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Post by rlazar on Jun 8, 2020 9:02:13 GMT -5
Having a problem with our new 2020 38XO AC/Heating losing its prime, I think.
Here is the history:
Took delivery 2 weeks ago, AC and Heat barely worked. No codes just didn't' really cool or heat well. Have to run for hours before moving a few degrees. Turns out the AC pump was bad. Dealer replaced the pump and all was good but that didn't last. AC/heat worked all night, took the boat out the next day, came back and then kept getting HPF and no water was flowing. The strainer was clear. Dealer fixed but had to purge the lines/re-prime. The AC then worked well all week while the boat was at the slip.
Dealer had to recalibrate my autopilot so someone took the boat out and did that. One hour later my wife went into the boat and all the AC units said HPF and was not pumping water again. No matter what I tried, I could not get it to pump water.
Next day a tech came out. He loosened the strainer a bit, saw water was flowing then we turned the AC on and it was working again. I took the boat out that afternoon, came back to the slip and it was not working again. Called the tech and he said turn on the gen for 2 mins, then turn off. Then try the AC. That fixed the prime and the AC was working once again.
So here is the pattern. 3 times the AC was working we took the boat out and every time we came back, we had to re-prime to get it to work.
The Gen and AC share one pick up and massive strainer. Coming out of the strainer there the GEN feed. Y'ed off of the gen feed ( like a drop down) is a feed to the AC. Somehow I think when using the Joystick in reverse ( hard) and water is rushing under the boat its pulling/sucking water out of the pickup and creating a vacuum in the AC line. The tech says the gen feed is somehow fighting the AC feed and perhaps a check valve needs to be placed in the AC line.
When I get back to the boat next week I'll take a pick of the strainer and how the feed split off of it for the gen and AC.
The 38XO design has been out for a year and there are a number of them out there. If there were a design problem with the Gen/AC feeds I would think this would have been discovered by now. Otherwise, what else might be going on here?
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Post by gofast24 on Jun 8, 2020 10:02:27 GMT -5
Two weeks old you shouldn't have to put up with multi service calls. Talk to the sales manager where you bought/ordered the vessel.Agree, when out drive in reverse could cause aeration/air bubbles causing loss of prime on the sea water pump inlet but with Regal's good reputation they should have tested for that and remedied the problem before building your vessel.. I would let Regal Dealer find actual problem and fix it. If you not having much success with dealer give Regal customer service a call , have hull number available before calling. Good luck and le us know what resolved the problem..
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Post by rlazar on Jun 8, 2020 10:10:20 GMT -5
Two weeks old you shouldn't have to put up with multi service calls. Talk to the sales manager where you bought/ordered the vessel.Agree, when out drive in reverse could cause aeration/air bubbles causing loss of prime on the sea water pump inlet but with Regal's good reputation they should have tested for that and remedied the problem before building your vessel.. I would let Regal Dealer find actual problem and fix it. If you not having much success with dealer give Regal customer service a call , have hull number available before calling. Good luck and le us know what resolved the problem.. So I have to say the dealer has been super responsive. First they got approval (from Regal) to overnight a new pump so we would have heat/ac on the weekend since they knew we would be on the boat. 2nd, when we showed up Friday after 6pm and let them know ( view text) there was a AC problem again, they called and said they would call in a tech Sat morning. That tech is an expert and said they are now working with someone at Regal who deals with 38's in the field and looks for patterns/problems etc. I just posted the issue here to both see if one had any thoughts and also in case someone with a 38XO/GC is having a similar issue and finds this post. |
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Post by lg260ss on Jun 8, 2020 20:05:29 GMT -5
On page 112 of your owners manual there is a picture of the sea strainer.it looks like there is a check valve ( or some type of fitting)on the outlet side of the strainer. It’s hard to tell what it is because they put a label over it. Is that fitting on yours?
