For gas fired hot water heater, my manual states when lighting the pilot,
the red push button should be held down for one minute. Yesterday with the
pilot off and thermocouple and tank cold, I held down the button for only
couple of seconds because my finger slipped but the pilot stays on - strange
as usually pilot should go off. Have you seen anything like this before? Has
the failed safe circuit not failed safe? What should I check or replace?

Can you reproduce this?? If so, then you might have a problem.
Therocouples are easy to replace -- just screw-in.

Can you reproduce this?? If so, then you might have a problem.
Therocouples are easy to replace -- just screw-in.

"professorpaul" wrote in message
oups.com...
Can you reproduce this?? If so, then you might have a problem.
Therocouples are easy to replace -- just screw-in.


I'll try to reproduce this again. Don't think its the thermocouple as it
won't give a voltage when its cold. I think its the circuit in the control
box or a valve stuck open for the pilot, no?

# Fred # wrote:
"professorpaul" wrote in message
oups.com...
Can you reproduce this?? If so, then you might have a problem.
Therocouples are easy to replace -- just screw-in.


I'll try to reproduce this again. Don't think its the thermocouple as it
won't give a voltage when its cold. I think its the circuit in the control
box or a valve stuck open for the pilot, no?


can you lite the pilot without pressing the button?

# Fred # wrote:
For gas fired hot water heater, my manual states when lighting the pilot,
the red push button should be held down for one minute. Yesterday with the
pilot off and thermocouple and tank cold, I held down the button for only
couple of seconds because my finger slipped but the pilot stays on - strange
as usually pilot should go off. Have you seen anything like this before? Has
the failed safe circuit not failed safe? What should I check or replace?



After the pilot has been lit normally, simply unscrew the
small nut which attaches the T/C cable to the gas valve.
If the pilot (and main flame) immediately goes out,
the valve is working correctly.

Some modern T/C's heat up very rapidly and can produce
enough holding current for the electromagnet to stay in
after the pilot flame has been on for only a few seconds.

Jim

Thanks to all and great troubleshooting ideas about lighting the pilot
without pushing the button and removing the T/C nut to the valve.