The top of the compressor should be cool to slightly warm to the touch. Check for adequate water flow. To check the condenser to see if it has a problem,put your hand on the lines to the water-cooled condenser. One side will be extremely hot and the other side should be 100-120 . If both lines are hot, this indicates that the condenser may need cleaning.
Muriatic acid is used in swimming pools and can be found in most hardware stores.
This checks for stuck reversing valves or an overcharged system. Note,in a warm cabin 75 or higher some controls will not go into heat, which is normal. After the system has been in operation for some time, check the black foam piping insulation. Be sure that it fully covers the line and that there is no visible condensation. Inspect the sea strainer, be sure that it is clean, that the baskets are in good condition, the gasket is in good condition and that it has a good seal.