Furnace advice needed.

[ToadHill]

I just got a call from the neighbor that the Electric company replaced the transformer that services his place and mine.

I took a ride out this morning to check that all was "OK". I found out that the furnace was not working. I checked the breaker and it was not tripped. I turned off the furnace and then turned it back on.

The purge system operated, the igniter lit and the burner snapped on and lit. It ran for about 30 seconds and then the burner went out. The blower finished the cycle and then shut off.

Each time I repeated the process the same thing happened. Well the water in the commode is frozen and the pipes that go to the bathroom sink are frozed, (they are pex so I may be alright there) I'd really like to get the furnace working. Anyone have any ideas?

One other thing, my propane supplier just added a little over 100 gallons to the tank about a week ago, could I have been delivered a bad batch with water in it and perhaps the line or regulator is frozen up?

 

[Steve_Miller]

I just got a call from the neighbor that the Electric company replaced the transformer that services his place and mine.

I took a ride out this morning to check that all was "OK". I found out that the furnace was not working. I checked the breaker and it was not tripped. I turned off the furnace and then turned it back on.

The purge system operated, the igniter lit and the burner snapped on and lit. It ran for about 30 seconds and then the burner went out. The blower finished the cycle and then shut off.

Each time I repeated the process the same thing happened. Well the water in the commode is frozen and the pipes that go to the bathroom sink are frozed, (they are pex so I may be alright there) I'd really like to get the furnace working. Anyone have any ideas?

One other thing, my propane supplier just added a little over 100 gallons to the tank about a week ago, could I have been delivered a bad batch with water in it and perhaps the line or regulator is frozen up?

Flame failure, photo eye not detecting the flame? Try cleaning the eye if you can find it.

Steve

 

[Kays Supply]

Good advice on the water idea. My 1 year old York High tech gas furnace had a sensor on the flue go bad that told the brain the water level in the drain was high. Ice would trip the same response.

 

[dodge man]

Ditto on the flame sensor. There is a sensor that detects the flame, just to make sure the furnace is lit and doesn't keep pumping out fuel that isn't burned. Ours got dirty and did what yours is doing.

 

[milkman636]

Was your circulating fan coming on shortly after the main burners lit? or just your combustion blower? It sounds like the burner is lighting. If the circulating fan is not starting, your burner may shutting off on a high limit safety.

The sequence is: combustion blower starts purge, pilot flame lights, pilot flame prooves and the main burner ignites, circulating fan starts and blows warm air through the house. It sounds like you got all the way to the circulating fan part of the equation.

If there is a flame rod just above the burner, usually just giving it a quick polish with something abrasive will get it back in service. There should be a flashing trouble code after the burner shuts off either way. Usually there is a sticker in the furnace somewhere that will tells you what the flashes mean.

 

[milkman636]

In a cold furnace, would it overheat or turn on the circulating fan in 30 seconds?

About 30 seconds is a relative. The flame rod is a liklely possibility, but if flame is proving and fan is not starting, the fan may need to be checked.

There is more than one possible scenario, the flashing trouble code should solve the mystery of where it is falling down.

 

[KubotainNH]

These new furnaces can be a pain. Although mine is oil fired I need to adjust it for the season or I get flame outs. Mine pulls in outside air so it seems the change in air pressure, humidity etc...seems to affect it. Maybe it is now too cold where the furnace is for it to have bright enough flame for it to think it's running. Do you have an air adjustment on yours so you can try making a brighter flame until warmed up? Just a thought. 30 seconds doesn't seem long enough to warm up the furnace enough for a blower.

 

[ToadHill]

No code flash. My son suggested to check the roof and see if the chimney is covered with snow, it may not be getting the makeup air it requires, I'll look tomorrow.

 

[von-mil]

My furnace had similar symptoms about a month ago. In my case, the problem was a clogged condensate trap that was causing the condensation to back up to the point where it was inside the housing of the fan that sucks outside air into the furnace. As a result, the fan was unable to generate enough negative pressure thus causing the system to shut down. I removed the condensate trap along with all the backed up water, cleaned and replaced it, and all has been fine since.

Your unit may have a status indicator light (or lights) that can provide you with some diagnostic info to go off of.

 

[kenmac]

If his furnace vents into chimney . He doesn have a condensate trap. Those are only on high efficiency condensating furnaces.Don't use sand paper to clean the flame sensor rod. Use mild steel wool