Home and Auto Furnace!

cosmo20002 · 10-29-2015, 10:56 PM

Furnace ain't working.
Pilot light is on, no problem. Bluish flames. But the burners won't ignite.
Fusebox is fine. Tried turning everything off and vacuuming out crud and debris.

So, when when I change the temp on the wall thermostat to make the heat kick on, nothing happens.
If I switch the thermostat setting to "ON" instead of "Auto," the blower kicks on, but since the burners don't ignite, there's no warm air.

Llast night I turned on the heat for the first time of the season. Worked fine, and I assume it turned off when it warmed a couple degrees. Tonight, I noticed it should have kicked on when the temp dropped, but it didn't.

Oh, and the furnace is a Lennox G12 series. I don't know how old since it has been here longer than I have, but I'd guess 20 years. Time to replace, I guess, but never had a problem until now.

Anyone know what's up?

It's getting chilly and I might be losing feeling in my extremities...

**Bugeater** · 10-29-2015, 10:59 PM

Gas valve may be sticking, tap on it with the handle of screwdriver.

**Ming the Merciless** · 10-29-2015, 11:05 PM

Quote:

Lennox G12 upflow furnace has a switch that trips periodically
the switch is a thermostat. It is located below the vent where there is an air intake from the front of the furnace to the vent so that it creates an updraft of fresh air to the vent. The only time the thermostat gets hot enough to trip is when the burner first lights before the fan kicks on.

I haven't messed with that model but usually theres a heat switch that you can reset, and it should work fine.

Or maybe the heat switch failed, and needs replaced (easy)

hopefully anyway

if it was working last night, that's my guess

**DaneMcCloud** · 10-29-2015, 11:08 PM

Home ownership can be highly overrated.

I hope the repair/replacement is cost effective for you.

Good luck.

**TribalElder** · 10-29-2015, 11:11 PM

I had a similar problem last year and it was battery deal that helps it starts

Charge was too low

Replaced and worked great after that

Might try taking the cover off and back on to trip the reset if there is one

cosmo20002 · 10-29-2015, 11:22 PM

Quote:

Originally Posted by Baconeater

Gas valve may be sticking, tap on it with the handle of screwdriver.

Read something like that on some message board, so I've been tapping on everything. No luck.

cosmo20002 · 10-29-2015, 11:25 PM

Quote:

Originally Posted by Pawnmower

I haven't messed with that model but usually theres a heat switch that you can reset, and it should work fine.

Or maybe the heat switch failed, and needs replaced (easy)

hopefully anyway

if it was working last night, that's my guess

I saw that reset switch in a manual of a more recent model, but there doesn't seem to be one on mine.

**Ming the Merciless** · 10-29-2015, 11:43 PM

Quote:

Originally Posted by cosmo20002

I saw that reset switch in a manual of a more recent model, but there doesn't seem to be one on mine.

There should be one hmmm.. follow wires from valve area. Sometimes , actually mostly....the reset switch is up higher or away from the pilot&valve. Maybe up by the vent. Should have a wire. Sorry I sound reeruned...on a k I ndle

**Bugeater** · 10-29-2015, 11:43 PM

Quote:

Originally Posted by cosmo20002

Read something like that on some message board, so I've been tapping on everything. No luck.

If you have a meter you can check and see if you're getting the 24V necessary to open the main valve, usually that terminal is marked with MV or M1. If the 24V is there, the gas valve is probably toast. If you don't have it, could either be a bad connection or a bad transformer. Hard to say for sure without getting a meter on everything.

**Ming the Merciless** · 10-29-2015, 11:46 PM

You're pretty sexy when you talk shop

Do you have a multi meter or does it just go one way

BlackHelicopters · 10-29-2015, 11:59 PM

Check the fetzer valve.

ping2000 · 10-30-2015, 12:18 AM

It's a sign. Obama wants you to switch to solar or wind power.

**Bwana** · 10-30-2015, 06:11 AM

A furnace is overrated and it's not even winter yet! A real man would make do by busting up furniture and ripping off chucks of the neighbors fence to start a fire out in the backyard.

Hog's Gone Fishin · 10-30-2015, 06:26 AM

Quote:

Originally Posted by Pawnmower

There should be one hmmm.. follow wires from valve area. Sometimes , actually mostly....the reset switch is up higher or away from the pilot&valve. Maybe up by the vent. Should have a wire. Sorry I sound reeruned...on a k I ndle

This, High limit switch needs reset. Mash the little red button.

