Burner won't ignite, but all else seems well
#1
03-02-13, 09:22 PM
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Burner won't ignite, but all else seems well
I just finished replacing my inducer fan on a Heil furnace. The furnace came with the home, so I don't know how old it is. The stamp on the inside says it is Model No. FBF125J20A5, MFG. NO. NTG3125KJA5. I used the MFG NO. to determine the replacement part for the inducer fan and it seems a good match. I got it installed and everything seemed to work. The inducer fan started after flipping the switch with the thermostat appropriately calling for heat. The ingnitor clicked normally and the burner ignited. I then waited for the house to warm up and after an hour of the air being blown out of the vents, the temperature had old risen about 1 degree. I rechecked the furnace and the burner had gone out and would not reignite when I would turn the furnace off and on again. I then left it for several hours and it still would not reignite. The furnace had been working well for all of this season until the inducer fan seized up. If anyone can link me to a service manual or walk me through checking to find what is really wrong, I would appreciate it.
#2
03-02-13, 10:11 PM
Group Moderator
Welcome to the forums.
I believe this is the manual for your unit.
http://icpindexing.toddsit.com/docum...4001110401.pdf
You'll need to tell us exactly what your unit is doing......in order after turning on power and thermostat is calling for heat.
I believe this is the manual for your unit.
http://icpindexing.toddsit.com/docum...4001110401.pdf
You'll need to tell us exactly what your unit is doing......in order after turning on power and thermostat is calling for heat.
#3
03-30-13, 11:13 AM
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With the thermostat turned off (no call for heat). I turn on the power switch at the furnace unit and the inducer fan comes on. Nothing else happens. The exact same thing happens when I turn on the thermostat and there is a call for heat. I haven't gone through the manual yet. I will post more once I've done further testing.
#4
03-30-13, 11:34 AM
The inducer fan should not startup unless the thermostat is calling for heat.
You say that it starts up when you apply power to the furnace, even when the termostat is shut off. This would lead me to first double check all wiring in the furnace (something could have been bumped) and secondly I would suspect the circuit board.
You say that it starts up when you apply power to the furnace, even when the termostat is shut off. This would lead me to first double check all wiring in the furnace (something could have been bumped) and secondly I would suspect the circuit board.
#5
03-30-13, 12:03 PM
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I don't know if the instruction manual above is the correct one. It reports a pilot light, but the unit that I have has an electronic ignitor. I have 2 of the same units and the working one clicks repeatedl about 3 seconds after the inducer fan starts and then the burners ignite. The malfunctioning unit never clicks.
#6
03-30-13, 12:17 PM
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The inducer comes on no matter what. I checked and there are not any loose wires. The only wiring that I touched in replacing the inducer fan was the wire that go directly to it. I wired it the same way as the old one was removed. When I noticed that it was coming on all of the time, I swapped the 2 wires (1 white and 1 black) and there seemed to be no change it how it functioned, so I swapped them back.
#7
03-30-13, 05:03 PM
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So, a bit more information. I got the suggestion that perhaps the exhaust is not allowing enough air to pass. I tried the system with both a call for heat and no call for heat and get the same action. Both the inducer fan and the blower fan come on all of the time with no apparent action to ignite. Is there anyway to test to see what the problem is from here. I have a good multi-meter, but don't no where to look for the correct signals.
#8
03-30-13, 05:48 PM
Group Moderator
heil FBF series
The above should be the link to your manual. Check the fuse first on the main control board. It'll be a 4 or 5 amp plastic plug in fuse.
If that's good.....with the thermostat calling for heat.....see if you get 24 vac on ignition module/
The above should be the link to your manual. Check the fuse first on the main control board. It'll be a 4 or 5 amp plastic plug in fuse.
If that's good.....with the thermostat calling for heat.....see if you get 24 vac on ignition module/
#9
03-30-13, 06:12 PM
If your thermostat has a manual/auto switch for the blower, it should be in the auto position.
You say that both the blower and inducer are coming on as long as there is power to the furnace - even when the thermostat is not calling for heat.
That sounds like a circuit board problem.
Normally the inducer would come on as the first step on a call for heat, but the blower should not come on until you have a proven flame and the heat exchanger reaches a certain temperature.
You say that both the blower and inducer are coming on as long as there is power to the furnace - even when the thermostat is not calling for heat.
That sounds like a circuit board problem.
Normally the inducer would come on as the first step on a call for heat, but the blower should not come on until you have a proven flame and the heat exchanger reaches a certain temperature.
#10
03-31-13, 05:49 PM
Member
IF both the blower and inducer come on and you get no flame then that is typical of a high temp limit being open.
