Hello,

I have a furnace (York 36G24 natural gas) that is blowing cold air. The furnace was blowing hot air all this week up until last night.

When I turn power on to the furnace I get the following:
1. Green light for a few seconds while fan comes on. Fan stays on throughout entire process.
2. Amber light flashes slowly as igniter turns on, glows bright orange, and turns off.
3. When igniter get its brightest, I hear a "click," but there is no flame.
4. Igniter cools back down.
5. Same cycle 3 times with igniter glowing, click, cool down.
6. The blower comes on and the code I am getting is 7 red flashes: "Ignition lockout due to retries."

It is in a back closet that wasn't opened until the cold air started blowing. Also, there is another furnace (different natural gas model) in the upper part of the house that continues to work fine, so gas is coming into the house.

Things I've done so far, with testing before and after each "fix":

1. Removed each of the three nuts, one at a time, with the orifice for gas to pass through on its way to the burners. The purpose was to try and clean them out. I could see through all three of them fine initially, and blew them out with air just to be sure.

2. Removed the flame sensor and cleaned it with steel wool. It had a little corrosion on it and, although I didn't scrub too hard, it looks pretty shiny now.

3. I see condensation inside a couple of clear tubes in the area, but nothing appears to be clogged or frozen. I haven't touched these.

4. The handle for the gas line (just outside the furnace) is parallel to the pipe carrying the gas. I assume this means the gas line is open. I haven't touched the gas line (again, the furnace went from working to not working without anyone going in the furnace closet).

Thanks in advance for any help anyone might have to offer.

 

Check to be sure that the control valve on the electric gas valve is turned to the "on" position.


Use a multimeter to measure the voltage across the electric gas valve. You should have 24 VAC appear after the ignitor heats up, probably when you hear the click.

If you have 24 VAC and no gas, use the multimeter to measure the ohms (resistance) across the electric gas valve terminals. If the resistance is infinite you have a burned out gas valve.

 

Hello, I have a similar issue which happened during maintenance:

I have a York furnace - GY9S080BI2UP11A (8 years) which has a 36g24y gas valve. I shut the furnace to vacuum the blower. I turned the switch on the valve to off. When I turned the furnace on it did not come on (gave a 7 flash on the led), I looked saw the switch and turned it on. The furnace still did not light up even though this was now on. I turned the furnace off and after some time turned the furnace back on. This time it did fire. Is this normal that if you switch off the valve it does not come on in the same cycle and you have to wait sometime after the turning the furnace off. Or do I have a gas valve which is flaky because I repeated the sequence and it would not turn on had to switch off the furnace wait and then turn it on. Just concerned because it is getting cold to single temperatures at night and do not want an emergency.

Thank you!

 

Please don't piggyback on another thread. It rapidly becomes confusing.


Start a new thread and describe the make and model of your furnace and the sequence of events you observe when you turn up the thermostat.