could be a few things.
if this doesn't work. i came across others where the building was in a bad negative and the inducer blower motor could not overcome the negative pressure
Need help troubleshooting my Lennox G23 furnace. When on Auto it starts up, pilots ignite but as soon as it heats up getting ready to turn the blower fan on it shuts completly down, even our digital thermostat goes completly blank like the battery is dead. (which we replaced so it is new) We can get it to run by doing this: reset the thermostat or flip the power switch on the furnace, turn on the heat on auto, once it gets to the point its about to kick the blower motor on we turn the fan to "on". Troubleshooting so far has consisted of: cleaned ignitor, new thermostat battery, took the red wire and white wire on the thermostat and hooked together but still shuts off when blower gets ready to come on, checked that there was no loose wires. Please anyone have any ideas?
could be a few things.
if this doesn't work. i came across others where the building was in a bad negative and the inducer blower motor could not overcome the negative pressure
Last edited by beenthere; 12-01-2010 at 05:25 PM. Reason: removed DIy diagnostic check list
It could be many different things. Most likely the control board/blower timing. However, this is not a fix that you want to guess on. These boards are expensive and cannot be returned once opened. Do yourself a favor and call a reputable service company.
Wisdom has been chasing you, but you have always been faster.
In your darkest hour, when the demons come, call on me brother and we shall fight them together.
A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii
Since the furnace works fine when you turn the blower fan on manually, there could be a problem with the thermostatic switch that turns on the blower when temperature gets high enough. The reason everything is shutting off is for safety, the high limit safety (temperature too high) opens off all the control power and the gas shuts off. If there is not something simple that you can fix easily, please call a pro, the safety features are not to be trifled with.
We had 2 home explosions here in Edmonton this year, one was a DIY gas furnace fellow who thought he had the "right stuff" and subsequently removed himself from the gene pool...
Wisdom has been chasing you, but you have always been faster.
In your darkest hour, when the demons come, call on me brother and we shall fight them together.
A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii
We had the ignition control box replaced in Feb 2010, just noticed they put on a Honeywell brand---could this make a difference?
The brand shouldn't make much of a difference, provided it is the correct replacement board and was installed/wired correctly. There is another circuit board (I think) in the blower compartment that actually controls blower operation.
Wisdom has been chasing you, but you have always been faster.
In your darkest hour, when the demons come, call on me brother and we shall fight them together.
A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii
Ok thanks everyone my husband is checking everything everyone has posted. I will let you know!!
Ok guys how can we tell if our limit switch is bad?
At this point, I can only refer you to the site rules. Do it yourself advice is not allowed on this site. You are dealing with a safety control and do not know what you are doing. Call a pro.
Wisdom has been chasing you, but you have always been faster.
In your darkest hour, when the demons come, call on me brother and we shall fight them together.
A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii
You are correct, the G23 has a circuit board in the blower compartment, and blower is timer initiated, not via temperature. If down to this please get a pro in to check this out, circuit board repair is a manufacturer task, after field replacement.
The other one of those natural gas explosions here took out most of a whole city block (that was a homicide case though)...