Heatpump vs propane furnace cycling

blangen wrote:

dougrainer wrote:
When you have ONE tstat that controls both roof AC/HP and the furnace, there are NO separate tstats for the Furnace and the roof AC/HP. They utilize the same tstat sensor.
Since Carrier was not in the RV business that long, I have little experience with them. Is it possible that unlike other brand systems, you have to set the Furnace Temp separate from the HP temp on the remote? Even tho you are going to the default when it gets too cold? Doug

The tstat is a wireless remote and, yes, it controls everything. There are separate settings for each "MODE" setting. When in "FURN" mode, one can set the desired temp. When in "HEAT" mode, one can set a different temp (or the same). It is in "HEAT" mode that the heat pump runs until it gets too cold then the furnace kicks in... and that's when the temperature in the coach just runs up. In "FURN" mode, it cycles properly. What's interesting is that all of the controls are in the heat pump/AC unit on the roof because, even in just "FURN" mode, the remote needs to be pointed toward the roof unit to work and that's where the relays are heard.

What I think is happening is there are two temp sensors, one in the roof unit and one in the location of the furnace (under the kitchen cabinet). When in "HEAT" mode, even when it switches to the furnace, it uses the sensor in the roof unit (where it is colder). When in "FURN" mode, it uses the sensor located in the furnace on the floor. I don't KNOW this to be true but it seems like the reasonable answer. Also, rgatijnet1 (above) said he had two sensors. My original question was is there a way to fix this... so I didn't have to get up in the middle of the night to change from heat pump to furnace. Frankly, I don't really mind but I'd like to avoid the dirty looks from my wife when we wake up cooking. (Mostly kidding about the dirty looks) :) Anyway... unless someone pipes up with a mechanical fix, I guess we'll just have to call this a design flaw. I'd love for someone to say there's a set screw to adjust something but that's just wishful thinking, I guess. Heck, if we're wishing, maybe I should just wish for a new coach with aqua-hot! lol