Our Nordyne gas furnace M7TL 045A BWT blower comes on keeps blowing but No flame.the lights are solid green and red. We cleaned sensor..nothing

SOURCE: Goodman Heater Blower Not Coming ON

The Ignitor on my furnace glows and fades. I do not hear anything blowing either as I watch the ignitor get bright orange..then fades.

Any answers? I tried to look here on this site but have not seen anywhere where there is a solution. I was going to replace the entire gas valve assembly because I am guessing the problem is with the coils sicne the ignitor fades away.

Help please?

SOURCE: Rheem gas furnace pilot lights, but no burners or fan

If the burners do not fully ignite, the sensor will shut the furnace down. The lack of sufficient burner flame is a gas valve or gas pressure problem within the valve.
Replacing the gas valve with the original one may get you going. I surely suggest a professional service company for safety reasons and a thorough inspection. A 20 year old furnace is past it's normal life span.

Allen Neal

• 359 Answers
• Posted on Jan 12, 2009

SOURCE: wiring NO, NC relay on Nordyne furnace

NORDYNE , GOODMAN, AND NUTONE ARE ALL BUILT BY SAME MFG SO IF YOU TRY ALL THESE MAYBE YOU CAN FIND THE HELP YOU NEED

SOURCE: weak flame in intertherm furnace

Ok, so we can rule out the ignitor. (standing pilot systems can develop problems that will cause such symptoms.)

Check the gas pressure, make sure you are getting 11 to 14 PSI.

You need that after the regulator all the way to the manifold.

Also check for cracks in the heat exchanger, causing the wind from the blower to distort the flame pattern enough to cause improper contact with the flame sensor.

Make sure the burners and flame channels are clean of rust, and dibri build up, allowing the flame to properly contact the sensors.

SOURCE: FURNACE COMES ON AND SHUTS DOWN WITHIN 15 SECONDS

On a call for heat, the 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.

What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control). When all else fails, check the ground connection for corrosion.