Domestic Cruiser Hi PS error

[Stickman]

There are years of threads on the source of this error.
I have 4 systems and 3 run flawlessly but the master stateroom unit shows this error. Seawater intake and pump not the apparent issue since three units can operate at the same time the 4th shows error.
Any ideas before calling tech? Have been through the online and printed manuals.

Have not tried a compressor flush yet as there are contradictions to owner suggestions and owners manual. The latter requires equipment purchases I'd need to make.

Thanks!

 

[GregBrannon]

Is it Dometic Cruisair?

 

[DavidM]

Compare the raw water outlet from the condenser on the bad A/C unit to the good ones immediately after it causes the high pressure error. Measure the temp of the tubing right at the end with a heat gun after it goes through the condenser. If it is significantly higher, say 3 or more degrees then you have low raw water flow which is causing the high pressure error.


The low flow is either caused by a plumbing problem or a fouled condenser. I wouldn't be concerned about a Barnacle Buster flushing of the condenser.


David

 

[Stickman]

yes it's a Dometic Cruise Air Emerald.

I'll try the heat gun diagnostic. Thanks for the assistance!

Sandy

 

[Star0210]

We just had this issue the other day with ours. We also have 4 units and it was only happening on one. We flushed the system and lots of brown yuck came out for quite a while. We left it flushing all day. Works great now. In fact, they are all working better. Nice and cold on the boat.

 

[DavidM]

Here is a little more info as to what you are looking for:

A normal A/C unit raises the raw water temp 5-10 degrees as it goes through the condenser. If an A/C unit is tripping the high pressure alarm that means that the freon is getting too hot either because the raw water flow is restricted or the condenser is fouled badly. Either way the raw water temperature will be higher than normal as a result.

This test is really to see if the alarm is good, ie there really is high pressure or if the sensor is bad. If there really is high pressure, the only way that can happen is if the raw water flow is restricted or the condenser is fouled.

Maybe a simple eyeball of the raw water outlet, comparing it to the others will tell you if it is restricted. It can be restricted either by a plumbing problem or a fouling problem. If the flow is lower than the others then focus on fixing that problem. You don't really have to do the temperature comparison then.

One way to determine if it is plumbing or not is to remove the inlet hose and put it in a bucket and time the filling time. Do this immediately after you turn it on because with no flow it will quickly hit high pressure. Compare that to the other A/C. If it is significantly lower then it is a plumbing problem and not a fouled condenser.

But more than likely the sensor is working right and it is a fouled condenser. Post again and we can discuss how to flush with Barnacle Buster.

David

 

[Comodave]

I flushed my A/Cs with Barnacle Buster not because I was having a problem but just as PM. Can’t say if it made any difference because I wasn’t having any problems. But I also flushed my main engines and one dropped 5 degrees and the other dropped 10 degrees. I had the ends off the heat exchanger last week to retrieve broken anodes and they looked fine.

 

[Stickman]

Hmm, this internet photo URL appears in the reply box, but maybe not to the reader.

This is my condensor. The seawater enters the top double loop and there are 90 degree attached metal tubes, which I presume go to the condenser coil, nd carry flow away from the coil back to the larger outflow tube.. It would seem a small fraction of the cooling water flowing through the top tubes flow 90 deg down the small caliber tubes to the coil.

Best to check seawater flow at the 90 degree pipe attachment; vs the plastic hose to metal pipe connection on the larger top seawater tubes?

The temp of the larger tube is only 3 deg higher than inflow (88-90 deg F) , but the little tube I believe is from the condenser is 106 deg.