A/C problem

S

susanandlance

Well-Known Member
Feb 10, 2011
2,865
Florida
Boat Info
2007 Sea Ray 36 Sedan Bridge
Engines
8.1 mercruisers
What is a P5 low code mean on salon a/c control? Low refrigerant?
 
It can be from a few reasons. It has happened to me several times. In my case, it was always from something being sucked up against the intake restricting the water flow from the ac pump. I have had plastic bags get sucked up against it and also in one marina, there were so many jelly fish that they restricted the flow. In those instances, I was able to clear the problem by starting the engines and move the gears at idle from forward to reverse back and forth. The props created enough force to blow the obstructions from the intake and restore water flow.
 
I had that PS alarm a couple times last season, and all I needed to do was was disconnect each A/C line down in the ER after the pump and blow each one out with dockside water pressure until the water exiting the hull was clear. It can also mean you have an extremely dirty strainer. I had my marina run barnacle buster through each unit this winter.

-Tom
 
TNT8808 said:
...disconnect each A/C line down in the ER after the pump and blow each one out with dockside water pressure....
-Tom
Click to expand...

Yep, usually means raw water is restricted somewhere...

Tom, weren't you concerned about pushing stuff into the system? It's def. easier your way...But, I typically undo the raw water lines at the units and back-flush into the bilge with the hoses being disconnected from the pump....Just thought it was safer that way....Though, if no issue, your way is easier for sure...
 
Boat Guy said:
Yep, usually means raw water is restricted somewhere...

Tom, weren't you concerned about pushing stuff into the system? It's def. easier your way...But, I typically undo the raw water lines at the units and back-flush into the bilge with the hoses being disconnected from the pump....Just thought it was safer that way....Though, if no issue, your way is easier for sure...
Click to expand...

Nope. That's how I was told to do it by an HVAC guy that works in our marina often so that's just how I've always done it. I've only had this boat for one full season, and the lines got clogged up several times during the season and of course it was always at the worst time. Before this past season I think I'd only had to blow out the lines maybe once a year at the most on previous boats. The PO didn't appear to be very concerned with maintenance type items.

Perhaps someone with more knowledge than myself, or the HVAC guy will chime in if I'm doing it incorrectly.

-Tom
 
The water flow is strong on mine coming out the hull port, I will check strainer, but fwd a/c is cooling fine and they both share the same water pump
 
IMG_20190605_095738736_HDR.jpg
 
Restricted cooling water flow will cause a high pressure shut down.....I think the code on the passport panel is "HI PS".

Lance's problem is low pressure shut down which is a usually caused by low refrigerant, very cool ambient sea water, or a restricted return air inlet.
 
susanandlance said:
The water flow is strong on mine coming out the hull port, I will check strainer, but fwd a/c is cooling fine and they both share the same water pump
Click to expand...

They both share the same pump and water should be coming out of both discharges regardless of which unit is running.
I had the Code in my forward unit. Strainer was clear.
I flushed with a garden hose from the manifold forward and it helped for a while but then I got the code again.
I removed the hose from the through hull and found some little barnacle debris type stuff. Cleaned that out and then flushed backward from that point back to the manifold and it did the trick.
 
The water is doing exactly that, as far as both exit ports, I'll check strainers next trip to boat, thanks to all of you fellas for the great info!!
 
JVM225 said:
They both share the same pump and water should be coming out of both discharges regardless of which unit is running.
I had the Code in my forward unit. Strainer was clear.
I flushed with a garden hose from the manifold forward and it helped for a while but then I got the code again.
I removed the hose from the through hull and found some little barnacle debris type stuff. Cleaned that out and then flushed backward from that point back to the manifold and it did the trick.
Click to expand...
Were you out of the water when you found debris in thru hull?
 
fwebster said:
Restricted cooling water flow will cause a high pressure shut down.....I think the code on the passport panel is "HI PS".

Lance's problem is low pressure shut down which is a usually caused by low refrigerant, very cool ambient sea water, or a restricted return air inlet.
Click to expand...
Thanks Frank
 
susanandlance said:
Were you out of the water when you found debris in thru hull?
Click to expand...

No.
I had to pull out a set of drawers in a forward closet to get to it.
Looked like the debris got hung up on the little lip of the fitting where the hose slips over it. Probably happened when I flushed forward.
 
I'm leaning to low refrig. like Frank said because it wasn't cooling to good two weeks ago and now it runs and shuts down but fwd unit is cooling fine
 
fwebster said:
Restricted cooling water flow will cause a high pressure shut down.....I think the code on the passport panel is "HI PS".

Lance's problem is low pressure shut down which is a usually caused by low refrigerant, very cool ambient sea water, or a restricted return air inlet.
Click to expand...

+1 here!
 
Me too, A/C guy is going to look at it this week, too hot down here, temps been 95-97 everyday for last two+ weeks!!
 
For the record mine comes on when the boat gets hauled out. The fix is to force water pressure in. Simply disconnect a hose aft of the pump and connect a high pressure water nozzle and verify water is coming out of the discharge hole(whatever it’s called). Essentially priming the system. This has worked for me.
 
Doing all the Salon windows in ceramic limo tint tomorrow as well, that will help some too
 
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