[marchvac]

before you condemn the board you should get a votmeter and check the pressure switch, gas valve and limits. It could also be the thermostat. You would have to disconect the wires from w and r and jump them out.

 

[yuri]

Why did you change the igniter? Where did you get it from? There are several versions of that igniter and they have to match the model AND series of that furnace and circuit board. Hope you got the right one. Universal igniters DO NOT work with Lennox units as Lennox uses a reduced voltage system for them. Marchvac is heading you in the right direction.

 

[marchvac]

Hey Yuri long time how is things. I had to do a job in regina last fall

 

[echo6romeo]

Hey Yuri long time how is things. I had to do a job in regina last fall

I purchased the igniter because I thought that may be the problem which wasn't. It's not the Lennox original part but looks pretty close. Either way, when I installed it, nothing changed and it still ignites the burners like the other one did. Now the flame sensor I purchased from Cozyparts and its the original part. I do have a volt meter (not digital) but not sure how to test the pressure switch, gas valve and limits...

 

[echo6romeo]

Here's my meter.

 

[marchvac]

After the furnace lights the pressure switch should stay closed which means you should have no voltage across the two terminals. If the gas valve has 24v and shuts off then the valve is bad. But it could also be the thermostat.

 

[echo6romeo]

Here's my meter.

I'm not even sure if this type of meter will work.

 

[echo6romeo]

After the furnace lights the pressure switch should stay closed which means you should have no voltage across the two terminals. If the gas valve has 24v and shuts off then the valve is bad. But it could also be the thermostat.

Can you please explain how to check the pressure switch with the volt meter (I'm new to the volt meter and the furnace).

Also, just an update, the unit has been running for several hours now since I reset it to clean the burners. The fan is always running, the LEDs are displaying normal operation, the igniter is igniting the burners which will burn for 3 seconds before turning off. This process of trying to keep the burners on for more then 3 seconds keeps repeating after about every 20 seconds of rest/ burners off. Still no lock out mode.

 

[echo6romeo]

Can you please explain how to check the pressure switch with the volt meter (I'm new to the volt meter and the furnace).

Also, just an update, the unit has been running for several hours now since I reset it to clean the burners. The fan is always running, the LEDs are displaying normal operation, the igniter is igniting the burners which will burn for 3 seconds before turning off. This process of trying to keep the burners on for more then 3 seconds keeps repeating after about every 20 seconds of rest/ burners off. Still no lock out mode.

This is a picture of my unit:
Lennox G43UF -36b-070-08

 

[echo6romeo]

This is a picture of my unit:
Lennox G43UF -36b-070-08

It's FIXED!! I just unplugged the red tube from the pressure switch and blew in it to clear it. That's it.

 

[college A/C]

message to echo

You still need help echo?
Have you tried to clean the draft blower tube yet? The rubber tube is connected to the induced draft blower housing where the flue pipe comes into the unit. remove that end of the rubber tube abd clean out the fitting with a small piece of thermostat wire or stick pin (what ever will fit through the hole aboutv 1-2 inches) if you meet resistance then scale has partialy plugged the hole and the wire should clear it. put the tube back on and try to relight the furnace. let me know if it works for you

 

[echo6romeo]

You still need help echo?
Have you tried to clean the draft blower tube yet? The rubber tube is connected to the induced draft blower housing where the flue pipe comes into the unit. remove that end of the rubber tube abd clean out the fitting with a small piece of thermostat wire or stick pin (what ever will fit through the hole aboutv 1-2 inches) if you meet resistance then scale has partialy plugged the hole and the wire should clear it. put the tube back on and try to relight the furnace. let me know if it works for you

No thank you. I fixed it by blowing into the red tube which is connected to the pressure switch. All fixed.

 

[pmorganii]

Fixed

Things are getting cooler in Texas and my downstairs furnace would not light...upstairs worked fine. After searching the internet, I found this forum. I removed the ignitor sensor and cleaned...no luck. Then I found this answer...removed red rubber tube, cleared it and cleared both ends out with a long paper clip...fired up after that. I could hear some tinking when the fan turned back on...assume that was the blockage.

Thanks!! Downstairs is warm again.

You still need help echo?
Have you tried to clean the draft blower tube yet? The rubber tube is connected to the induced draft blower housing where the flue pipe comes into the unit. remove that end of the rubber tube abd clean out the fitting with a small piece of thermostat wire or stick pin (what ever will fit through the hole aboutv 1-2 inches) if you meet resistance then scale has partialy plugged the hole and the wire should clear it. put the tube back on and try to relight the furnace. let me know if it works for you

 

[TwitterD]

Hi All,
I had the same issue happen to me last night and this thread helped me resolve it. I had a hard time figuring which red tube to clean out on my unit "Lennox G51MP", so I wanted to include a picture in case it helps someone else in the future.
Thanks.:thumbup:

 

[jayfern10]

Thanks for posting the Fix Yuri.

I had similar symptoms and cleaning the flame sensor worked. For a while I thought it might be the blower because it would come on at times, but only run for 3-5 minutes. I'm glad I found your post. Temperature in NY tonight about 29 degrees.

 

[JohnPlo]

Similarly connected?

Dear Santa :santa:,

I know you won't be back until next year but I am left out with a sick furnace. Please help me.

I have a Lennox Elite Series Furnace with pretty much connected problems with the ongoing thread.

This one, my furnace/burner kicks in but the blower would not come on. Actually, the blower clicks in, on and off several times and if I get lucky sometimes it picks up, otherwise, it just clicks and clicks. It's trying to turn on the blower but somehow it just can't.
Because of the many clicks, I have to manually turn off the Thermostat. At this point the burner's heat is wasted bcuz it was never circulated and picked up by the blower.

Any input would be greatly appreciated... grrrr (I'm cold).
Thank you

 

[carmon]

sounds like the board is having issues......:furious:

 

[JohnPlo]

Carmon, thanks for the input.
Any specific I need to do on the board? I don't feel like replacing the whole board. But if I do, what are the possibilities to check first before it goes into the dump? I am the type of guy that gives a little fight first before I fold.

Thanks.

 

[Dave Sal]

Does your furnace have a little window over the integrated control panel? If so, take a peek in there and see if there are trouble codes flashing on the LED's. I have a Lennox G60 which has this diagnostic feature.

 

[JohnPlo]

Blower not kicking in after burner stops

Hi Dave, unfortunately, I don't have the screen window. I have a Lennox Elite Series G24M4 model which is fairly not that old I think.
But I notice there are 2 blinking LED lights. I'm not really sure if that's normal (is it?) since I didn't pay attention to it the first time if they're supposed to be stationary in the normal state.

What I did though is cleaned up the thermocouple/flame sensor and it's still remained to be seen at this point. I did this bcuz the burner does not hold long enough - it turns on for about a minute then off in seconds and back again.
I thought this probably confuses the blower when to do her own time dance...

Thanks again