My a/c units are acting up, I'm...

[A_Lot_More_Misc]

My a/c units are acting up, I'm getting a PS HI error, which should mean I'm not getting enough flow, Cleaned out the filter and opened and closed the seacock to increase the flow coming in, also cleaned both units and the condensors. Now it seems that the rear salon unit is working, but once the forward unit kicks in, they both stop, however, they both work just fine when they are set to heat. (it got kind of cold overnight this weekend) 

Any ideas would be really appreciated.

[Jet_Rooster]

If you are in saltwater, the units probably need to be serviced. This includes cleaning the air filters and the seawater plumbing. Marine growth can obstruct the small lines and the lack of flow causes the PS HI error. That's what happened to mine anyway.

[A_Lot_More_Misc]

Thank you, but no, I'm in fresh water, although I do suppose the same could occur. One of the other solutions I read was to take the boat for a good run, the weather has been pretty crappy here lately and the boat hasn't been for a good run in a month or so.....

[BamBaLam]

Living in Florida and in a marina with a lot of 'funk' in the water, I've become a lot more knowledgeable with our A/Cs than I ever intended. Based on what you've done so far, it sounds like you need a professional to find the line blockage - may need an acid flush. With our conditions, we're doing an acid flush twice a year, and cleaning strainers weekly.

[SMT]

Check you condenser and evaporator make sure they are clean. A piece of plastic or just dust/pet hair has built up can create enough of a blockage to raise the pressure. I have seen plastic wrap sucked up and pet hair block an evaporator that will also cause high pressure and shut a system down. I flush my water system a couple times a year with Ridlyme or Barnicle Buster. I fill the strainer with Ridlyme run pump long enough to get it in the hoses and let it sit for half hour or so to jeep crud out of water. I am in Salt water.

[Grizz]

Run one unit. If the evaporator ices up...
It's dirty.
Clean the condenser water filter/strainer.
Condenser water is the only thing common to both units.
Hope this helps

[Contract_Pendin]

Likely needs an acid flush of the ac lines.

[A_Lot_More_Misc]

So, thanks for the help from everyone, at this point, it looks like we need a new circulation pump, the existing one was overheating and kicking off. Hopefully the new one is installed early this week.