How do heat pumps work?

[pduggs]

I have yet to get my AC units to run on the heat pump setting. I have tried several times and reviewed my manual, but they never come on. All three work well on the AC setting. Is there some kind of trick to getting them to work?

[lwmcguire]

On some thermostats you have to select electric heat

[cavie]

Originally Posted by pduggs

I have yet to get my AC units to run on the heat pump setting. I have tried several times and reviewed my manual, but they never come on. All three work well on the AC setting. Is there some kind of trick to getting them to work?

No trick. A heat pump is the A/C compressor running with the gas running in reverse. It uses a reversing valve. The evaporator and condenser are swapped.

Set to heat and turn up the temp. Compressor runs in A/C and Heat.

[96 Wideglide]

Only thing I can think of is the other zones on the thermostat need to be either off, 'fan only' or 'Heatpump' mode. Won't work if you have another zone set to A/C or Furnace.
Are you giving it a few minutes to start blowing warm air after the compressor starts?

[pduggs]

Originally Posted by lwmcguire

On some thermostats you have to select electric heat

I don’t have that option on my thermostat. I have tried running it on 50 amp and when running the genset. In both instances, the heat pump doesn’t run.

[96 Wideglide]

Doesn't start at all, or, doesn't put out heat?

[HJLowell]

Maybe you have cooling ? Only.
No heat strip, electric ?

Maybe you have the wrong thermostat?

[96 Wideglide]

It's an 08' Dynasty. It came with 3 rooftop Heatpumps.

No electric heatstrips.

[firedoc]

To be sure;
1. Turn switch to heat.
2. Run thermostat to at least 5 degrees above current room temperature.
3. Fan should come on shortly
4. First you will get cold air blowing. It should gradually build up to warm air (not necessarily hot air).
5. Measure temperature of air coming out of outlets and compare with temp of air at inlet.
6. Is outlet warmer than inlet. The
7. If yes unit is
working as designed.
8. If not have unit checked.


You will not have as warm of air from heat pump as from furnace and it takes longer to warm up.

[pduggs]

Originally Posted by 96 Wideglide

Doesn't start at all, or, doesn't put out heat?

It doesn’t start at all. I will check to make sure the other zones are set to heat pump or off.

[pduggs]

Originally Posted by firedoc

To be sure;
1. Turn switch to heat.
2. Run thermostat to at least 5 degrees above current room temperature.
3. Fan should come on shortly
4. First you will get cold air blowing. It should gradually build up to warm air (not necessarily hot air).
5. Measure temperature of air coming out of outlets and compare with temp of air at inlet.
6. Is outlet warmer than inlet. The
7. If yes unit is
working as designed.
8. If not have unit checked.


You will not have as warm of air from heat pump as from furnace and it takes longer to warm up.

Thanks I will try that.

[pduggs]

Originally Posted by 96 Wideglide

It's an 08' Dynasty. It came with 3 rooftop Heatpumps.

No electric heatstrips.

Yes I have three AC units. I don’t believe all three are heat pumps.

[Ron Postma]

When you try to turn the heat pump on does the gas furnace come on? Some systems if the thermostat is set to too high above the indoor temp the gas furnace will come on till the temp comes up to between 2-3 degrees of inside temp. Then the system will switch from gas to electric. Also some heat pumps will not come on if the outside temp is too low.

[pduggs]

Originally Posted by Ron Postma

When you try to turn the heat pump on does the gas furnace come on? Some systems if the thermostat is set to too high above the indoor temp the gas furnace will come on till the temp comes up to between 2-3 degrees of inside temp. Then the system will switch from gas to electric. Also some heat pumps will not come on if the outside temp is too low.

It has the aqua hot.