| Well since you tried that and the pilot stays lit, try watching the flame when you have it going to see if it slowly gets smaller and smaller like it's running out of propane. If not and it just suddenly shuts off, then I'd say there's a problem in the heater gas valve. If it slowly shuts off, then get it relit and the main burner going again. Then lite a burner on the cookstove to see if it slowly goes out when the heater flame goes out. If this happens then I'd guess there is a problem in the propane regulator at the tanks. If the stove burner doesn't slowly go out then check the copper tube that feeds propane to the water heater from the main black pipe line.
Is this water heater equipped w/ electronic control board or just the old thermocouple controlled gas valve?
I'm sure the propane tanks have the new style valves. Try switching tanks. Sometimes those valves can be a PITA causing the symptoms you describe.
HTH,
Mike |