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rdaly 03-14-2014 08:05 PM

Heat Pump Lock Out
Hello, This past fall I had an Amana ASZ14 Heat Pump installed. I already had an Amana Propane Heater installed a couple of years ago to replace my original propane heater. My old AC unit just went so my HVAC guy suggested a Heat Pump. I thought that was a good idea. I would use the heat pump for heat above 35 degrees and Propane as the auxiliary heat below 35 Degrees. I have a Honeywell Vision Pro 1AQ Thermostat and the default lock out is set at 40 degrees. I re- programmed it to 35 degrees. Every so often, like today. it is 45 degrees out (it says so on the thermostat) and yet the auxiliary heat (propane) is coming on. Why is that? This happens every once in a while. I asked my HVAC guy (who installed it), why this is happening. He said it might be in defrost mode? Maybe a few weeks ago when we had some frigid temps but not now. What do you think is going on? Should I have something checked out on this? Thanks for your helpl

beenthere 03-15-2014 05:21 AM

Do you have 2 droop enabled? If so, are you setting temp back and when it goes into recovery is it going to the furnace.

hvactech126 03-15-2014 07:55 AM

You can also set an aux lockout with that thermostat.....

rdaly 03-15-2014 04:18 PM

Thanks guys for your help.
Yes, The Droop Temperature is set at 2 which is the default. I still don't understand that totally, in relationship to the recovery mode. But thanks for that information, now I'm studying that more. I manually move the temp settings up and down. I don't have them programmed for certain times / days.

Yes, I know that I have an aux lockout. I set that at 35. (default was 40)

Thanks again.

beenthere 03-15-2014 04:41 PM

Then its going to use the furnace every time you raise the temp by 2 or more degrees. Disable 2 degree droop.

hvactech126 03-15-2014 05:16 PM

Aux lockout is different from balance point.

rdaly 03-16-2014 08:54 AM

Thanks Again! More Questions?
beenthere & HVACTECH126: In my Honeywell Installation Guide: Under the programming section. Looks like there are a few programs that have to deal with "Droop" or are affected by it.

Setup # 0345 / Dual Fuel Heat Pump Control:
1 - Droop Control ** (default)
0 - No Droop Control **
2 - Droop Control with Aux Heat Lockout **

Setup #0346 Dual fuel heat pump upstage to furnace timer (in hours):
1 - 1 Hour** (default)
0 - Off (other options: 0.5, 1.5, 2-6, 8, 10, 12, 14, 16 hours)

Setup # 0347 Droop temperature:
2 - Default (other options: 2 to 5 degree F)

Setup #0350 Heat pump compressor lockout:
40 - Default (other options: 5 to 60 degree F)
I reprogrammed this to 35.
HVACTECH 126 - Special Function section (**) in my Honeywell Install Guide: Looks like they are calling the compressor lockout the same thing as balance point. See below:

**(Special function)
Heat Pump Control - Fossil Fuel Backup (Setup Function 0345):
Option 0 (No Droop Control): If outdoor temp is above balance point (Function 0350), only the compressor operates. Below this temp, only backup heat operates.
Option 1 (Droop Control): As above, but backup heat is activated if room temp drops to the selected droop temp setting (compressor is deactivated)
Option 2: (Droop Control with Aux Heat lockout): Compressor works only above auxiliary lockout temp, backup heat works only below balance point, 2 degree droop between temperatures.
If temperature is not reached in a reasonable time, set the upstage timer (Function 0346). After the designated time, the compressor will be deactivated and the system will switch to backup heat.

So do you think that i what is happening? I am putting the temp setting up to high for it to reach within an hour, so the propane (back up heat) kicks in?

So what exactly should I pick / setup, What you think would be best?
Thanks again for explaining this to me.

beenthere 03-16-2014 09:03 AM

Set droop control to 0, no droop control.

Set upstage timer to 0, Off. Its a waste of propane most of the time.

Set compressor lock out to 30, or lower, to see at what temp the heat pump really can't handle the load. Then raise to temp it can handle the load.

rdaly 03-16-2014 05:31 PM

Thanks Again! Will Do
Thanks beenthere.
I will put in those adjustments and then see how the unit handles 30 degrees. I'm trying to use the heat pump more then propane.

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