motr40
12-24-2007, 09:40 AM
Hey HVAC.. First time on the site. I hope I can get some feedback from on troubleshooting and correcting a problem with my forced air wood furnace controller. It is a Honeywell Fan limit control: Here is a picture and description:
http://www.high-performance-hvac.com/hvac-photos/HVACPhotos/fan-limit-control.html
The controller has moveable tabs on a temperature sensative wheel that allow you to set your "OFF" "ON" and overlimit or overheat "OFF" settings. I have mine set to turn "ON" when the plenum reaches 150 degrees and blow until the plenum temp drops to about 75 degrees then it goes "OFF" . While cleaning the chimney yesterday, I turned power off to the blower and forgot to turn it back on when the cleaning job was complete. :( The wood furnace continued to warm until the plenum reached the 200 degree overheat "OFF" position. I turned the power on after realizing my mistake and the blower turned "ON" and stayed on for a few minutes until the the plenum reached 150 degrees and turned "OFF". Now the furnace cycles "ON" and "OFF" on the 150 degree tab and no longer blows down to the 75 degree tab. It simply cycles "ON" when it reaches 150 degrees and goes "OFF" as soon as it drops below 150 degrees. I need some help getting this thing back to normal. I have an old fan limit control from another furnace, and I have looked at the inside parts, so I know what it is supposed to do. PLEASE HELP.
MOTR
http://www.high-performance-hvac.com/hvac-photos/HVACPhotos/fan-limit-control.html
The controller has moveable tabs on a temperature sensative wheel that allow you to set your "OFF" "ON" and overlimit or overheat "OFF" settings. I have mine set to turn "ON" when the plenum reaches 150 degrees and blow until the plenum temp drops to about 75 degrees then it goes "OFF" . While cleaning the chimney yesterday, I turned power off to the blower and forgot to turn it back on when the cleaning job was complete. :( The wood furnace continued to warm until the plenum reached the 200 degree overheat "OFF" position. I turned the power on after realizing my mistake and the blower turned "ON" and stayed on for a few minutes until the the plenum reached 150 degrees and turned "OFF". Now the furnace cycles "ON" and "OFF" on the 150 degree tab and no longer blows down to the 75 degree tab. It simply cycles "ON" when it reaches 150 degrees and goes "OFF" as soon as it drops below 150 degrees. I need some help getting this thing back to normal. I have an old fan limit control from another furnace, and I have looked at the inside parts, so I know what it is supposed to do. PLEASE HELP.
MOTR