Furnace trouble-shooting

[Perd Hapley]

My furnace has automatic ignition, or electrical ignition, or whatever they call it. I just turned it on last night, for the first time this season. The inducer motor comes on. Something (I think it's the ignitor) is clicking over and over again. After it fails to ignite, the clicking stops. I've checked that the gas valves are in the on position, all the way back to the meter. I'm also trying to get the ignitor and flame sensor out where I can work on them, but haven't succeeded yet.

Is it more likely the sensor is dirty, or that the ignitor is just broken, or...?

[Ron]

Make and model?

Is there a circuit board with an indicator light that will give you failure codes?

[never_retreat]

Was the gas ever turned off at any point?
I had the same problem with the water heater a few years ago. Just a bunch of air that had to work its way out.

[Perd Hapley]

They changed the gas meter some time back. May, I think. It's possible I haven't run the heater since then.

[never_retreat]

You could crack a pipe open and see if you can force the air out. Easiest thing to do might be to loosen the drip leg cap.

[K Frame]

You can tell when you've vented the air by using a match to check for gas.

[RocketMan]

You can tell when you've vented the air by using a match to check for gas.

Yep, when your eyebrows are gone, you've got gas.

[K Frame]

Yep, when your eyebrows are gone, you've got gas.

 

 

[Perd Hapley]

Make and model?

Is there a circuit board with an indicator light that will give you failure codes?

International Comfort Products

FBF075B12G1

[K Frame]

Name like that it sounds like a sex toy...

[Triphammer]

On your furnac, the ignition electrode is the flame sensor . It needs to establish flame at the pilot before it allows the main gas valve to open. You gas meter was replaced last spring so there is an air pocket in there somewhere. If you have a gas stove you've been using that should have removed most of it. You can try cycling the furnace a few times but with only the pilot orifice as an outlet it could take quite a few cycles. Opening a fitting or cap may be your best option, just wait 10 minutes between any venting & trying to start your furnace.

To back up just slightly, you mentioned checking valves back to the meter but did you check the one on the automatic gas valve in the furnace. I've missed or misread that one once or twice.

You are hearing the click so you most likely have spark so I'm looking downstream from there.

[Perd Hapley]

On your furnac, the ignition electrode is the flame sensor . It needs to establish flame at the pilot before it allows the main gas valve to open. You gas meter was replaced last spring so there is an air pocket in there somewhere. If you have a gas stove you've been using that should have removed most of it. You can try cycling the furnace a few times but with only the pilot orifice as an outlet it could take quite a few cycles. Opening a fitting or cap may be your best option, just wait 10 minutes between any venting & trying to start your furnace.

To back up just slightly, you mentioned checking valves back to the meter but did you check the one on the automatic gas valve in the furnace. I've missed or misread that one once or twice.

You are hearing the click so you most likely have spark so I'm looking downstream from there.

The valve inside the furnace was in the on position, along with the valve right outside the furnace, on the line itself.

I'm not sure about opening up a gas line and venting gas out into the basement. What is the correct, safe way to do this?

[K Frame]

Literally to NOT do it...

[K Frame]

Google it. There are a variety of instructions on line.

Check your furnace, some have a purge valve built into the gas valve that will bleed through the burner.

[Triphammer]

"What is the correct, safe way to do this?"

Yeah, what Mike said.

You're not really venting gas as, as soon as you smell gas or see a density change in the vapor, you're done. You don't let a bunch of gas come out. Not on purpose anyway. Nat gas is lighter than air and with a couple of cross windows open it'll dissipate pretty quickly but there is still a possibility for an accident. Sounds like this is your first time ( insert virginity joke) so you may just want to cycle the furnace.

If you do decide to try venting, make double sure the water heater is turned off & the pilot is out.

ETA: the pressure on the line is about 4inches of water column or adout 1/4 PSI so it's not like anything is "shooting out" anyway. And make sure you've tested anything you've loosened & re-tightened with soapy water to avoid
 
https://www.youtube.com/watch?v=mDAyu_sR3W0

this

[K Frame]

I think fisty got his furnace working...

I'm pretty sure I just saw someone flying overhead, and he appeared to be on fire.

[RocketMan]

I think fisty got his furnace working...

I'm pretty sure I just saw someone flying overhead, and he appeared to be on fire.

You saw a flying, flaming sock monkey?  Did it leave a cool looking smoke trail?

[Perd Hapley]

...a flying, flaming sock monkey...

This thought makes me sad. 

[Perd Hapley]

On your furnac, the ignition electrode is the flame sensor . It needs to establish flame at the pilot before it allows the main gas valve to open. You gas meter was replaced last spring so there is an air pocket in there somewhere. If you have a gas stove you've been using that should have removed most of it. You can try cycling the furnace a few times but with only the pilot orifice as an outlet it could take quite a few cycles.

Does this mean I just turn up the thermostat and wait, or will I need to turn the thermostat to off, and then call for heat again?

[Firethorn]

Does this mean I just turn up the thermostat and wait, or will I need to turn the thermostat to off, and then call for heat again?

I think you have to cycle the thermostat - otherwise after a while it just stops trying if it can't get ignition.  Don't want to fill your house with gas, after all.

[Ron]

Did you bleed the air from the gas line?

[Perd Hapley]

I think you have to cycle the thermostat - otherwise after a while it just stops trying if it can't get ignition.  Don't want to fill your house with gas, after all.

No filling the house with gas, got it!

[Triphammer]

You need to cycle the start sequence. You can use the t-stat dial, the system switch from heat to off if it has one or the power switch that should be mounted on the side of your furnace. The T-stat dial is obvious. If you use either of the other switches, turn the T-stat up above room temp and with the other switches on, let the start cycle go till it times out. Turn whichever switch off & wait 2 or 3 minutes. Turn it back on & let it cycle through again. Like I said, it may take quite a few if you haven't bled the line.

[Ron]

Is the pilot lighting but it isn't being sensed? If so then no gas is not the problem and you need to clean or replace the pilot sensor/assembly.

If you have a switch on the furnace you can just turn it off and back on to cycle the unit after it locks out on flame failure. Popping the filter panel on and off often works as there is frequently a door switch on it that kills power to the furnace.

You never mentioned whether there are indicator lights on the furnace/circuit board.



 

[Ron]

http://www.columbiapipe.com/PIN_ASSETS/PIN_Data/parsed/ICP_Commercial/Owner's_Manual/44103260900.pdf

It looks like you have an ignition module separate from the circuit board.

Please confirm that there is no flame at the pilot assembly.