Inter-City propane furnace?

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stmar

Burning Hunk
Sep 12, 2014
225
Wyo
My furnace is calling for heat but is not igniting. In the past it has taken a while to fire, sometimes it fires quickly. I have not torn into it yet, it is in the cold attic and we have the pellet stove running, but I am thinking it is the igniter. My manual is showing part #1009524 and doing a search I am finding this: Does that look like the correct part and how hard is it to replace? I just replaced my gas dryer igniter and pellet stove igniter so I guess it is the season for igniter replacements. Forgot to ask: Do you test the same way as the dryer igniter, with an ohm meter?

[Hearth.com] Inter-City propane furnace?
 
Was able to observe a bit and there was a glow which I assume is the igniter. Is it like an oven where you cannot judge that it is working just because it glows? I don't hear any clicks like it is trying to light. Did not have enough time to tear into it tonight but will start testing components in the next few days. Any ideas of what to test and how would be appreciated.
 
Does it have a thermocouple? It may be defective and not allow gas to feed.
 
The manual does not show a thermocouple but I will double check when I start looking.
It looks like it is the flame senser type.
 
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Perhaps the flame sensor is bad...? Check any wiring connections, and for broken wires.
 
After I got into it there was nothing familiar, nothing like what I had been viewing online or in the manual. It has a Honeywell gas valve and the igniter is mounted in/on the valve and I can't get it out, there is a plastic shroud/cover that I don't want to break. There is a "striker" in the gas tubes. Cold snap coming and the pellet stove does great but want the added security of central heat so called service tech, hopefully he can get it going again.
 
Service tech got it fixed without any new parts, he disconnected what he could and cleaned it thoroughly. Reworked the flame sensor and it worked. Hopefully that will do it, although he said the gas valve may be the culprit and be intermittently causing the problem. It is a Honeywell Smart Valve and he said that there was no way to diagnose one of those, they don't throw codes, and I imagine they are expensive.
 
Glad you got it fixed. Enjoy the heat!
 
When the tech turned on the furnace after he cleaned and adjusted the igniter/flame sensor, it fired up quickly, several times. This morning it took some time, a few minutes, maybe longer, to fire. What determines the length of time from when the stat calls for heat to when the furnace fires? Yesterday it was about 40 degrees warmer and the wind was not blowing, this morning it is cold and windy, would that make a difference?
 
Back to square one. Why is it that when the tech is here everything works but when he leaves it acts up again?? From what I can gather it seems like an intermittent gas valve issue. This weekend when I have some help I will take a look at it and see if I am getting a pilot to activate the flame sensor. It is in the attic and a bear to get to. It also looks like a replacement if it is the valve, Honeywell Smart valve.
One thing the tech told me was to "not" get a new furnace since mine is in the cold attic and the newer units are environmentally sensitive and I would have problems. I guess putting hundreds of $$$ into this one is the best/only choice. Anybody have any experiences with the Honeywell Smart valves?
 
Observing the igniter/flame sensor everything looks normal but no pilot lit. So I blow on it and it fires up. For some reason the gas from the pilot tube is not getting close enough to the igniter to light. I ran through several scenarios and it would not light until I blew on it. The igniter is stiff and I don't want to break it. Can you adjust the pilot tube to be close to the igniter or do you have to bend the igniter? At least it is not the $$$ valve.
 
don't try bending the igniter itself you break it. you should here snapping like a cook stove but faster. if not and you hear a slow snap you might have a bad spark plug wire and it's jumping out the wire to ground. be careful when it is trying to light. 10 to 15 thousand volts on that wire. there should be a ground wire going to the assembly if it not a good connection spark can't jump. sometimes you can bend the bracket so the igniter is closer to the pilot and that takes care of it.