Turn the thermostat up until the unit comes on if your heat pump is not running and you have a mechanical thermostat control. It may not be turned up high enough. Make sure the 5-minute delay has passed if the delay timer is still running. You may have low water, so make sure the filter pump is on and unhook all cleaning devices. Check the outside temperature to make sure it is not too low. If it is, you will need to wait for a warmer temperature.
Adjust the thermostat for higher heating temperatures if the heat pump is running but not heating. If this does not work, your fan or system component may not be working. If this is the case, you will need to call in a technician to work on your unit.
Turn the thermostat down if the heat pump runs continually. If this does not solve your problem, turn off the filter pump. If the unit still runs after 2 minutes, turn off the power to the unit. This means there is an electrical component failure, and you will need to call in a technician.
Check the valve settings to make sure water is flowing sufficiently if the heat pump is cycling on and off too quickly. If it continues to cycle, turn off the unit so that you do not damage the compressor. You may also have low refrigerant, a low outside temperature or high humidity with a low temperature. Ensure that there is no frost on the evaporator coil.
Turn off the heater for a minimum of 2 hours if there is water coming from the bottom of the unit. Make sure, though, to leave the filter pump running continuously. If the water evaporates on its own, then it was only condensation, which is normal and nothing to worry about. If it is still there, then you may have a leak and will need to call in a technician.