I had a 3.5 ton Trane XR15 heat pump installed last April. The unit replaced a 2002 Lennox 3.5 ton air conditioner (don't know the exact model number). The HVAC company did do a proper load calculation and said we were fine with 3.5 tons. The unit has performed flawlessly in COOL mode, but it seems to perform kinda weird in HEAT mode.
The unit heats and cools the main level of my house, and the main level is about 2200 sq ft. It is matched up with a 2002 Lennox G40 90,000 BTU input gas furnace with a 4 ton blower. So, the whole system is a dual fuel system.
I turned the heat on this morning and while it was running the heat pump outside turned off for a few seconds then turned back on. Then about a minute later it did the exact same thing. The blower stayed on the whole time and the thermostat still said "heat on". After a few minutes the heat pump turned off again for a few seconds and then back on, and it kept doing it repeatedly until the heat cycle ended.
Could this lead to anything bigger in the future? Is there something wrong with the unit? The unit doesn't do this at all in cooling mode.