Jeff wrote:
I have not been able to keep my water heater pilot lit since I turned
on my AC. It might stay on for a day at most. The plumber suspected
downdraft. The Chimney sweep found nothing. When the heater is
heating water there is a powerful updraft through the chimney.

The sweep said I should have the thermostat replaced. I can light it
ok, so it must work somewhat. A previous poster suggested taking off
the gas lines from the valve and blowing them out, maybe that is next?

Jeff

I agree with Ed on this one. I will add that you did miss one thing
that might be part of the problem. You may want to try replacing out the
thermocouple. I wonder if you get some cold air in the area of the WH when
it is on? If the thermocouple is weak it could be the problem.

I once had a problem with a WH that no one could figure out.
Thermocouple was replaced several times, venting triple checked finally they
replaced the whole heater and no more problems. I never will know what was
the problem.

--
Joseph Meehan

Dia duit