*This article pertains to all Applied Comfort units with a working display.*
“LO” Designates the room freeze protection that is designed into the control board. This feature will automatically turn on the heat if the indoor sensor reads a temperature below 7 degrees C so that indoor piping does not freeze (even if the unit is off). During the “LO” operation there will be no control of the unit until the indoor space reaches approximately 10 Degrees C.
Possible causes
Leaks around the sleeve allow cold outdoor air to leak into the room causing a fake reading (most likely)
- Open window near the unit ( many people do this in bedrooms at night)
- Indoor and outdoor thermistors are connected incorrectly or damaged
- Faulty board logic in the control board has been corrupted.
Corrective measures.
- Ensure no leakage sleeve to wall and unit to sleeve if the seals or calking is damaged or missing replace them so there is no penetration of cold outdoor air
- Close windows at night / Or disable the feature by changing DIP switch #5 off. Keep in mind this overrides the safety so if there is water piping nearby it is not recommended.
- Check thermistors for correct connection to the board and insure no damage to the insulation
- If all others check out replace the board.