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