31TE Air Conditioning keeps tripping

[SJR]

Had a question on a recent issue this past weekend.... A/C unit cools for a few minutes then trips and blows warm (the amps go to zero and the refrigeration units turns off ) Ive read some troubleshooting on this and is points to a possible water flow problem or water pump failure.

was wondering if anyone had any advise on how to check for this and/ or pinpoint what may be wrong. Thanks, any info would be greatly appreciated, system cooled great last weekend.


SJR

[RobS]

Could be a voltage drop on the shower power supply, have you ruled that out? Does the a/c panel give you a fault code?

[DougSea]

Checking a water flow problem is easy, just check the discharge. When your AC is on you should have a solid stream of water flowing from the overboard outlet. Looks like a bilge pump discharge.

If there's not a strong flow you may have a pump or filter problem (have you checked your AC sea strainer?)

You say the unit trips. So I'm asuming the 120 panel breaker does NOT trip, and the blower stays on. Is that right? If so, and you have good water flow, I'd get a technician to look at it.

Good luck!

[SJR]

thanks guys, I checked the the A/C unit and it seems to be in working order. It kicks on and works, then shuts off and just blows with no refrigeration. I cleaned the strainer basket , that seems to be fine, however there is no water flowing overboard. Both the strainer glass and pump seem to be on however reminds me of a pump thats running but not primed. I guess that leaves the water pump? seems no water is making it to the a/c system?

the 120 does not trip and the blower stays on.

[RobS]

Sounds like she is sucking air and needs to be primed or the pump is shot.

[kathylsails]

We had that problem with KP Duty a couple of years ago. Even though the water pump was running, the through hull valve was not opening. Replacing the valve solved the problem.

[Marcy K]

We had the same problem last summer. It turned out that the strainer had an air leak and wouldn't/couldn't hold a prime. After taking the strainer apart and cleaning it, we primed it and sealed the threaded ends. The heater/AC has worked perfectly since. Hope its that easy!

Marcy K
A 34 Paumanok 1986
Falmouth, MA

[Nancy]

We have to prime our unit every spring. And if we haul mid-season and leave the through-hull open, we have to prime again. Symptoms are exactly as you describe.
Take off the first hose coming out of the pump and turn on the AC unit. If water comes out of the hose, the pump is fine.
Turn off the AC unit.
Put the hose back on.
Turn on the AC unit. If water comes out the through-hull fitting, you're finished. If not, turn off the AC unit.
Take off the inlet hose at the AC unit and turn on the AC unit. Water should come out the hose. Turn off the unit. Put the hose back on. (If water doesn't come out of the hose, you need more help than I can give you. )
Turn on the AC unit. If water comes out the through-hull fitting, you're finished. If not, turn off the AC unit.
Take off the outlet hose at the AC unit and turn on the AC unit. If water comes out the hose, turn off the unit. Put the hose back on.
Turn on the AC unit. If water comes out the through-hull fitting, you're finished. If it doesn't, the problem is over my head.

There might be more than one way to do this - I don't know - I'm not really an HVAC girl. This is what works for me.

Good luck!

[N4QC]

The easiest way for me to reinitiate the prime for the AC system on my vessel is to take a water hose with a nozzle and back flush the cooling system. With the AC off, direct the nozzle into the AC discharge port on the hull. Turn water on for a minute or so. Turn off water - turn on AC. If after two or three failed attempts I would suspect the pump. This of course assumes that the previous suggestions about the clean filter, the filter housing, valves and air sources into the system have been addressed .

In checking out the pump you may be able to verify that the impeller is free to spin by removing the outlet hose and outlet connector from the pump. This would give you access to the impeller whereby you should be able to spin it with a finger. Make sure that the power to the pump is turned off first.

Access to the pump is another matter…

Happy trouble shooting,

[DougSea]

Hey SJR - as you can see from the above many suspect a priming issue. Just in case you're not aware, A/C pumps are NOT self priming. They SHOULD be installed below the waterline, but aren't always. There are some great suggestions above for checking/establishing a prime.

Based on your reply above, lack of water flow is certainly your issue. With luck it's a lack of prime or an air leak, at worst you need to replace your pump. Not a terrible job (depending on the pump location!) and a quick fix.

[JackK]

What they said ... priming the a/c pump.

Mine is a proverbial pain in the neck. It is not below the waterline and every year I have to fight with it during commissioning. The method that has worked the best so far is - (a) shut the a/c seacock, (b) pull the hose from the seacock by loosening the hose clamps, (d) turn on a freshwater hose to a moderate flow, (d) while forcing water into the a/c hose have an assistant turn on the a/c. and (e) once the flow is established (wait for a couple of minutes), quickly replace the hose and open the seacock. Make sure you tighten up the hose clamps when finished.

I have had to repeat the above process several times depending on how fast I can get the hose back on the seacock. I keep meaning to relocate the pump but since it has never lost prime once I get it going for the season, it remains low on the to-do list.

Jack

[DougSea]

Jack - On Sonny III I had the same challenge. Pump was just at the waterline and would not self prime. I put a tee into the raw water wash-down feed just behind the bulkhead where it fed the hose bib. Took a feed off of the tee, ran that to a valve and then a tee in the A/C raw water line, between the pump and the thru hull. To prime the system I just turned on the wash-down pump, opened the valve, and voila! Cost was 2 tees, a valve, and some hose. Convenience was priceless!

Makes winterizing a breeze as well.

[RobS]

Suprised to see how many struggle with the priming of the pump and have never added a freshwater flush or a priming connection. Doug's priming connection is a great solution but the freshwater connection (flush) I did in T-R is even better. Remember the a/c is subjected to the same ill effects of seawater as the cooling loop on the engine.

You can prime the a/c but you can also flush it with freshwater when not in use and it makes winterizing a snap - close the seacock, open the freshwater connection valve and wait for pink to come out of the side of the boat.

With the water heater right there it was simple to "T" into the cold water supply.

Never touch a hose clamp again..

[SJR]

Awesome info, thanks to all. It is my first season with Teagan II, and was on the fence as to call a tech, hopefully I can get it primed myself. Learned allot already. The pump is directly below the Helm, once I get a quick break from work Im all over it. I love the the Tee and fresh water flush, that will be on the off season list.

[Nancy]

hopefully I can get it primed myself.

Hey, if I can do it, anyone can.

Our pump is below the waterline, but the AC unit is uphill from there. In theory, it should prime itself, but it doesn't. Also, the shooting water in the through-hull trick doesn't work for me.