#Carrier fk4dnf002 manual manual#

I'm hoping it's just the reverse valve stuck or whatever temperature sensor is kicking it into defrost mode since the compressor was working fine when it was in the 30s. I can't imagine this is good for the compressor, so I've put it in emergency heat (to stop the compressor from trying to start) and have a service tech coming by later today.

There is no ice on the outside unit or coil. The fan would stay stopped for a few minutes and the process starts over. It would then stop and the unit was making a hissing sound (almost like it was in defrost mode). It was very cold overnight (in the teens) and I noticed that the fan on the outside compressor was starting up and running for about 45 seconds. I was thinking the lower airspeed might be causing it to drop lower more often on cold days, but it looks like I might have a compressor issue. My subjective impression is the Aux heat has been kicking in a bit more than previously, and I wanted to know if this could explain that.Р”В¬orrect, the thermostat automatically engages AUX heat when the temp drops 3 degrees below the set point. I'm asking because when the technician was last here he moved the setting to the comfort setting to slow down the blower (to reduce noise/vibration).

#Carrier fk4dnf002 manual manual#

Is that a correct understanding? The wording in the manual makes it seem like the opposite. The comfort mode reduces the speed so the moving air doesn't create as much of a 'breeze,' but means the compressor isn't being as efficient at heat transfer. Better heat exchange would mean a slightly lower balance point (or shorter runs when not as cold). My understanding is that running at a higher CFM in heating mode will move more heat away from the coils which should allow for better heat exchange. HP-EFF - Provides same airflow for heating and cooling modes approximately 350 CFM per ton Provides approximately 350 CFM per ton cooling airflow for good humidity removal HP-COMFORT - Provides approximately 315 CFM per ton for higher normal heating air delivery temperature. The manual describes the settings as follows:

My heat pump controller board has a setting for Comfort or Efficiency mode to control the speed of the motor.