Gas and Oil Home Heating Furnaces - Gas Furnace Burners Flutter And Shutoff (intermittent problem)

I have an intermittent problem with my gas furnace which I have been struggling with for the last 10 days. Now I know a little bit about these than before by going through the messages and responses in this wonderful forum. Following is the information about my furnace:

I think it is about 12 years old. The name plate tells me that it is made by HQCO Manufacturing company, Nashville, TN. There 2 model numbers NUGI175DK03 and 867.767062. In browsing parts at sears.com I am given to think that this is actually a KENMORE furnace.

The pilot is lighted by spark on demand. There are 6 burners altogether. Following is what I observed in the normal working condition:

1. Demand for heat comes from the thermostat
2. Ignition module (Honeywell S8600M) activates spark and also opens pilot valve
3. Pilot flame shows up and then the gas to the burners are sent by opening the main valve.
4. burners light up and are on for 90 seconds (NO BLOWER DURING THIS TIME)
5. Blower comes on after 90 seconds
6. Burners are off in another 90 seconds but blower continues to be on
7. After another 2 and half minutes the cycle repeats from step 2 above

The problem I currently have is the furnace dies suddenly. At times I have noticed that the burners flutter and stop. At other times when the demand for heat arrives, I hear one tick in the control module but nothing happens after that. In each case when the furnace gets into trouble, the unit will not come back on until I 1) recycle power 2) wiggle horse shoe connectors in the ignition module. Later I noticed that the “wiggle” fix is just coincidental because repeatedly recycling power several times also brought life back to the furnace.

The other thing I noticed is there is always some humming noise (from transformer?). This noise remains even after the furnace starts experiencing the problem. And it is there even in normal working condition. Is this a problem?

I appreciate if you could share your experience in troubleshooting my problem. The next thing I am thinking of is to buy a multimeter and check voltages in the gas valve and control module. Do you think this will help to diagnose the problem?

I have a sneaky suspicion that this is related to some “solenoid” that is acting up. But I don’t know where to look though….

The furnace was made by Heil-Quaker or Inter-City Products (same company just different name) depending on when the furnace was made. Sears doesn't make anything except money. ;) Enough history. The fluttering makes me think gas pressure is going away for some reason. Is the furnace being fired on LP or natural gas? I'm not sure if this furnace has a board which blinks a code or not. Some ICP furnaces had a board in the fan compartment but no little window thru which you could see the blinks, duh. The next time it acts up, try to find the little window & count the blinks. If there is a blink code, the key should be on the inside of the blower door.

The Honeywell 8600 control is sensitive to grounding first make sure that there is a good ground in the 4s box and at main panel.
Then if that is grounded then you can read the rectified voltage coming back from the flame sensor at the 8600 control this will tell you wether there is a problem with the flame sensor or the control. I would be checking this first if I was there.

Try cleaning the flame rod

Thank you for your replies.

Grady, The furnace is run by natural gas. There are no LEDs that I can see. There is no mention of any codes on the reverse side of the top and bottom panel. I just see a wiring diagram.

Scottg, What is 4s? Is it my Honeywell S8600 (located in the burner compartment)? Or is it the one where there is a transformer (located in the blower compartment)? What is main panel? Is it where the external power switch is located (240V supply) in a switch box? And also, how do I check if I have good grounding or not?

mbk3, Can you please tell me how to access the flame rod? If there is a picture in the website that would really help. Is it something that I can clean with a sand paper? Thanks.

The 4s box is the box that power comes into.
Your main panel is your main circuit breaker box.
You check your ground by making sure they are tight.
Be carful possibility of electricution.
The flame rod is one of the two rods that produce a spark near the burner.
And you can clean it with sandpaper.

When is the last time you had this thing cleaned and safety inspected by a pro? You very well could be going out on a high limit safety due to a dirty heat exchanger.

Do you have a clean filter and are all the return and supply ducts open?

Thanks for your response... The furnace was inspected by a pro two months back. He did not find any thing wrong with the appliance at that time.

I do have a clean filter. All the return ducts are open. I have always closed a few floor vents. Nerver had a problem.

Called a furnace pro. He replaced Ignition Module for $220US (part)+ $86US (labor). The furnace seems to work fine now. The old module was a Honeywell S8600M. The guy replaced it with Honeywell S8610U 1003. Can somebody tell me if the new one is a good replacement for the old one? Thanks.

ISE-DISP

That is the direct replacement for that control. I have one of those on my truck also.

Nice to have heat again huh.

That is the problem with controls they can work fine today and tomorrow go out.

I only have a few customers that really do any type of preventitive maintenance as in changing out controls before they go out.

Scottg,

Thank you!!!

ISE_DISP