With the heating season fast approaching I decided to test the heat pump. Keep in mind this is brand new construction and we moved in May and AC has been working flawlessly.
I turned on the heat and the outside unit kicked on, but I noticed it’s blowing warm air instead of cold. The low pressure suction line is also cold, should be hot, that much I know. I always had gas furnace for heat before this.
My initial instinct was to contact the builder warranty, but decided to give it some troubleshooting to familiarize myself with the system at the very least.
Checked voltages at the unit, both the Y and O terminals are energized. In heat mode, only Y terminals should be. Playing with the thermostats (nest) didn’t help, everything there is configured correctly.
I removed the O wire from the terminal and we had heat. I was on the right track.
I turned to the zone controller next and noticed that no matter if I called for heat or cooling, the cooling LED was always on.
Found the manual for it and there is a programming section. Entered the programming mode and of course it’s programmed for conventional heating/cooling, not the heat pump mode.
Corrected the mode and now the heating LED was illuminated when heat was called, great!
But we’re not done yet. I was still getting cold air out the vents. Ugh, I’m almost ready to give up, but not just yet.
I start measuring the voltages on the zone controller. The right side connects to the thermostats and the left side to the air handler. I notice that on the thermostat side the O terminals have 0V when heat is called, which is how it’s supposed to be. But on the left side the O is always energized, even if the system is on standby.
This should’ve been a clue, but I’m no HVAC guy and I have no reference point.
So now I’m reading the air handler manual and in it I find that for heat pumps the O and R terminal jumper should be removed. I look inside, and behold, the jumper is there.
I removed the jumper and the O terminal is no longer energized all the time and my heat pump is putting out heat finally.
Holy crap, the trades have gone downhill for sure. And what’s even more troubling is that if more people have it installed this way, their emergency electric strips will be used all the time, resulting in huge electric bills!
I turned on the heat and the outside unit kicked on, but I noticed it’s blowing warm air instead of cold. The low pressure suction line is also cold, should be hot, that much I know. I always had gas furnace for heat before this.
My initial instinct was to contact the builder warranty, but decided to give it some troubleshooting to familiarize myself with the system at the very least.
Checked voltages at the unit, both the Y and O terminals are energized. In heat mode, only Y terminals should be. Playing with the thermostats (nest) didn’t help, everything there is configured correctly.
I removed the O wire from the terminal and we had heat. I was on the right track.
I turned to the zone controller next and noticed that no matter if I called for heat or cooling, the cooling LED was always on.
Found the manual for it and there is a programming section. Entered the programming mode and of course it’s programmed for conventional heating/cooling, not the heat pump mode.
Corrected the mode and now the heating LED was illuminated when heat was called, great!
But we’re not done yet. I was still getting cold air out the vents. Ugh, I’m almost ready to give up, but not just yet.
I start measuring the voltages on the zone controller. The right side connects to the thermostats and the left side to the air handler. I notice that on the thermostat side the O terminals have 0V when heat is called, which is how it’s supposed to be. But on the left side the O is always energized, even if the system is on standby.
This should’ve been a clue, but I’m no HVAC guy and I have no reference point.
So now I’m reading the air handler manual and in it I find that for heat pumps the O and R terminal jumper should be removed. I look inside, and behold, the jumper is there.
I removed the jumper and the O terminal is no longer energized all the time and my heat pump is putting out heat finally.
Holy crap, the trades have gone downhill for sure. And what’s even more troubling is that if more people have it installed this way, their emergency electric strips will be used all the time, resulting in huge electric bills!
