My 16 yo Miller G6RA 096C-16 Gas Furnace went out last Thursday.
The DIM would come on
something would click
Igniter would turn red
Igniter would slowly fade out
Burners never come on, no flames
then continuous flashing red light on board

I installed a new HSI since the old one had never been replaced. I also cleaned
the flame sensor. Same results as above.

Furnace guy came out last night and tested the DIM and the gas valve. He said gas valve did open but furnace burners never came on and got the lockout. He said he did not think it was the gas valve and suggested I buy a new furnace. When he left, I turned power switch on, burners lit and furnace worked several hours. There were steady yellow light and steady red light on board. Furnace went out in middle of night and when I turned it off then back on, the flames came on for a few seconds and then went out. Now it does the same initial sequence of steps which is no flames in burners.

Is it the gas valve or another problem?

I'd appreciate any advice.

 

Welcome to the forums.

Strange..... it still sounds like a flame sensor issue. You need to read the trouble code before you reset the furnace next time. You should be able to see it without causing the furnace to lose power. Sometimes there is a sight glass in the blower door. In the link below is the diagnostics for your unit. Page 33 discusses failure and flash trouble codes.

Nordyne Literature/Manual.PDF

 

Sp,
Your flame sensor only comes into play if you have fire and it's not recognized. Your HSI is coming on, after a few seconds the gas valve is suppose to open and fire the furnace. When that happens the flame sensor will tell the control all is well and it will stay running. For some reason although your igniter is working your gas valve isn't getting the signal or is getting it but not opening up.
Either way I think I would get another tech if need be because I don't think that's any reason to replace the furnace.
If you have a meter and know how to use it see if you ave 24v at the gas valve. After the igniter lights see what the voltage is then to see if it's getting the signal.

Good Luck,

 

Hi PJmax,
I turned furnace on again. The burners actually ignited for 2-4 seconds then wenteverything shut off; igniter, flames and DIM. I have turned furnace on several times today but burners have not ignited again. After each time, the red light flashes constantly on the board; there are no pauses between the flashes.

HI Sportt,
Burners actually came on once today. I have a meter but is this a test that I can perform myself? No experience with furnaces other than what I've read online the last few days. Furnace guy said he tested the valve and it was open and he smelled gas when valve open. I wasn't with him when he did it. I saw a YouTube video where a guy said his valve was stuck and he would hit it with a wrench and the burners would light until the thermostat was satisfied. Could this be a possibility?
I have a new wall furnace in my family run that warms my house if I set it @ 85degrees so I hAve time to try to figure out the problem. Don't want to buy a new furnace just yet
Thanks to both of you for helping me
Sandra

 

What the heck is a DIM? l[-ksfokldf,gjaoA0IDFKS

 

Furd,
DIM IS the Draft Induced Motor.

 

Sp,
You're saying the igniter comes on, the next step is for the gas valve to open by itself.
I'm guessing that when the tech said he tested it, and smelled gas he probably jumped it out to make it open, which means he bypassed the circuit. If he has to jump it out to get it to open there's a problem somewhere.

With your meter set to read AC voltage put it on the terminals of the gas valve and see if you get a reading. You should see 24v with your meter. If you do start the furnace and when the igniter comes on check the gas valve and see what you get.
Do you have the book for the furnace.

 

I posted a link to the manual in post 2.

 

P,
I did see that and if that's exactly what he has once the igniter comes on the gas valve should open about 3 second later. It would seem to me that there should be something to prove the ignitor is on but it doesn't show anything there. You have to remember this is 16 yrs. old. They didn't require all the safety's back then.

 

Sport,
I checked gas valve with 2 different meters but did not get any voltage at all. Stayed at 0 other than something like a hyphen Mark (-) flashed.I tried to contact the furnace man who came initially to ask him exactly what the meter showed when he performed the test but couldn't reach him. I will have my brother-in-law do the test tomorrow.

PJmax,
I did download the manual. Thank you again. I also read the troubleshooting section & followed the instructions about resetting but it didn't help.

As I previously mentioned, the furnace came on 2 days in a row (once each day),
but burners went out in 2-4 seconds. Does that help eliminate any choices?

 

If the burners actually came on then went off you may be looking at the flame sensor.
Check voltage at gas valve without a call for heat. See if you have 24v. With call for heat 0v.
That means valve is working. That's how the low voltage works on these controls. It's called floating voltage.it's still there but it doesn't show on the meter. T-stat act the same way. 24v when off, 0v when calling.

 

The burners coming on for a few seconds tells me the flame sensor is the issue. If it was the valve it normally wouldn't come on for just a few seconds.

Doesn't that board have a diagnostic light that blinks trouble codes ?