|This is the fan limit switch at the cabin. Honeywell L4064B. Moving the two lower pointers farther apart should reduce short cycling.|
I spent the night before opening-day of firearm season at the cabin.
The furnace was short-cycling.
Today I put in a new thermostat. I did not think that was the cause but it was easy and it needed replacing because it was a mercury switch thermostat.
Honeywell makes a $25 unit that is an exact match for the one that came off the wall.
The fan is still short-cycling.
Potential causes include:
- Clogged ductwork (think Red Squirrels here, folks)
- Clogged air filter
- Not enough ducting (the ducts in 2/3 of the rooms were shut off so this might be a player)
- Excessively cold return air (don't know where return air ducts are, perhaps in the shutoff rooms that are not heated or the unheated crawl-space beneath the cabin)
- Defective temperature limit switches
- Improper limits set on the limit switches. This is a possibility. I will move the Fan Shutoff to the low limit and see if this helps.
- Holes rusted in ductwork and/or drain features plugged. (Suggested by an email friend who often chooses to be anonymous.)
|I need to find a manual for this unit so I can figure out where the air filter is.|