pilot light wont stay lit


Old 01-28-04, 07:32 AM
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pilot light wont stay lit

The pilot light goes out after a few hours of being lit. Furnace will cycle for just a few hours. Already replaced the thermal couple. Older furnace. What else could it possibly be? Dash11
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Old 01-28-04, 07:51 AM
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Like other post here . try and clean out the pilot light itself. Tap on it when it is lit. Blow up in and around the venturi there at the pilot need a good clean flame on the T/C ED
Old 01-28-04, 01:57 PM
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If it has one, you might try replacing the thermocouple. The thermocouple is the rod that sticks into the pilot light flame. The heat generates a current that allows gas to flow to the pilot light and burner. It's purpose is to prevent gas flow to the burner if the pilot light isn't burning - and available to ignite the burner,

Thermocouples cost around $8 - $10 and can be replaced in a few minutes.
Old 01-29-04, 05:18 AM
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Unhappy pilot light trouble

I have the same trouble with my pilot light going out. If the thermocouple needs replaced, would I be able to do it? I am single and care for my elderly mother. I really caan't afford a repairman right now. Thanks for any help
Old 01-29-04, 06:02 AM
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You will be able to change this out yourself.

Go get one at any home centers like Home Depot, or hardware store. If you need help the sales person may be able to help you if you are unclear how to do it.

Take your old one w/ you to get the right lenth.

Turn off the gas and power to the furnace, Take a small wrench and remove the small/thin copper like tube on the gas valve that goes to the pilot assembly.

You should be able to pull the thermocouple out of the pilot assembly.

Then replace with your new one, and rehook it to the gas vale.

Turn gas on, and re-lite the pilot. then turn on the power.
Old 01-29-04, 06:34 AM
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Bless you! As soon as I get Mom dressed good and warm, I'm heading to Home Depot. Thank you so much!
Old 01-29-04, 11:02 AM
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well you stated that you have allready replaced the t/c. there are 4 other thngs that could be your problem

1.faulty thermostat doesn't seem likely but it could be

2. gas valve. saftey devices could be making the valve shut off

3.cracked heat exchanger. this could happen when the heatexchanger heats up and the cracks than blow air out onto the flame

4. leaky flue . you could have air coming in through the flue which is tha in turn blowing the pilot out

good luck and when was the last time you had this thing inspected
Old 01-29-04, 10:37 PM
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pilot light wont stay lit

The problem could be that the pilot flame is not big enough to generate enough current to keep the gas valve open.
An idea off whether the flame is big enough is the time it takes to lock in.
if you have to hold the button down for more than 15-25 secs it probably means you need to take the pilot assembly apart and clean it. I find replacing the pilot spud better than trying to clean them. There should be an adjustment on the gas valve to allow pilot flame increse.
Incases like this I would take a meter reading of the T/C output. But in your case is the end 10mm of the t/c getting a dull red?
Another problem is that some times the main flame shutting down will take the pilot out as it shuts off. suggest you watch the pilot as the main flame shuts down and observe whether the pilot is stable under this codition.
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