I have read many different threads regarding similar situations with these furnaces but mine seems a bit different. i have the kg6ra 096c-12b model and when heat is called for the furnace begins its normal process - the ignitor glows, gas valve opens and i get full flame across all burners, BUT within 2-3 seconds the flame is gone [im assuming the gas valve closes]. my first instinct was the flame sensor, which appeared fine but i cleaned it up anyway and tried again. i even replaced it with a new 1 thinking that was sure to be the problem, still no luck. its always the same situation, everything appears to be fine but i lose the flame within seconds.

after it tries to reignite a few times i get the error code of 4 flashes meaning ignition failure [check ground], which is what most people seem to get when they have no ignition at all. a friend of mine owns a heating/cooling business and since this is his very busy time of the year and he knows i can handle most repairs on my own he told me i should replace the ignition module because he believes that to be the issue. i am in no way doubting him, but at the same time he is basically giving me that advice based on the same information i am supplying here, so i was wondering if anyone else had an opinion or better yet had the same experience and what their fix was. if the ignition module cost the same as a common sensor i would have bought it already, but i figured i would get a second opinion, any ideas? thanks in advance

 

Welcome to the forums.

It sounds like you're on the right track with the flame sensor. When the burner ignites.... the flame rod must be in the flame. Sometimes there is a clogged opening in the burner and there is not a proper flame at the sensor rod.

Also, the flame sensor completes a circuit to ground thru the metal burner and to the control module. Check the burner and the control module screws for corrosion and tightness.

 

PJMax provides good advice.

The correct way to evaluate this problem is to put a multimeter in series with the flame sensor and measure the AC microamps that flow when the burner is lit.

Also measure the AC voltage being applied to the wire to the flame sensor when the burner is lit.

You may have a bad circuit board, but replacing it without the additional checking described above and by PJ Max would be a poor practice, especially with such an expensive part.

 

ok thanks for both of your replies, i was away this weekend so i am gonna do some investigative work today on it. two questions i have tho, when measuring the microamps on the flame sensor, what reading should i be getting and also the voltage on the wire?

and would that reading be available from the second the call for heat comes in or only when i have actual flame? cause like i said before i literally only get a flame for 2-3 seconds maybe

 

You want to see approximately 2.5 microamps of current flow. The microamp meter leads go in series with the flame rod.

Here's a video with a little more detail. Flame rod current measurement

 

I did that same test earlier yesterday on both the old flame sensor and the new one and both gave me similar reads....it would peak at about 1.9 but then drop out to almost 0 while the flame was still on. so could both flame sensors be bad or do you think i have a bigger issue?

 

replaced the whole board with a honeywell universal board and everything works fine now. the control module pretty impressive, fits over 140 different furnaces and comes with wire harnesses to match each brand so you cant mess up

 

Flame sensor has been replaced with no change, burner drop out after about 5 second of ignition, then restarts.
Any thoughts?

 

Welcome to the forums.

If you don't have a Nordyne furnace then you should start a brand new thread with your make of furnace. Mixing two problems in one thread is confusing.