Air conditioning

[winedown]

We have a 396 Carver MY with 3 AC units...had the AC winterized by the marina as we are not very mechanically inclined...The aft AC seems to be working but the AC in the salon comes on but water flow is not great...We get an error message HPF and then water flow stops..Could this be due to strainer needing cleaning...I think there is only one sea cock for all 3 units ..not sure if they do something when they winterize that we need to undo??

[pepmyster]

Check the strainer. Are you getting water coming out everywhere. You might have to put a hose on the exit hole for the water of the ac system and push water back in. Could just need a prime.

[winedown]

Thank you...I think the strainer is just in front of the generator but hard to get at ??..Is the strainer & sea cock for the AC unit located about 18 " to the right (starboard side) of the genny...As I said, we only get the HPF message on the centre unit so I thought the water coming in through the thru hull was ok & that it must be a problem relating just to the one unit??...Water seems to be coming out but not a strong flow as it probably should be...After 5 to 10 minutes the flow stops and we get the error message...

[tomschauer]

You have one pump for all three units. If just the one unit is a problem maybe you had some critters nesting in that outlet over the winter?

[Tireless]

I have a Carver 44 CMY which is essentially the same boat. You are correct when you say that there is one sea cock in the boat that is located within inches of the strainer and the water pump. All of your units are on the same water line. The water flows in the seacock, through the strainer and into the pump. The water gets pumped through a manifold which sends water to each of your three units. In my boat the salon and state room units exhaust their water out the rear of the boat and the unit in the "V" berth exhaust out the front on the port bow. You are also correct to assume that the error code you are seeing is a water flow issue.

The water flow issue is low in one, it would be low exhausting from all your units, not just one. It possible that the salon unit, because it is the largest in the boat, may be registering the error code for that reason. If it is low only from one unit I would suggest there may be a blockage or a kink in the hose, but that is doubtful.

The sea cocks, the strainer and the water pump are in the same area and if it's like my boat it's in front of your starboard engine near centre line. The first thing to do is close the sea cocks and remove the strainer top and check for debris in the filter. If that is clean it would be important to make sure that you pump is working to capacity. When my pump failed, it registered the same as your situation and the pump was extremely warm to the touch. It is possible you require a new pump.

I would also check the filter on the actual unit. If this is dirty it will cause the unit to freeze up. The filter is a thin mesh that is on the side of the coils. Remove this clean and dry it and put it back on.

Try some of these things and advise the forum how you have made out. Hard for us to tell without being there.

If the problem persists I recommend you call Bob at Northland in Keswick, 1-905-478-2244. He is very knowledgeable and sells and repairs everything in relation to your air units. You can report what's going on and will will give you a good idea on what is going on. I am not sure where you are, but he may be local to where you are.

There are also good marine mechanics that can look after the problem as well.

What I have advised you may help you understand what may be going on there.

Good luck.

Greg

[bud37]

I had a rather large spider block ours.....shop vac sucked it and the debris from it out......might be just as simple as that like Greg suggested, cause the water has another path to exit it can't blow the clog out.

[winedown]

Thank you for all the suggestions...As you have probably guessed, we are not real knowledgeable when it comes to working on our boat & that is why we enlist our marina to do most of the work...That being said, sometimes it is like pulling teeth getting them to come & assess the situation especially now during covid...Also, if this is a simple issue It would be great if we could solve it ourselves rather than incur a huge service charge...I have checked & cleaned the filter on the unit..Bit dusty but not bad...We appreciate your suggestions & will give it another try when we return to the marina on Friday...Will let you know how we make out..Thx again...

[Viper]

Technically HPF refers to a refrigeration system High Pressure Fault or Freon. In cooling mode it's likely restricted/reduced raw water flow but in the heat mode, it could be due to restricted air flow.

They may not have primed the entire system properly. Usually once you get the pump primed and pumping, it should pump through all the units at the proper rate but that unit may not have purged properly. There are several ways to prime the system but perhaps if that unit's discharge port is easy to get at, close the seacock, take a garden hose and run water into that unit's discharge outlet from outside the hull. It's good to have two people here.... when it's filled, turn off the water, have someone at the seacock, turn the unit on, and when the pump kicks in, open the seacock.

Something else to try is block off the other outlets and check to see if the faulty unit's discharge increases. If it doesn't, you have a restriction in that unit's raw water circuit.

Do you know if the vessel was originally a salt water boat? If it was, you may have a problem with the condenser lines. Even if it wasn't originally in salt water, this could happen due to some environmental conditions. Usually a system flush with a product like Barnacle Buster will clear growth but it won't remedy a problem with the coil itself.

It could also be a faulty pressure switch or a bad board. There is a procedure to check those. Let's hope neither are the problem.

[winedown]

Thank you all for the suggestions...In the end, we had an AC guy come in & the system needed priming...All is good now...Thx again..

[Tireless]

Glad it was something simple. Always good to ask first.

Greg