Duo Therm Penguin heat pump feature

[Silverleaf]

We have a 1997 Excella 30' Classic. It has only one AC unit, and I think it is original. The thermostat lists heat pump as one of the options when I cycle through the modes, but the heat pump setting doesn't appear to do anything. How can I prove that I actually have the heat pump feature? Could it be in the list but not actually installed? I've tried it in cool but not below 40* temps, so it should work. I don't expect the compressor to kick on, but I would expect to hear the fan. Any one have experience with this?

[Al and Missy]

Whether or not heat pump shows up on the thermostat is, I think, controlled by dip switches in the control board in the inside unit. If that was set wrong, or if the overhead unit was changed and controller not reconfigured, it may be showing Heat Pump even if your unit doesn't support that feature.

I suspect the only way you can find out for sure is to remove the cover from the rooftop unit and read the label to get the model number. An AC tech could probably look at it and spot the reversing valve, and maybe you can. I wanted to find out what size unit was in my trailer but there was no label for the roof-mounted part visible even after removing the shroud from the inside.

Al

[Ohiobrits]

As Al said, pop the cover off the unit (4 Large screws, 2 along the front edge one each side). There will be a wiring diagram on the right side towards the front on the electronics box lid. If it shows a "reversing valve" your unit is a heat pump. The reversing valve does just what it sounds like, reverses the operation of the unit to either move heat from the inside of the coach out (A/C or cooling mode) or move heat from the outside in (heat pump mode).

Below is a photo with cover off. White wiring diagram is located towards the front. The reversing valve is shown on the wiring diagram towards the right at the bottom.