Stimus
Jan 6, 2010, 12:10 PM
Hello,
I have a Heil SP80 natural gas induced draft fan furnace, model # NUG5075BFB2. The unit fires up normally and all is well until the unit shuts off when the temperature setpoint is reached.
The draft inducer motor then cycles on and off shortly after the flame is shut down and for 20 or more cycles at a pattern of 3-4 seconds between the motor on and off states. This continues during and after the main blower timed cool down operation.
I hear a series of clicks in the pressure switch and pinching the vacuum line shut has no effect on the cycling. What should I look for?
Thanks!
Bill
I have a Heil SP80 natural gas induced draft fan furnace, model # NUG5075BFB2. The unit fires up normally and all is well until the unit shuts off when the temperature setpoint is reached.
The draft inducer motor then cycles on and off shortly after the flame is shut down and for 20 or more cycles at a pattern of 3-4 seconds between the motor on and off states. This continues during and after the main blower timed cool down operation.
I hear a series of clicks in the pressure switch and pinching the vacuum line shut has no effect on the cycling. What should I look for?
Thanks!
Bill