Air conditioning no cold air

rocklobster

Well-known member
Joined
Oct 8, 2017
Messages
102
Fluid Motion Model
R-21 EC
My AC on 2019 C28 run but doesn't have cold air. Pumps water well (I can see it shoot out side of boat). Fan runs fine. Setpoint set for cold air. Unit just blow room temp air.

Where is the unit located by the way! ?

Joe
 
Air unit is in the cave Port side forward. You will see the Teak grill for the intake. The intake has a filter but there is no plenum between the intake and the actual air unit so the main filter that is mounted infront of the coils can get dirty and reduce air flow causing icing. There is a programed deicing mode that you can set. What I do is put the unit in heat mode for a few minutes then switch back to cool mode. See if this resolves your issue. If not use the owners manual to preform the troubleshooting procedures. Normally the sequence of operation is cool selected, pump starts, compressor starts , air mover (fan) turns on and operates in the setting selected Auto or Fan speed. Cool air should start to blow. I have had the unit ice up a few times and warm air is then felt.
 
rocklobster":33rzrpi7 said:
My AC on 2019 C28 run but doesn't have cold air. Pumps water well (I can see it shoot out side of boat). Fan runs fine. Setpoint set for cold air. Unit just blow room temp air.

Where is the unit located by the way! ?

Joe

Hey Joe,

This may require to have the unit inspected to make sure there isn't a leak in the system not allowing it to cool. Also, does the heat side work?

Thanks,
 
Not related to Rock's A/C issue but we just relaunched our "new to us" 2019 C-28 and turned the A/C on. Turned on just fine but after a couple minutes, the overheat screen came on. Turned it off and then back on again and looked over the side to see if the cooling water was flowing. Nope.

A few moments of thinking, so I opened the engine hatch and took a look at the clear plastic sea water strainer, no water flowing.

Removed the top, poured some water into the housing, closed it back up, turned the A/C back on and after a couple burps, plenty of water flowing out the side. The strainer/pump had lost its prime while the boat was up.

Just thought that I'd pass this little (duh!) tid-bit along...

Bob/Bradenton
 
Bob, the issue that you described is a common issue with Cutwaters and Ranger Tugs. Reason: the water pumps for air units are not self priming. The pumps are designed to be located below the water line. Fluid Motion never read this portion of the installation manual:


This is quoted from the Dometic installation manual. and is in every Marine Air Unit manual.
" Centrifugal pumps are not self-priming, and must be mounted so that they are below the heeled waterline in any given operating condition. The pump should be accessible for future service.
Mount the pump so the outlet is directed upward so air can escape. The head on some pumps can be rotated to allow mounting on a vertical bulkhead. See Figure 9.
Self-priming pumps are available if the pump cannot be mounted below the waterline."

The installation of the pump is above the water line but the pump used is to be mounted below the water line. The Fluid motion fix for the improperly installed pump is keep you seacock closed and leave all the sea critters in the system when the boat is lifted and stored or prime the system every time you launch the boat. The proper fix is mount the pump below the water line or install a self priming pump. I had this issue in 2016 I thought they would have resolved it by 2019! If it doesn't work right maybe we should fix it :shock: ? Or maybe Not !
 
Well, if the water is flowing from the outlet then you know the water pump is working properly. Do you hear the condenser kicking in? Is your issue when you first start the A/C or after it has been running? If after running it could be that the coil is freezing. As mentioned you should have the deice feature programed to avoid this.
 
By the way, if you are concerned that the condenser turned ON or not (and you can't hear it but the pump is running), just take a look at the AC Amp gauge when you hit the A/C ON button. The pump comes on first with almost no Amp draw at all, but when the condenser kicks ON, a huge needle swing to the right, over 40 amps for start-up. For just a moment but that will tell you that it turned ON. And then will register somewhere around 10-12 amps while the condenser is running. When turning the A/C system OFF, be sure to leave the circuit breaker ON for about 10 seconds before flipping it OFF. The pump continues to run for a couple seconds after you turn the A/C control panel button OFF. Let it turn OFF on its own, then turn the breaker OFF.
 
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