When it starts up everything appears normal, the induced draft fan starts for about 30 seconds, the glow plug gets red hot, the gas ignites, about 30 seconds later the main blower wheel spins. The hot air comes out of the registers and everything works great but only for about 5 minutes, then for some reason the flame stops and about 2 minutes later the main blower wheel stops? The only thing running is the small draft for about 5 minutes or so then it finally kicks off. All is now quite for about 15-20 minutes and the whole cycle starts up again. I cleaned the flame sensor and it did no good. Now this portion is very difficult to explain, but when everything stops there is a very slight "hint" of odor coming from the registers (almost unnoticeable unless you put your nose right next to it)... smell like maybe something electrical burning out or failing? My guess is maybe the main blower wheel giving out? IF that is it then why would the flame stop THEN the main blower stops, I would think it would be the opposite if it is the blower?

This all started a few days ago but it has gotten much worse (now I can not warm the house up at all).

I would greatly appreciate some good advice here, I'm unemployed.

Thank You Everyone

I forgot to mention that this is a natural gas furnace and that the red light on the circuit board remains solid red (no blinking)

Is the filter clean?

Are all the registers open?

NO, We have a 5 bedroom/3 full bath home and a few bedrooms and a bathroom we leave the reg. closed because they are never used (we have done this for years now)?

And the filters is clean

The reason for the registers being closed is the fact that closing them can trip the high limit control which might give the same symptoms you are having now. Something in the control system is cutting the furnace off before the thermostat is satisfied. You need to check the circuits(usually with a meter) to tell which one is causing the problem.

I was wrong earlier, about HALF the reg. were closed (idea was to save on heating bill, not a good idea I now realize). Will opening the reg. fix the problem... I just opened them all

Also would you mind telling me eactly how to check the circuit board (circuits)

Well checking the circuit board is always left for last. I will provide you with a DL for your manual and you can take it from there. This is a Goodman factory manual and the best source for info around BUT pay attention since this manual covers many different models so make sure the instructions etc pertain to your exact unit model number.

http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf

I can see opening all the vents is a bit too late now, same symptoms occurred (regardless I will leave them all open)

hvac1000 thank you for your assistance.

May I ask are the circuits you are referring to on the circuit board?

No they are limits/other control safetys like rollout switches/fan controls etc. That book I sent you has all the info but you have to be able to read it and understand what it says. To do heating repair you need experience working with electric and electric devices and for most home owners it is over there head. Sorry not being a smart a$$ but I think you know what I mean. You have the skill or not? Only you know your level of talent I just provide the book to make it easy..

I agree, and I will give it a whirl. Thank you again & I will keep you posted, you do not by chance live in the Cincy area in case I could use some hired help down the road do you?

Sorry but I am not for hire. Any extra time I have is donated to one of the local universitys to help further the education of both young and older men and women interested in advanced discussions/education of the HVAC trade plus I also learn something new almost every day since NO ONE I ever met can no it all about HVAC. The trade is probably the most complex issue going and has been that way for many years.

OK I now think it is the blower motor, Iexamined the cycle again and the blower motor stops spinning THEN about 1 minute afterwards the flame discontinues and I get 4 red blinks off the circuit board. I just took the motor off, it says GE V064AS as a part number. Any ideas where I could purchase one?

Also there is another number on the blower motor 5KCP39FG

I have a blower motor failure on my natural gas furnace Janitrol GMP 075-3. On the motor it says a GE 5KCP39FG then in very bold there is V064AS? Where can I get a replacement, I am having a terrible time finding one.

Thanks!

It could be the motor run capacitor causing the problem. Did you test for voltage at the motor wires after the motor stopped? Just because the motor stopped does not mean it is defective unless tested first.

Look in your yellow pages under electric motors. Usually there is a local company that sells and also rebuilds old ones. You can usually take the capacitor ALONG with the motor to them and they will test it for you. Call them and find out before you drive there.

Thank you hvac1000, i will keep you posted on the progress!!

OK do that.