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Post by rlazar on Jun 8, 2020 20:55:05 GMT -5
On page 112 of your owners manual there is a picture of the sea strainer.it looks like there is a check valve ( or some type of fitting)on the outlet side of the strainer. It’s hard to tell what it is because they put a label over it. Is that fitting on yours? What tour are looking at is coming out of the strainer. There is the feed to the generator. There is a junction there that splits to a 2nd feed for the AC. The marine tech said there may or may not be a check valve inside that junction. He is checking with regal on that. This is where he feels the problem is but is waiting the hear back from regal engineering. |
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Post by lg260ss on Jun 8, 2020 21:08:03 GMT -5
This is the fitting I’m talking about. it’s off the side of the strainer where the feed goes to the AC and generator. It looks like it could be a check valve but it’s hard to tell.  |
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Post by omarf4 on Jun 8, 2020 23:09:37 GMT -5
The strainer is attached to your thru-hull, which is below the water line. It will fill up with water anyway, even if the reverse motion sucks water out for a few seconds, which would be surprising as the water pressure would be enough to keep water flowing through the thru-hull. Somehow the water is draining back down the thru-hull and the pump isn’t able to prime and lift water all the way to the AC. Head pressure in the hose I believe might be the issue and hence the check valve.
Where is the AC water pump installed on the 38? Is it next to the strainer or next to the AC in some forward cabin?
Either way, with it being such a new boat, I am sure regal/your tech will get to the bottom of it. Keep us posted.
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Post by gofast24 on Jun 9, 2020 10:17:44 GMT -5
Agree with Omar, thru hull on bottom of hull and pump hopefully still below the water line it should stay fully primed at least a foot or two above the pump inlet ! Not sure I like that one inlet thru one strainer connecting to both AC and gen set? On our 4160 Gen set and both AC units/pumps are separate inlets, sea cocks/strainers, AC pump(120 VAC) feeds both AC units, gen set has its own flexible impeller pump to cool it and doesn't need 120 VAC power to run gen set cooling system!. OK, if at sea anchored you need gen set to run AC unit, so when you start Gen set it provides AC power to sea water pump, then runs and with gen set 120 VAC power you can run AC unit as the gen is providing 120 VAC to the sea water pump and AC unit .You should expect dealr service fixing this before it gets too hot (like here in the ATL). Let us know what solution is !
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Post by omarf4 on Jun 9, 2020 12:43:05 GMT -5
I did some homework on this one as the OP had my brain going.... first, yes, I don't understand why the 38 has only 1 thru-hull/strainer for both those critical functions. Even my 33 has two, one for each function (AC / Gen Set).
Putting that aside, here is the current AC water flow based on whats in the diagrams for the 38XO:
Thru-hull (center of boat sump area) -> Strainer (Center bilge area) -> Y-valve (based on OP description) -> AC Pump (mounted on STBD side - from manual) -> Up to AC condenser (mounted forward) -> Back down to PORT side transom outlet (No flapper or Reverse check valve). On the 38, the AC outlet is on the transom facing AFT (not to the side). This is important as any fast reverse will create upward pressure through the transom outlet thru-hull, up the hose, into the AC cooling coil and back into the pump, which till drain the strainer and create an air trap. Not an issue 99% of the time, but any droop or curve in the entire chain of flow (hose) will create an air trap once the boat settles into its slip. Once that happens, the pump can't fight it and will lose prime.
My 2 cents...... will be following this one closely to see the outcome.....Let's see what the dealer tech finds.....
