if there is
not a shutoff on the intake and outtake of the water heater
so you can isolate it from the COLD water supply!)
Bottom line: don't do any of these the day before you have
house guests scheduled to arrive!
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