air conditioning issue 2018 RT CB 31

[Marnis]

I have an intermittent problem with the main salon AC. I start the AC and there may be a 10 degree differential in temp and it starts up giving cold air. It may run for a half hour or more with the temp slowly dropping then the compressor shuts down and air stops blowing. The AC control panel will then show the current boat temp, which will still be at least 7 degrees higher than the set temp. Turning the unit off at the control panel and then restarting it, you hear the compressor trying to start and then turn off and the control panel once again stays on displaying the current temp. The next step is turning the breaker to the AC unit off and then on. At this point I turn on the AC and everything functions normally and the unit cycles normally. Any thoughts?

Marnis

 

[BB marine]

I had the same issue a couple weeks ago. It was a unusually warm day in Wisconsin low 90's. I keep the fan set on constant run. I was loading a couple of routes into the Garmin which is right across from the main air discharge. The fan shut off. I thought a breaker had opened. I checked the controller and it showed the temp. I shut it off and the turned it back on I heard the pump kick on then the compressor but no fan and the the compressor shut down. I went thru a few troubleshooting steps, I did a factory reset, shut the unit down and power shut down is part of the reset. Turned breaker back on turned unit on and it worked. I called Marine Air and talked to a technician. He said most likely the Triac on Passport I/O circuit board is failing. He gave me some troubleshooting steps and explained how to by pass it if it failed so I can still use the Air while I wait for the new board to arrive. Approx $350.00 for the board. I attempted to do the troubleshoot but the control box is buried behind the air unit so I could not reach it without removing the complete system. This will be another project for the winter to remove the Compressor relocate the electrical box so it is accessible and reroute the air units discharge vent hoses properly so more air goes into the interior of the boat and not into the nonliving space compartment. On a warm day you can see the hull sweating where the compressor is. There is a lot of cool air escaping between the bulkheads and hull.

 

[Steeldieman]

Man , I would pay you to work on my boat

 

[knotflying]

Did you check your settings? There is a cycle that defrosts the condenser coil and your symptoms sound similar. The cycle is designed to shut sown the unit and then the system goes briefly into reverse mode and heats the coil to melt any ice build up. This will happen more frequently when it is an extra hot and humid day and when the system is first trying to cool the cabin.

 

[BB marine]

Did you check your settings? There is a cycle that defrosts the condenser coil and your symptoms sound similar. The cycle is designed to shut sown the unit and then the system goes briefly into reverse mode and heats the coil to melt any ice build up. This will happen more frequently when it is an extra hot and humid day and when the system is first trying to cool the cabin.

Knotflying could be correct if your compressor continues to run, fan turns off and and reversing valve energized ( compressor still runs). This can be programed ,off , 1 minute, 2 minute or three minute intervals to de-ice the evaporator coil. This can be set up in P8 program number. On my unit it goes thru a "preventative" defrost mode This is accomplished by short compressor shutdown periods combined with a one-speed increase in fan speed, and by periodic Heat Mode cycles with the fan turned off. This happens in a short period of time. If you had symptoms like this you also may have experienced defrost. I would question it being defrost mode if the compressor and Fan continually are not operating for long period of time. This is what my experience was. No fan, no compressor, turn unit off then on Pump kicks on, compressor kicks on, no fan, compressor kicks off. I spent a bit of time trouble shooting. I went to P17 return to factory defaults shut power down and turned power on ,reset my default functions to my liking. Turned unit on it functioned properly. I did ask the technician if he thought I was in a defrost mode. He responded with a no. I would go with Knotiflying suggestion , Check your default settings if all is good no issue. If you experience it again maybe the Triac.

 

[bill46]

Yours is probably too new, but we found filers behind the wall mounted ones right on the evaporator, clogged with lint on both. Works much better clean. Plan to replace the course metel mesh with finer foam or fiberglass type since second ones are quite hard to reach.