Intertherm furnace fan will not turn off. - Intertherm P3RA-048K Air Conditioner

SOURCE: ruud air to air heatpump

Make sure fan relay is wired correctly (G) wire. Ensure the fan on therm is not on, it should be on Auto or off.

If your furnace is short cycling because it has to keep heating your home, the delay in the control board may be staying on to compensate for the exchangers getting hot. If it heats normally, then put your attention to your thermostat.

Set the heating system on aux heat only. Fan should not be on, if it does stay on after a heating cycle, see if the furnace is heating normally, and reaching temp as desired before the heat comes off. Then check the therm wiring, pull the face of the therm, disconnect green wire (fan) and try the heating again.

Robert Moller

• 1524 Answers
• Posted on Apr 23, 2009

SOURCE: Intertherm model MGHA-090-AAPQ -- combustion air keeps running

Sounds like a problem with the circuit board.

dj_relly999

• 4070 Answers
• Posted on Sep 15, 2010

SOURCE: Outside unit will not turn

Hi! You may want to start on having the power supply checked. Good cause why the unit won't power up. Have the compressor checked too just to be sure.

SOURCE: intertherm furnace M1BG wont fire

Make sure the gas valve is turned to the ON position after you had it in PILOT position. Also check the thermostat low voltage wiring @ furnace...jumper the Red & White wires to bypass the thermostat temporarily. Make sure there is 24 volts on you low voltage circuit.