Nordyne M1BB 086A BW failed ignition

[rob143]

I have an M1BB 086A BW that is going thru startup sequence all the way to the point of not actually igniting. After several failed attempts it shuts down and I get 3 blinks from the control module 626-4210.

In attempting to troubleshoot this in hopes it was the much less expensive ignitor (part# 902661A) I found 80.7 ohms across the ignitor, and 120VAC after the purge cycle completes.

To me this means the control module and centrifugal switch are ok or I wouldn't get 120VAC across those points. I reconnected the ignitor connector and with the room lights off attempted ignition again. I can see light produced by the ignitor when it is called for.

Am I incorrect in thinking it has to be a faulty gas valve (part# 624610)? If so how do I check the valve for correct pressures as mentioned in other posts? I'd really rather not go swapping $125 parts like that valve just to eliminate it as the possible problem. Process of elimination parts swapping has never made sense to me, and I'd like to avoid it now. If this is something I can't check, but seems to be the only logical reason for this problem, I'll then gladly replace the valve.

If I'm missing something in my thinking....what is it?

Thanks for any help. Running 2 little ceramic heaters is working for now, but winter is here and they won't get it done much longer.

[Robert]

It needs to be checked by a Tech to see if the gas valve is operational and if it is getting correct pressure.

Is the gas valve receiving 24-28VAC ?



Thanks,
Robert

[rob143]

The gas valve is receiving 26.5VAC.

It sent 26.5VAC to the gas valve for several seconds after the ignitor warmed up and then opened presumably upon detection of no flame.

This is just one more step that the control module appears to be doing correctly, and more reason to suspect it has to be a faulty gas valve.

[Robert]

Could be clogged burner, burner orifice, low gas pressure,,,,,,,,ALL could do same as well as the GV.



Thanks,
Robert