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Post by rlazar on Jun 9, 2020 13:10:36 GMT -5
I did some homework on this one as the OP had my brain going.... first, yes, I don't understand why the 38 has only 1 thru-hull/strainer for both those critical functions. Even my 33 has two, one for each function (AC / Gen Set). Putting that aside, here is the current AC water flow based on whats in the diagrams for the 38XO: Thru-hull (center of boat sump area) -> Strainer (Center bilge area) -> Y-valve (based on OP description) -> AC Pump (mounted on STBD side - from manual) -> Up to AC condenser (mounted forward) -> Back down to PORT side transom outlet (No flapper or Reverse check valve). On the 38, the AC outlet is on the transom facing AFT (not to the side). This is important as any fast reverse will create upward pressure through the transom outlet thru-hull, up the hose, into the AC cooling coil and back into the pump, which till drain the strainer and create an air trap. Not an issue 99% of the time, but any droop or curve in the entire chain of flow (hose) will create an air trap once the boat settles into its slip. Once that happens, the pump can't fight it and will lose prime. My 2 cents...... will be following this one closely to see the outcome.....Let's see what the dealer tech finds..... That’s for the research. Also to add there are 3 AC units all fed by one pump and one strainer that is shared with the gen. The ac outlets for the water are all at the aft transom. What’s interesting in the 38 are all water outlets are at the transom under the platform. So you don’t actually see any water pouring out from the AC , shower , sinks, bilge pumps etc. the only place where you see water output other than under the platform is the anchor locker drain. |
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Post by gofast24 on Jun 10, 2020 9:51:48 GMT -5
Three HVAC units on a 38? Great but now one more AC unit to service? OK, all outlets under the swim platform, really dont need to see all water flowing out of who knows what system, just need to keep eye/ear on gen set coolant temp and hope all the alarms/shutdowns are functioning!Believe gen set can shut down on high coolant temp/low oil temp but not the AC systems or propulsion engines.
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Post by rlazar on Jun 10, 2020 9:59:22 GMT -5
Three HVAC units on a 38? Great but now one more AC unit to service? OK, all outlets under the swim platform, really dont need to see all water flowing out of who knows what system, just need to keep eye/ear on gen set coolant temp and hope all the alarms/shutdowns are functioning!Believe gen set can shut down on high coolant temp/low oil temp but not the AC systems or propulsion engines. On my last boat I could just look and in 1 second see if the AC was pumping water. Same with Gen. This boat takes a bit more since in order to see water flowing, you have to look under the platform. I like the idea of the water output under the platform in terms of not seeing the boat "pee-ing" but on the flip side it takes a bit more effort to see whats flowing and whats not. 3 AC's.. nothing I can do about that. There is one for the lower forward/aft cabins and two for the cockpit ( port and strb side). I guess with all the glass it takes a lot to keep the cockpit cooled down. |
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Post by omarf4 on Jun 10, 2020 16:23:48 GMT -5
1 or 3, the water flow is in series...so one inlet and one outlet. If water is restricted or pump not able to clear the air trap, all 3 will shutdown. Having 3 is actually better for redundancy, it’s just all 3 are relying on a single point of failure. Something regal should look into and you should give them that feedback.
Let us know what the tech finds out as I still am convinced it’s an airlock due to hose having a drop or loop somewhere in the water flow path. The AC pump, being centrifugal, is unable to clear that airlock.......easy fix if that is confirmed in your case. Hoping for the best!
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Post by xixp on Jun 13, 2020 0:28:17 GMT -5
My previous boat was a 3760 and it had as well the Ac Output under the platform. I had as well the same issue with the Ac pump when using the Joystick. At the time i had been told that the some maneuvers created turbulence that “sucked the water out of the Ac Line. Since i had installed a flush port for the Ac and in that boat the Ac pump and strainer were under a lid in the salon it was easy to just open the flush valve to let the air escape and purge the line.
May be the current 38 has a similar hull design than the 3760 So the same problem is present.
But now i think that the problem was what Omar’s has pointed out because my Sc35 has both Ac out ports on the side and despite i keep my boat on a lift and use the joystick ive never had an issue with the Ac pump.
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Post by gofast24 on Jun 13, 2020 9:30:09 GMT -5
Thinking if what you indicated was also a previous problem that Regal would have noted it and corrected for future boats? Still interesting that a 38'has 3X HVAC units? Also, our 2X HVAC systems have one dedicated pump (120VAC) and dont believe it can be a rubber impeller style pump? Has to be a centrifugal pump as previously stated.. Our 20 year old boat has the original 120 VAC pump, feeding two HVAC unit s but gen has its own flexible rubber impeller pump. No problems with either? Have to admit having a boat is fun!Have had 9 different boats since 1979. Stay safe!
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