Nordyne gas heat, flame shuts down

[Johnho]

I have Nordyne model G5RA096C-20, serial # G5R9506-00137. My problem is that in heat mode, flame is (occaisionally) shutting down after a few seconds of burn. Sometimes remains lit on retry, sometimes not. I've checked/cleaned entire vent, removed and cleaned venturi(s), removed and vacuumed at draft inducer and entry of heat exchanger. None of flame sensors or limit sw needed to be reset. I have noticed that with cabinet door open and lockout switch defeated, always seems to work fine. Is it likely that inducer motor is 'starving' for fresh air? Ctrl panel giving 4 blinks, ignition failure, but it does actually light with a god blue flame, then shuts down as the main blower turns on. I also read suggestion to clean flame sensor with steel wool.
Any help you can give greatly appreciated.
JH

[Robert]

Hi,

Most common for ignition failure is bad flame sensor, ignitor or gas valve.

Most common is a dirty flame sensor.

Check the shroud for cracks and clean rod good with steel wool.


Also see if ignitor is receiving 120vac at plug connector and keeping it while glowing for about 30 seconds.



Thanks,
Robert

[Johnho]

Thanks Robert. Ignitor seems to be doing its thing...glows and ignites the gas, remains that way for a little bit afte flame is present. I'll try cleaning the sensor.
Think it's just coincidence that seems to work properly with the cabinet door open?

[Robert]

Can be more than one problem, combustion motor may not be running to correct rpm.

Once the ignition issue is resolved, may get another code flash.


Thanks,
Robert