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

 

[zzvyb6]

So did the transformer change affect the furnace (or not)? If there is a blower motor overheat would there be a code set?

On mine, the intake air got plugged with a cold animal's nest. That caused a computer check and a code was set. Without a code, its going to be guesswork. Can you start the blower manually for full time operation to see if its the problem?

 

[Sigarms]

Without a code, its going to be guesswork.

I've seen numerous occasions where without a dedicated ground circuit for the furnace, you can never rely on what a self diagnostic board is "telling you".

We call them idiot lights at times because if you follow them blindly, you end up replacing parts without figuring out what the actual problem is and may not solve the issue to boot (and some guys do that without the boards help as well). That's not taking into account that sometimes you're getting a "double negative" (think that's the term) that is giving you a misreading on the board to begin with.

1. Check ground to furnace (should be a dedicated ground)
2. Check gas pressure (inlet and outlet)
3. Check standby and running - line/low voltage / check ALL wiring
4. Check tubing and verify rated pressure for pressure switch/switches

Without a decent manometer and clamp meter ("rated" for HVAC use), yes, you're pretty much guessing.

Don't use sand paper to clean the flame sensor rod. Use mild steel wool

+1

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.

Unless the furnace is using a two pipe system or some sort of concentric vent kit which most likely isn't the case (because we're assuming you have a standard 80% non variable speed gas furnace being vented on through the chimney by your comment), the chimney would have nothing to do with make up air (air used for combustion), but something could be obstructed in the vent, which could be causing a pressure related issue.

 

[ToadHill]

I took the grandson out with me to the farm today and he got up on the roof with a shovel. He cleared out an area about 5 ft. on all sides of the chimney. It is a pipe within a pipe system. I went inside and started up the furnace and it ran just fine so lack of combustion air must have been the problem.

Thanks everyone for the ideas.

The chimney only is about 24" from the roof and when the snow drifts over the peak it must have covered it up. I guess I'll have to find a piece of pipe to add another 2 ft. on the top so it won't happen again.

 

[tommu56]

what control does it have on it my york and the honey well have an led that blinks a code for fault.
my original youk board died and I put a generic replacement in still blinks a code on board. but you have to take 3 covers off to get to it hold safety switches in and turn on power on then watch led and count the pulses.


That said does the air fan start?
if it doesn't start i would look at the rate of rise limit or high temp limit the a flame detector which is a stainless steel probe in some if its stainless steel some can be cleaned with a stainless steel pad or use a scotch bright pad.

tom

 

[Travelover]

Friend of mine has a high efficiency furnace with the two plastic pipes - inlet and exhaust. He called up the furnace repairman 'cause the furnace won't heat. Repair guy shows up, stomps on his hosta plants growing in front of the pipes, then charges him $100. :laughing:

 

[Steve_Miller]

I took the grandson out with me to the farm today and he got up on the roof with a shovel. He cleared out an area about 5 ft. on all sides of the chimney. It is a pipe within a pipe system. I went inside and started up the furnace and it ran just fine so lack of combustion air must have been the problem.

Thanks everyone for the ideas.

The chimney only is about 24" from the roof and when the snow drifts over the peak it must have covered it up. I guess I'll have to find a piece of pipe to add another 2 ft. on the top so it won't happen again.

If it did have a photoeye and a lack of air it may have been running to rich and smokey causing the eye not to pick up the flame. I remembered after the fact that a couple years back that my furnace (forced air) would run for several minutes and shut down, then restart over and over, after a couple of days I figured out that the air filter in the plenum was plugged to the point that there was not enough air flow causing the plenum temperature to rise to the point that it shut the burner down until it cooled then restart. Just another tidbit of info.

Steve