19buick61

I have a Nordyne furnace 904639k kg7sc 038d-23a. The furnace was installed about a month ago in the horizontal position. When the furnace starts, it will run for usually 5-10 mins then the flame goes out. When the flame goes out the inducer runs for another 2? minutes then the blower motor runs for another 2 minutes. As soon as the blower turns off, the inducer turns right back on and the cycle starts all over. Sometimes after the first cycle the flame goes out as soon as the blower comes out and sometimes it runs up to about 10 minutes. Their are no codes flashing on the LED lights. Any help will be greatly appreciated.

Rick

paul52446m

Are you saying that the furnace burner comes on for 5 to 10 mi. and the blower does not come on all that time. If the blower is run by the electronic board, then that board is bad. paul

19buick61

The blower does come on a minute or two after the burner ignites.

paul52446m

It sounds like every thing on the furnace is working right. You are saying that when the burner turns off, the stat is still calling for heat, so its not coming up to the set point? You need to check the W post to C post on the board when the unit stops and see if you still have 24 volts there. Another check is try turning the stat all the way up and see if it keeps going.
A lot of things can cause this problem your have.
Thermostat setting not set right.
Limit switch opening,
Problem with drain
Being that there are no codes i am wounding if the problem is in the stat.
What kind of stat do you have? ways it replaced with the furnace? does it have a heat amp. setting in the stat? Paul

19buick61

Correct, it shuts down before coming up to temp. I jumpered the stat and it was still shutting down. I think its a honewell, I'll have to double check. It was new with the furnace I'm not sure what a heat amp is. I'll check the W and C post on the board after work.

paul52446m

What i am trying to do is eliminate the stat as being the problem. Some stat's have Heat anticipator in them that have to be adjusted to the amps going through them. This can make the cycle of the furnace longer or shorter
Other stats have small dip switches in them or on the base that have to be set of a 90+ furnace. Paul

19buick61

I read in another forum on here to take the wire for the w terminal and put it on the r terminal to eliminate the stat as a potential problem. is this correct?

paul52446m

That is right. If it still trips off then it is in the furnace. Paul

kok328

Paul, since the furnace was installed horizontally, could it be that the flame is not hitting the flame sensor enough to keep the system running?

19buick61

So I put my meter on that circuit and i was at about 24.5 v the furnace cycled 3 times in the course of raising the temp about 10 degrees.