C42 water cooling
This is one of the most misunderstood areas of marine refrigeration. The water pump should only be run when the ambient temperature at the compressor is 100 degrees or more. Below this temperature, you do not get rid of any more heat with the water than you would with the air. BUT!, because you are drawing an extra amp for the pump, it is actually less efficient to run it at lower tempseratures. The pump also should not be run at dockside. There is the chance of getting a baggie or other floating debris against the intake. This would cause the pump to run dry requiring a repair kit. When at dockside, plugged into shore power with the charger running, it is usually not a concern to save a couple of amps. The pump can be reprimed if needed by closing the thru-hull, removing the pump outlet hose and filling the wet end with water, purging any air in the process.
