Reverse Cycle heating can be very efficient at warming a space as the air con unit will circulate the cabin air very quickly warming the space with dry odour free air. The air con unit in reverse cycle generates the heat from a mix of compressed refrigerant and heat in the sea water so there are limitations based on the sea water temperature. This limit is about 8 degrees c so it is not always an all year heating option.

No. Heating ducting and air con ducting have differences in ducting type and locations. Heating ducts are often placed low in a space as heat rises and designed to take dry hot air. A/C ducting is larger to allow cabin air to circulate quickly from low to high. The ducting is also insulated to discourage condensation build up on the cold pipes.

Air con units work by circulating the cabin air and a small unit will not have the ability to move enough air in the cabin resulting in no cabin temperature change. The unit must be the correct size for the space.   

This alarm in cooling mode is due to a lack of cooling water being circulated through the air con unit. You should inspect the weed strainer for blockages and ensure water is flowing quickly out the water discharge overboard. The most common cause of this is an air lock between the sea water pump and the air con unit. An easy way to release the air lock is to carefully remove the water inlet hose from the air con unit. The water inlet hose will be the lower hose on the air con’s exchanger and should only be done when the unit is switched off. As you remove the hose, you will often hear the air escape and the sea water will flow. The power supply may need to be briefly switched off to reset the fault.

This alarm is often related to sea water temperature being too low. It can also be poor sea water circulation so you should check the weed strainer for blockages and ensure you have water flowing quickly out the water discharge overboard. The air con unit requires the sea water temperature to be above 8 degrees C to operate correctly in heating mode.

Noise and vibration is an indication of poor water flow and trapped air. The water hoses should be gradually inclining from the water inlet to the water discharge overboard. Rise and falls of the cooling the hoses can lead to air getting trapped in the lines so careful routing of the hoses is essential.