First I have to ask if the pump is actually pumping water thru the unit & overboard ???

How much water is it pumping overboard…. Full stream, or just a trickle ???

If not full stream then you still have a flow problem…Try blowing out the intake thru-hull & flush some water with the garden hose thru the system…You may have a sand blockage down the line somewhere…

There is no manual reset per say…There is a factory programming reset but this does not seem to be needed at this point, and if you do it, you will loose any programming changes that the installer of the system may have calibrated for your installation…Factory presets are just that and are by no means are intended to be whats best for your system installation…They are just an original baseline programming set…

Steve~

Hi Rick…Thanks for posting~

First off guys…There is NO manual reset on Marine Air equipment…Mermaid has one on the High Pressure switch (and that may be what you guys have heard about) but they are the only manufacturer I have run across that does…

All other marine a/c units I have serviced or know of have a Automatic Reset high pressure switch….

The positives to an auto reset hi/ps switch are you don't have to access the unit to reset/press it…But most systems now have digital control to do the shutdown and fault display for you…Manual resets are good for manual control units that are left running unattended…If you come back and nothing but the fan is running then you know the reset is the first thing to check…With digital control, that is not necessary because it will tell you what went wrong by flashing a fault…Either way HHH flashing, or tripped reset…Water flow must still be checked & fixed before running again.

Two things normally cause High Pressure and are thoroughly covered all over this site & forum…Low water flow & Scaled up Condensers acting as a insulating blanket preventing proper heat transfer…If you have full water flow…Your unit may need flushing with acid to remove that scale restoring it's heat transfer to the water.

The high pressure switch is there to protect the unit (and you) from high side operating pressures of over 425 psi (R-22 units) Normal operating high side pressure on a clean unit, with rated water flow thru it, should not exceed 200-275 psi depending on water temp entering…So you see…There is quite a bit of room to allow for diminished flow, or a dirty condenser before the switch shuts it down.

What can happen with a auto reset switch is (and this is likely your case Rick) The switch has cycled so many times that it has worn itself out and will no longer reset…The digital control sees the "open" switch, and even though you cleared the fault…As soon as it is powered up to run mode again it thinks the compressor should not run because the switch will not reset…

The only fix is to replace the switch…Unfortunately with Marine Air of your vintage it's a soldered in switch…A screw on switch can be installed (leaving the old soldered in switch, but just just moving it's wires to the new) on the high side gauge port with a flare tee (so that you still have a gauge port) and you can test your existing switch by cutting it's wires & twisting them together (going back to the control) But only do this as a test DO NOT RUN MORE THAN A FEW SECONDS to confirm the compressor will run with no fault display….We know you had a fault causing this in the first place…Running a unit without high pressure protection is dangerous to you, and will also kill the unit…

As far as a manual for fault codes…I just looked, and all that Marine Air is offering is the manual for the AH Passport II which is for Chilled Water A/C and won't have your settings or fault codes…

You might try contacting Micro Air http://www.microair.net/index……&id=46 who built the control/s and see what they have to offer… Be sure your control is the Passport II (which has no penguin on it's face)

Steve~ 

Hi Steve,
I just saw your reply post and you hit the switch on the head. It only happened once before according to my understanding of the program perameters for HP on passport II. Setting U6 was set at #3 which states it requires a manual reset of the unit. #1 and #2 reset every 90 Seconds after the HHH display.
Thanks for the info on the switch. I was tempted to run it over night but in my checks I also broke the tab on the comp overheat switch and figure I had to many safety's removed. I'll let it rest and do an pressure check tomorrow and run some muriatic acid through the coils unless you can recommend something safer.

If I need to open it up I think I'll switch to r22a Evir0safe. I put it in a 5k unit I have and it never worked so well before with r22. It also has a low operating pressure.
What do you think about putting a "T" connection with a pressure guage at the HP switch tube?

Thanks for the help and great advice. You were right on the mark and the additional info eased my furrowed brow
Rick

Capt Rick said:

Hi Steve,
I just saw your reply post and you hit the switch on the head. It only happened once before according to my understanding of the program perameters for HP on passport II. Setting U6 was set at #3 which states it requires a manual reset of the unit. #1 and #2 reset every 90 Seconds after the HHH display...Just for everyone's info…I would stay with the #3 setting, and by manual reset they mean that after 3 attempts to restart/run the system, It shuts down & you must then reset the control by cycling the power…not a button  on the switch…This is best if running unattended. 
Thanks for the info on the switch. I was tempted to run it over night but in my checks I also broke the tab on the comp overheat switch and figure I had to many safety's removed. I'll let it rest and do an pressure check tomorrow and run some muriatic acid through the coils unless you can recommend something safer.

If I need to open it up I think I'll switch to r22a Evir0safe. I put it in a 5k unit I have and it never worked so well before with r22. It also has a low operating pressure.…Stick with the R22…Regardless of claims, Replacement refrigerants are blends, and never better than what the system was designed for…Lower operating pressure on the low side can cause you icing problems & R-22 will likely be available for at least the life of that unit.
What do you think about putting a "T" connection with a pressure gauge at the HP switch tube?...It's an ok idea, but a switch is more important since you don't watch a gauge all the time, and if you get too much weight on that connection, the tubing will tend to fracture (copper "work hardens") from the compressor vibrations while running…Then you loose all freon.

Thanks for the help and great advice. You were right on the mark and the additional info eased my furrowed brow…Glad to help !
Rick

Steve~

To all…
I had a local Cruisair dealer come to my boat and fix my A/C. I believe he said the High pressure switch was stuck open. Instead of taking out the old, which he said can be laborsom, he just by-passed it with another part that he had. Sorry this is pretty vague, but I can't remember all the pieces he was taking about…and it was 2 months ago.
Regardless, he fixed it and it has worked great since.