kleinbiker1
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- Nov 28, 2011
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I'm sure this is common and easy for someone who is HVAC knowledgable but it's stumping me.
I have what appears to be an older Rheem. There is no computer nor any electronic controls. Once the stat calls for heat the exhaust fan comes on and a few moments later the gas fires and stays lit just fine. Once everything heats up the blower comes on. The gas will then stay lit for another 10 to 40 seconds where it will suddenly then turn off as well as the ventilation fan. The blower will keep running as the mechanical temp controlled switch mounted in the initial duct keeps it on.
I'm not sure why it's shutting down. I've bypassed the pressure switch that's activated by vacuum created from the exhaust fan so that doesn't seem to be it. The mechanical device that turns on the blower and shuts it off when everything is cool enough appears to work fine. I can see it's dial turning appriopriately with temperature changes.
I know in newer furnaces there is some type of electric thermo couple to make sure the furnce has lit properly and will shut down the gas if it doesn't detect heat in a pre determined amount of time. The only thermocouple I thought I had was the one that keeps the pilot light lit. I thought I would pull the burner out and take a look. I did find what looks like the end of an elecrical thermo couple with no wire attached to it. I can't however find any stray wires that might have gone to it.
I took several picures of the inside of the furnace and what not to hopefully help someone help me....
TIA,
Chris
I have what appears to be an older Rheem. There is no computer nor any electronic controls. Once the stat calls for heat the exhaust fan comes on and a few moments later the gas fires and stays lit just fine. Once everything heats up the blower comes on. The gas will then stay lit for another 10 to 40 seconds where it will suddenly then turn off as well as the ventilation fan. The blower will keep running as the mechanical temp controlled switch mounted in the initial duct keeps it on.
I'm not sure why it's shutting down. I've bypassed the pressure switch that's activated by vacuum created from the exhaust fan so that doesn't seem to be it. The mechanical device that turns on the blower and shuts it off when everything is cool enough appears to work fine. I can see it's dial turning appriopriately with temperature changes.
I know in newer furnaces there is some type of electric thermo couple to make sure the furnce has lit properly and will shut down the gas if it doesn't detect heat in a pre determined amount of time. The only thermocouple I thought I had was the one that keeps the pilot light lit. I thought I would pull the burner out and take a look. I did find what looks like the end of an elecrical thermo couple with no wire attached to it. I can't however find any stray wires that might have gone to it.
I took several picures of the inside of the furnace and what not to hopefully help someone help me....
TIA,
Chris