420 Passage Forward A/C fan counts down from 6 wont cool

[tootssea]

our forward A/C just stopped cooling. We were in a marina and both worked just fine. Checked into another marina and the forwardA/C gives an HPF error and continues to count from 6 to 1, and then starts over again. Thre fan runs while its counting but no cooling. Strainer is clear, no obstruction to unit. Nothing changed from first marina to second marina. Rear A/C works great and discharge flow is great. Ideas.

 

[uncledom]

discharge flow on the forward unit is ok too. It uses the same pump I'm sure but there could be a clog in the line going to the forward unit. My unit usually says HPF on cooling flow.

 

[JamesG161]

HPF error

Is High Pressure switch.
Possibilities..
1) Return Air filter Dirty
2) Dirty water cooled exchanger.
3) You may need a new "Hard Start" or temperature controlled Start Capacitor.

If yours is MarineAirr... like mine, I would bet it is #3.

The fan will run 24/7 per design. You must turn off all power to the unit for 30 seconds to allow the Controller to reset. I would turn off the back unit to allow Max Amps to start the compressor.
If your unit fails to start and you still get HPF error, you may have a bad Pressure switch or lose wire.

I keep my exchanger clean by using a Bromine Spa Tablet in the intake strainer basket. MarineAirr uses the same Copper/Nickel metal used in Spa heaters.
Jim...