# My new Nordyne furnace doesnt want to stay running



## 19buick61 (Dec 14, 2011)

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


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## paul52446m (Dec 14, 2011)

19buick61 said:


> 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


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


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## 19buick61 (Dec 14, 2011)

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


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## paul52446m (Dec 14, 2011)

19buick61 said:


> 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


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


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## 19buick61 (Dec 14, 2011)

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.


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## paul52446m (Dec 14, 2011)

19buick61 said:


> 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.



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


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## 19buick61 (Dec 14, 2011)

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?


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## paul52446m (Dec 14, 2011)

19buick61 said:


> 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?



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


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## kok328 (Dec 14, 2011)

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?


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## 19buick61 (Dec 14, 2011)

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.


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## 19buick61 (Dec 14, 2011)

ok so I have been sitting here staring at my furnace for an hour or so.  just before the furnace shut off I heard some noise coming from the inducer motor and I the green LED flashed half a dozen times while the red stayed solid.  According to my book that means pressure switch open fault.


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## 19buick61 (Dec 14, 2011)

So I have been staring at my furnace for an hour now.  I heard some noise come from the inducer motor, maybe some water on the fan blades? then as the furnace shut down the green light flashed several times while the red stayed solid.  the burner went out the green light came back on solid and it cycles and started back up again brinign the room up to correct temp.


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## paul52446m (Dec 14, 2011)

kok328 said:


> 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?



In most of these furnaces today, they have what i call small jet burners.
 If they have the right gas pressure, they will work fine in different positions.
Running 8 to 10 min. and then cutting out, sound more like water build up and when the inducer turns off it drains so it can come back on. Another thing is, if he is not moving enough air through the furnace, it could be stopping on limit
 switch. The next things i want him to do is check the air temp. on the return side and on out going side to see if it is over heating. 
 Another thing is to watch the burner and when it turn off turn the stat down and see if you get a code.  Paul


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## paul52446m (Dec 14, 2011)

19buick61 said:


> ok so I have been sitting here staring at my furnace for an hour or so.  just before the furnace shut off I heard some noise coming from the inducer motor and I the green LED flashed half a dozen times while the red stayed solid.  According to my book that means pressure switch open fault.



If you get too much water in the inducer then the pressure switch will open. 
 You need to get you booklet out that came with the furnace. When you lay a furnace down, changes need to be made, you need to make sure they did this  right. Some times the inducer has to be moved and the drain hoses and pressure switch hose have to to be moved. 
 Your stack has to maintain a up hill pitch from the furnace to the outside, and supported so they don't sag. There is a special fitting when your stack leaves the inducer. The inducer should kick the water out as soon as it fires up and when every thing are installed right you should not get that much water.
  If you wan't to take some pic. of the inducer and stacking, and hoses and drain , i will be glad to look at them.   Paul


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