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Chiller troubleshooting

Discussion in 'HVAC' started by Pascal, Jul 29, 2021.

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  1. Pascal

    Pascal Senior Member

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    With a chiller system air temp readings at the air handler isn’t that important as it is completely dependent on the chilled water temp.

    to cool the boat properly, it needs to be below 50 degrees and during the day all three chillers need to be on to get there.

    One critical factor is sea water temperatures. When i run pump nr 1 with the new impeller above but eroded body, coil temps are 5 degrees higher than on pump nr 2, condition unknown.

    Not a big difference in amps though , at most 1 amp per chiller, but it seems like the breaker holds longer

    At this point, i need to get the pumps rebuilt or replaced.
  2. Capt J

    Capt J Senior Member

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    REPLACE, and quite frankly I'd put the pump on it's own breaker thats properly sized for it.
  3. Pascal

    Pascal Senior Member

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    Each pump and chiller has its own breaker inside the cruisair cabinet. For some reason Cruisair set up the whole thing to be fed by only two lines from the main panel.

    made a few calls today, complete Scot pumps as well as head assemblies are back ordered. No eta. Going to try the spare I have on the 84. Same model
  4. Pascal

    Pascal Senior Member

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    Update.

    i replaced one of the two sea water pumps with a rebuilt one 3 days ago and so far so good. The breaker hasn’t tripped and I have been able to get the loop at a constant 47.5 to 49 degrees since. Makes a big difference inside the boat. Obviously:)

    i m having another spare rebuilt as well and will swap it for the second pump, which I suspect also has a lot of erosion.

    EED6C7D3-EC38-4C84-8B56-736B462120A1.jpeg
    TahoeJohn likes this.
  5. Capt J

    Capt J Senior Member

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    I don't rebuild seawater pumps, I replace them. The amount of money spent to rebuild them simply isn't worth the savings, and then the motor goes......
  6. mapism

    mapism Senior Member

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    I prefer to neither rebuild them nor replace them, it's rather a matter of chosing the best stuff.
    I've seen 30+ years old boats with the original Gianneschi seawater circulation pumps, never refurbished and still working flawlessly.
  7. Pascal

    Pascal Senior Member

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    Breaker has been holding fine till last night after returning to dock. Quickly realized that the middle coil on chiller nr 2 was much hotter than the others. Each chiller has three coils.

    back flushing the whole chiller didn’t help has the water took the easy path they the other coil. Disconnected that coil and sure enough... this came out.

    In this case the coil was so hot that just touching them revealed the issue but other wise an IR Gun is a great tool. A few weeks ago I wrote the temps on the coils to have a baseline. Very useful.

    Attached Files:

  8. Capt J

    Capt J Senior Member

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    OK, but bigger question, how on earth did that make it through the sea strainer?
  9. dennismc

    dennismc Senior Member

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    There was a time a few yrs ago when the general feeling among lots of Florida cruisers was to eliminate the sea strainer and just use the exterior strainer on the thru hull, I doubt that was Pascal's situation but strange finding indeed
  10. Pascal

    Pascal Senior Member

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    Strainer basket had a small crack. It’s a plastic groco. I m ordering a new one and in the meantime used a zip tie to close the seam.

    next haulout I am putting an external strainer on the air con. I ve had them on my own boat for 3 years now they work great. I m in the next slip and no issue with stuff coming on and no strainer to clean.
  11. mapism

    mapism Senior Member

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    External? Wazzat?
  12. Pascal

    Pascal Senior Member

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    They re also called South Bay strainers. Instead of having wide slots, they have a bronze mesh which is removable and replaceable in the water (diver). The mesh prevents stuff from being ingested. Works really well.
  13. mapism

    mapism Senior Member

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    I had to google for it, but now I see what you mean.
    Just curious, since you said that they are working well on your boat: did you ever run airco also under way?
    By the look of them, I'd expect the pump to struggle a bit more to suck water when it's flowing along the mesh surface, compared to when the boat is static.
  14. Pascal

    Pascal Senior Member

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    Air runs 24/7 inches under way. I installed the same type for the mains when I repowered. No issues.
  15. mapism

    mapism Senior Member

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    Interesting, thanks.
    Luckily, in my usual cruising grounds I have zero problems of this type, marina included.
    But I'll keep that in mind for if and when anyone will ask me a suggestion on this matter.
  16. Capt J

    Capt J Senior Member

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    They're much much larger than the thru-hull. I have had an issue with the holes getting plugged up IF neglected for a very long time.
  17. Pascal

    Pascal Senior Member

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    I ve instructed my diver to brush them every month.
  18. rtrafford

    rtrafford Senior Member

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    Try to time your diver with a shut down and avoid pulling up all of the crap he shakes loose. I'm not a fan of your direction, bit to each his own. I oversized my strainer to 2" strainer for a 1.5" thru hull. Much bigger basket, and several clean replacements on board for regular swaps. I like cleaning inside of the boat versus underneath.

    But nice find on the backflush! Obviously your breakers are doing their job...mine is holding nicely, too, post my clean up.
  19. Pascal

    Pascal Senior Member

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    The crap the diver shakes loose is so small (fitting thru the mesh) that it s no worries.

    I ve been using these for years on various boats and it s been great.

    another issue with slots is that plastic bags get stuck in them and don’t come off unless you go remove them... usually on a Sunday morning at 7am. Used to happen at least twice a year. With the mesh as soon as the pump shuts down, the plastic bags floats away.
  20. rtrafford

    rtrafford Senior Member

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    Agreed, in that my mains and genny's all function with sea strainers but fed from similar screen wedge coverings.

    I installed a bronze T in my HVAC hose just prior to my sea strainer, reduced the T down to 3/4 and installed a pencil zinc bonded to the strainer. I have a fitting that I install into that pencil port whereby I can introduce Red Line for cleaning, water if somehow an air pocket is blocking the prime, but I can also backflush the through hull in the event that I pull a bag or similar. I'm not opposed to your direction here. Just haven't had enough issue to warrant another hull attachment yet.