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View Full Version : Furnace turns on but blower does not.


mannyburgos
Jan 6, 2008, 12:41 PM
Hello my nordyne mmha-077aahr-01 gas furnace turns on but the blower doesn't. The furnace motor turns on for about 30 seconds then turns off then turns on again for 30 more seconds then turns off and this continues to happen for about 3 minutes and then the control board blinks a red light three times and nothing comes back on. The only way the blower comes on is if I put the switch to the on position but it won't work on the auto position. I tried putting the thermostat to the fan on position and nothing happens. I tested the voltage at the thermostat between the 120v line and the fan wire and it shows 120v and I tried jumping the wires 120v and the fan wire and nothing happened. I wonder if the problem could be with one of the limit switches. How would I go about testing the limit switch or can you please suggest something for my problem. Thank you manny burgos

hvac1000
Jan 6, 2008, 04:33 PM
Pressure Switch Closed with Inducer On = 3 FLASHES

Check pressure switch.