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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a nordyne furnace and I have already changed a few

Customer Question

i have a nordyne furnace and I have already changed a few parts. Originally i was told that the limit switch was bad so i changed that red light was flashing once. i have changed the pressure switch, flame sensor, circuit board and draft inducer motor. With the old motor the light will only flash once, once i put the new motor on it flashes twice. What should i do next?
Submitted: 1 year ago.
Category: HVAC
Expert:  Heath.M replied 1 year ago.

Hello my name is ***** ***** will be my pleasure to assist you. I am going to ask a few questions. Right now you get 2 flashes from the led? What does the furnace actually do when you reset the power and turn the heat up for heat?

Customer: replied 1 year ago.
the inducer motor comes on and instantly flashes twice
Expert:  Heath.M replied 1 year ago.

okay lets try this turn the power off to the furnace disconnect the wires to the pressure switch, get an unbent paper clip bent in a " U " shape. we will use this to jump the 2 wires together but we have to do it after the inducer motor has started and the call for heat is recognized. Once the inducer motor starts and is running for a few seconds use the unbent paperclip to jump the 2 wires together by pushing the paperclip into the wire connections.

Customer: replied 1 year ago.
Alright i can do that. What should i expect it to do?
Expert:  Heath.M replied 1 year ago.

once the pressure switch wires are jumped it should send power to the igniter the igniter should glow then the gas valve will click and open sending gas to the burner being ignited by the igniter.

Customer: replied 1 year ago.
Ran for 5 minutes kicked off and the red light flashed once
Expert:  Heath.M replied 1 year ago.

ok that is for one of the limits tripping. you will need a thermometer to check the discharge air from the furnace. a meat thermometer can be used we need to know how hot the air is coming from the furnace. did the main blower come on? you also need to check the chimney for any blockages as the pressure switch is new it should work with the inducer running.

Customer: replied 1 year ago.
i didn't change the limit switch on the inducer motor, could that be it? the main blower did come on
Expert:  Heath.M replied 1 year ago.

if you have a meter you can check the limit by ohming it out to see if the switch is open. it should be closed. or disconnect the wires and jump the switch out and this will tell you if that is the switch that is open. I think you have to reset the power to the furnace once the limit trips to get it to retry.

Customer: replied 1 year ago.
alright so if that switch is closed whats next?
Expert:  Heath.M replied 1 year ago.

there is three other switches there is the rollout the blower deck switch and vent switch one of them has to be tripped. they should be wired in series with a blue wire

Customer: replied 1 year ago.
alright so ive changed the limit switch part #2639885, and ive ordered #(###) ###-####and #(###) ###-####to be here for tomorrow. Those would be the 3 right?
Customer: replied 1 year ago.
those are off by the way
Expert:  Heath.M replied 1 year ago.

yes that would be the parts