A/C cruisair high pressure shut off switch

[Olde Hatt]

Cruisair AC unit 220 v shuts off with High Pressure code but the pressure is not high. Can't find where to get replacement part.

 

[Captain Ralph]

We know the pressure is not high,, how??
Readings??


What was the code?

 

[zigzag930]

Don't forget to check water flow.... restricted (clogged strainer, kinked hose, etc) #1 reason for high head pressure.

 

[carolinacoast]

or time for system to be flushed. one of ours was doing that before the annual cleaning.

 

[Pascal]

Any part can fail but I don’t think I ever had a high press switch replaced on any of my boats or the boats I ve ran over the years.

Are you sure pressure isnt high? How is the water flow and when is the last time the system was descaled ?

 

[rwaldrop13]

Any part can fail but I don’t think I ever had a high press switch replaced on any of my boats or the boats I ve ran over the years.

Are you sure pressure isnt high? How is the water flow and when is the last time the system was descaled ?

Crusair isn't the only one having issues with this - My 2month old MarinAire is doing the same thing and I have sparkling clean strainers.

 

[Pascal]

There is a lot more to it than having a clean strainer. Many times I ve had debris in the lines, especially in manifolds, blocking water flow to one unit only. Or at the thru hull... plastic bags stuck and randomly reducing flow

 

[zigzag930]

I ran acid through all my AC coils and checked all my hoses, etc. Had great flow from all units, but one was still shutting down on HP. Condenser coil was getting very hot to the touch when running only a minute or two.

Turned out it was a blockage on the above waterline discharge port. Never thought to even consider that could be blocked. Anyway, clearing it out fixed my issues.

 

[Pascal]

I ran acid through all my AC coils and checked all my hoses, etc. Had great flow from all units, but one was still shutting down on HP. Condenser coil was getting very hot to the touch when running only a minute or two.

Turned out it was a blockage on the above waterline discharge port. Never thought to even consider that could be blocked. Anyway, clearing it out fixed my issues.

The sea water pumps don’t put out much pressure so things can get stuck in the lines all the way to discharge.

In SoFl we ve had issues with small shells growing in the lines then dying and coming loose when hauling out for bottom paint. When you restart they all get stuck there.

 

[Passages]

I just went through this with my Cruisaire unit. The issue was hard shell critters taking up residence in the 12' hose between the sea strainer and the 220v rw pump.

The simple cure was to completely clean out the strainer, shop vac the strainer and the hose from the seacock. Then pour in a gallon of white vinegar and half cup of muriatic acid. Let the acid do its work for about 30 minutes. Then seal up the strainer, open seacock and bump the rw pump until the foamy vinegar begins to appear at the discharge. Stop and let it work for another 20 minutes. Bump it again just to move a bit more acid. Repeat. Then turn on AC and be amazed how much cooler the coils operate.

 

[Olde Hatt]

Thank you for wonderful suggestions. I should have been more specific in my first post. I know from following that questions here get serious analysis.

I have cleaned the strainers twice, acid washed the water lines of the unit (yes, a lot of crud in the system) and had my A/C guy put the gauges on twice. The acid wash did bring pressures down a bit and did make the unit more efficient. However the the unit is not consistent. It will shut off as soon as I turn on cool and the next time it will run for hours before the HI/PS starts flashing. We left the gauges on for enough time to have a beer and thing ran perfectly, and later that evening it shut down as soon as I turned it on. On the third try, it stayed on for several hours.

My A/C guy and I cannot think of what else the issue could be other than a defective shut off switch. I am wide open to any further suggestions.

Any idea where I might get a HI/PS shut off switch?

Jim
Olde Hatt

 

[Captain Ralph]

Any idea where I might get a HI/PS shut off switch?

From your A C guy?

 

[Olde Hatt]

My wife is the manager of two Inns that are part of a large group that owns several Inns. The A/C company that takes care of those Inns is now working with me on renovating a house. Their maintenance foreman has been helping me with this. The long running of the unit with gauges was an after hours call that he made to see if we could figure out the issue.

 

[Captain Ralph]

If you are positive that it is the switch and you have observed water flowing when the unit errors out, then bypass the switch. It is a normal closed switch.
This will further prove a switch or controller board issue if the error comes back.

Take a picture of the switch and copy the numbers down then post them.

I have a box of these switches that have been removed from condemned stations, not a clue what switch is high or low pressure switches. I'll match your number up to what I have. If I have it, it's yours.

 

[Olde Hatt]

Thank you, will be able to get that done this week I think.

 

[Entonces]

Just had to flush my whole system again (I flush it 2 times minimum a year). Replaced RW Motor & Pump w/ new thinking I dry ran it. After kicking my ass for 2 days doing all this to Cool the the wife off, units still shut off due to HP (insert multiple explicit words!). Had little H2o before & after all the work. Diver found a large oyster shell as I suspected something still restricting flow from through hull to strainer while I was enroute to airport. Told wifey to turn on AC and wahla! Still shut off due to HP! A buddy is suppose to go check it out as I suspect still more shell in the line but the jury's still out as wifey seems content waiting for me to get home in another week & half! Well at least I have that spare RW pump I always wanted as sure old one pulled is still working. Not a big fan of the magnetic drive/ non self priming pumps but they're half the price as the Dometic/oberdorfs. Yeah you can say the price of the 2 cost as much as the Dometic/Oberdorf but, I already went down that road. South Carolina sure does get hot this time of year!!!

 

[Pascal]

The March magnetic drive pumps are excellent and do not suffer from impeller erosion like the dometic oberdorfer which are non self priming anyway

I once had a march impeller fail, replacing the impeller was a 10 minute job as I didn’t have to even pull the hoses. Just pull the cover. And they can never leak.

Depending on how you flush sometimes shells get displaced around. Then when you start the pump they jam again usually in the manifold. Sometimes you have to take the manifold and hoses apart to do a complete job

 

[rustybucket]

Not sure that it makes any difference but I try to flush in reverse flow of what the unit is seeing. I've had some chunky stuff come out before that def would not have made it through the normal flow direction.

Weirdest thing that ever came out was a 1'+ section of small thin poly tubing. No clue how it got past the strainer, pump and into the unit, but somehow it did (or maybe it was inside a hose when installed).