Furnace troubles - resend

[Philip J Jones]

Sorry if this message is here twice..

Does anyone know where to get basic troubleshooting info on furnaces (the
type that sit in your basement and hreat your house)?

With the big chill hitting Ohio today, I have discovered that mine is
cycling rather than staying on, and thus cannot maintain the correct set
temperature. The igniter comes on and ignites the gas, then after 2 mins it
abruptly turns off. A minute later it ignites the gas again, and the cycle
repeats. My system is a Rheem 80 Plus. Obviously, some sensor (or the
control PCB) is not behaving, and thus the control system is turning it off.
My system has a sensor in the flame, which is a not a temperature sensor,
but rather the conductivity through the flame to the (grounded) metal gas
burners is monitored. I have removed and cleaned the sensor, but to no
avail.

Any clues?

Thanks,

Phil

[Michael Machajewski]

As mentioned in previous posting, Check the flue to make sure there is no
blockage. I had a similar problem with my bryant furnace a few years back and
found a dead bird partially blocking the flue. I installed a chimmney topper
soon thereafter to prevent futher occurances.

Mike Mach