- Ecobee thermostat
- Lennox setup (furnace, heat pump, indoor coils)
- Installed for ~6-7 months now
Setting the Ecobee to Heat for 66F (not aux - just using the heat pump) turns on the heat pump and for ~5-10 minutes I get warm air through the vents in the house (72-73F air temp as measured by a laser thermometer). The unit outside has the fan spinning and all seems to be going great. I can also hear a sound from the indoor coils (located below the furnace) as if it's a refrigerator running, so assuming things are normal. Also, one of the connection valves (the one out of which I have a black insulated pipe going out) at the bottom of the outdoor unit reach ~130F (also measured with laser thermometer).
Once 5-10 minutes elapse, I can see that the outdoor unit fan is still spinning, but now the vents in my house register ~59-61F, effectively cooling the house more than actually heating it. The valve I am talking about above now went from ~130F to ~45-50F. The indoor coils no longer make the refrigerator-like noise, but the fan in the furnace is still working.
The Lennox diagnostic codes (LEDs inside the furnace) show
A1600, meaning that likely:
E312- restricted airflow. I replaced the filter, but the problem is still there. Tech on the phone said not to worry about that if I replaced the filter.
C2- cooling stage 2.
A1600- fan operating at 1600 CFM.
After ~20 minutes of blowing ~59-60F air through the vents, the temperature starts to gradually go up to ~62-63F (also through the vents).
NOTE: What I noticed is that overnight the outdoor unit stopped spinning altogether while the fan from the furnace was still blowing cold air. Setting Heat from Ecobee now had no effect at all (outdoor unit doesn't come on) while the fan was still working. Power cycling the house (turn off at fusebox) allowed me to re-start the outdoor unit (likely in lockout state - haven't verified).
What could be causing this issue? What can I do to diagnose the issue before calling a tech?