Or , check to make sure your valve is turned to the on position. After you light the pilot you have to turn it to "on"

thawk · 10-30-2015, 07:23 AM

Probably a limit switch and it may be in the blower compartment. If it is then you need to figure out why it tripped. Most likely dirty filter. turn power off before you go digging around in blower compartment. If you don't find it easy call a pro. You don't want to make problems bigger than they already are.

10-29-2015, 10:56 PM
cosmo20002 Debunking your bullshit Join Date: Aug 2002 Location: KC area Casino cash: $5220315	Furnace! Furnace ain't working. Pilot light is on, no problem. Bluish flames. But the burners won't ignite. Fusebox is fine. Tried turning everything off and vacuuming out crud and debris. So, when when I change the temp on the wall thermostat to make the heat kick on, nothing happens. If I switch the thermostat setting to "ON" instead of "Auto," the blower kicks on, but since the burners don't ignite, there's no warm air. Llast night I turned on the heat for the first time of the season. Worked fine, and I assume it turned off when it warmed a couple degrees. Tonight, I noticed it should have kicked on when the temp dropped, but it didn't. Oh, and the furnace is a Lennox G12 series. I don't know how old since it has been here longer than I have, but I'd guess 20 years. Time to replace, I guess, but never had a problem until now. Anyone know what's up? It's getting chilly and I might be losing feeling in my extremities...
Posts: 52,592

10-29-2015, 10:59 PM	#2
Bugeater The Maintenance Guy Join Date: Sep 2005 Location: Renovated Bugeater Estate Casino cash: $6252680	Gas valve may be sticking, tap on it with the handle of screwdriver.
Posts: 70,443

10-29-2015, 11:08 PM	#4
DaneMcCloud Supporter Join Date: Sep 2000 Location: Hollywood, CA Casino cash: $10053648	Home ownership can be highly overrated. I hope the repair/replacement is cost effective for you. Good luck.
Posts: 88,960

10-29-2015, 11:11 PM	#5
TribalElder Arrowhead Trail of Tears Join Date: Oct 2012 Location: KansasCity Casino cash: $2440441	I had a similar problem last year and it was battery deal that helps it starts Charge was too low Replaced and worked great after that Might try taking the cover off and back on to trip the reset if there is one
Posts: 29,115

10-29-2015, 11:46 PM	#10
Ming the Merciless Emporer of Mongo Join Date: Apr 2010 Location: Milky Way Casino cash: $2977556	You're pretty sexy when you talk shop Do you have a multi meter or does it just go one way __________________ ---- 2018 Adopt-A-Chief : Chris Conley 2017 Adopt-A-Chief : FRANK ZOMBO Click here-->*The Holy Chiefsplanet Lexicon **
Posts: 44,480

10-29-2015, 11:59 PM	#11
BlackHelicopters Spiraling down the Drain Join Date: Oct 2012 Location: Dante's Ninth Circle Casino cash: $2740588	Check the fetzer valve. __________________ "We're both part of the same hypocrisy, Senator, but never think it applies to my family." "Fredo. You are my brother, and I love you. But never take sides against the Family again. Ever." 2019 Adopt a Chief - Travis Kelce #87
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10-30-2015, 12:18 AM	#12
ping2000 Changes pants while driving Join Date: Nov 2001 Location: Washington D.C. Casino cash: $5930495	It's a sign. Obama wants you to switch to solar or wind power.
Posts: 15,769

10-30-2015, 06:11 AM	#13
Bwana It's Five O'Clock Somewhere Join Date: Aug 2000 Location: Billings, Montana Casino cash: $2139573647	A furnace is overrated and it's not even winter yet! A real man would make do by busting up furniture and ripping off chucks of the neighbors fence to start a fire out in the backyard. __________________ Adventure is dangerous....but monotony can kill you.
Posts: 69,732

10-30-2015, 07:23 AM	#15
thawk Starter Join Date: Nov 2009 Location: everywhere ! Casino cash: $9126783	Probably a limit switch and it may be in the blower compartment. If it is then you need to figure out why it tripped. Most likely dirty filter. turn power off before you go digging around in blower compartment. If you don't find it easy call a pro. You don't want to make problems bigger than they already are.
Posts: 75