Funny hot water heater thermocouple circuit


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

can you lite the pilot without pressing the button?
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# Fred # wrote:

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