Reverse cycle air con systems of all varieties should and usually do have a de-icing device. This is simply a thermostat that monitors the condenser temperature so that when in
heating mode, (and the condenser becomes the evaporator) if the temperature lowers to where it causes frost restricting air flow or in this case ice restricting water flow, the indoor air distribution fan is switched off and the system refrigerant flow is reversed from
heating to
cooling for several minutes. This sends a rush of heat to clear the evaporator, then once clear this thermostat reverts the system back to normal operation.
Now I have no experience with this brand but it doesn't appear to have this otherwise common protection.
This de-ice control could be added via a digital thermostat and double pole relay and some
wiring.
The digital controller's thermistor (sensor) would need to be located in the most sensitive spot where frost / ice build up occurs. This thermostat would simply supply/ switch the relay. The relay would do nothing until the thermostat switches at say +35F (2C) when it would be activated. At that time the relay would disconnect
power supply to the indoor fan and switch the reversing valve. This would cause the indoor fan to stop and the system reversing valve to reverse the refrigerant flow causing defrost / de-icing. Once clear of frost / ice the thermostat would sense the temperature rise and revert back to normal status.
Seems complicated but really quite simple, although a bit a tweaking the thermostats cut in and cut out points would be needed. But once done there would be no more frost over or ice up.
Regardless of having a de-ice control or not, the flow of heat, in this case via water, is critical.
Cheers OzePete
Ozefridge | 12 Volt Refrigeration Systems