Furnace goes out

glb · 01-03-2008, 08:38 AM

My Lennox furnace will run for a few days and then got out. I have sat in front of it and witnessed the process of when this occures.

The pilot is burning and the flame is touching the coupler. The furnace ignites and the gas burners have a flame of about 1 to 1.5 " . After a few seconds the burner flame will drop down to about .75 of an inch and the pilot flame reduces also BUT only the tip of the pilot flame is on the coupler. I am assuming that the couple senses loss of the pilot and then turns the gas off.

Is the gas suppose to go down after a few seconds ? It seems the entire pressure is reduced as it affects the pilot also. I have just had both outside stage regulators on the LP tank and the one next to the house replaced with new ones. It is also a new coupler installed next to the pilot.

The problem has not changed. I go upstairs and my gas stove is working fine. I have contemplated adjusting the coupler ( bending the holder ) to move it a bit closer to the pilot. as of now it is at least 1" away.

Thanks for any help

mcvane · 01-03-2008, 12:03 PM

Our furnace tends to start sometimes and you see the gas flames for a few moments and then they die down...but the furnace is still pushing the air out for a few minutes more.

However, in my case, I think it's not an issue, it's a matter of the burners shutting off to match the thermostat's requirements - because if I happened to crank up the heat, the burners would stay lit until the temperature of the thermostat was reached.

That's my insight into this...but you may or may not have an issue there.

glb · 01-03-2008, 12:13 PM

nope, not my issue. I also had a new thermostat installed. Inside temp can be 58 and set thermostat to 65. Still goes out.

If the temp is reached the pilot should still stay lit anyway. My issue is the furnace is completey turned off gas wise. I have to relite the pilot to get it to go.. then it may run for a few days and they go out again.. usually at the most inoppourtune times.

glb

redline · 01-03-2008, 05:56 PM

How old is the furnace?

bigMikeB · 01-03-2008, 06:43 PM

You need to have the pressure tested at the gas valve with a manometer, it should have @11" of pressure suppling the valve. Who replaced the regulators for you? Did they set them up in warm weather? Low tank temps effect propane. I strongly reccomend a professional doing this work, many a homeowner has had bad results dealing with propane.

glb · 01-04-2008, 08:10 AM

My best guess it the furnace is 10 yrs old. The LP people came out and replaced the regulators, checked the lines etc. When they did all that it was about 25 degrees out.

bigMikeB · 01-04-2008, 06:02 PM

Then something else is wrong there. You need to have them come back out and check it. The last thing you want to happen with propane is a delayed ignition situation.