Most heatpumps have reversing valve energized in cooling mode. I think only rheem has it energized for heating.

Retail stat probably can't do two stage heatpump with aux heat, only two stage conventional a/c.

If your old t-stat only one Y wire connected, not two -> Y1 and Y2, it's a single stage heatpump.

 

That thermostat is can can only do heat pumps that have no aux heat. Do you have aux heat. If so, you need a different thermostat.

 

The manual does say that it can handle one stage and aux heat for the RTH5160 Series.

https://www.honeywellstore.com/store/images/pdf/rth5160-honeywell-thermostat-manual.pdf

Cheers!

 

I must have looked at the wrong manual. Sorry bout that.