Response from Dometic...
1) There will always be 3 clicks from the control box (or upper unit if board is pre-installed) when operating heat pump. The first click will be 5 seconds after heat pump mode is selected for FAN if in HI, MED, or LOW. Note: On older models MED fan speed was not available. So, the first click is for the fan relay. The 2nd click is to energize (or de-energize) the reversing valve relay which controls the flow of refrigerant. The 3rd click is for the compressor relay which turns the compressor on to start pumping refrigerant. If the fan is in the AUTO position - meaning the fan won't come on until the compressor comes on - then all 3 of the clicks will happen at roughly the same time (within 15 seconds). This is normal.
2) The second complaint listed below about the unit stuttering could be that they are trying to operate the heat pump out of the normal range of operation (on the high side). The heat pump works great in the range of 40-60 F outdoor temperature. In temperatures above 60F (let's say, 70 F) this the compressor could potentially overload and shut itself down. Running on HIGH fan will help avoid this condition by maximizing heat transfer across the coils. Also, make sure the indoor filter is clean and not blocking air flow.
On the low side of the temperature range the compressor will run below 40F down to 30F in defrost mode - which means 25 minutes heating and 5 minutes defrost (fan runs, no compressor). Defrost mode will be indicated on the thermostat.
PLEASE do not send questions via Private Message, my inbox fills up too quickly. Post questions in the forum as a new thread so that other users can benefit from the answers. Use Private Messages for sensitive information only (VIN, Contact info or things you do not want the public to see).