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AC Circulation Pump Longevity?

Posted: August 16th, 2023, 6:27 pm
by Midnightsun
How long do these last? Will the brushes eventually fail or bearings go bad?

In my case a single 1000 gph unit does all 3 AC units so if it were to go we have no more AC. We do let it run 24/7 all season long and the boat is now 16 years old. No clue how the previous owner used the AC though.

I am going to order an extra AC circulation pump and keep it on board just in case the original decides to give up which is usually when one needs it most. Maybe even get a spare potable water pump while I'm at it because those are rather important also. Not like you can get these at the corner store either. I did have one go out on me on a previous boat and ended up putting in an aquarium pump as a temp fix until the new one was delivered. The aquarium pump worked very well by the way.

Re: AC Circulation Pump Longevity?

Posted: August 16th, 2023, 9:12 pm
by pepmyster
How long do they last? Damm good question. My only ick is are the new ones as good as the originals? Those pumps always astonish me with their longevity. I believe that if is a constant runner, they have less likely to die.

Re: AC Circulation Pump Longevity?

Posted: August 17th, 2023, 9:28 am
by km1125
The pump could last forever if taken care of properly. What will kill one is an overheat. What type do you have?

On most, there are no brushes, it's an induction motor with a magnetic drive to the impeller, so the motor is sealed from any water. There are some "heat tubes" that are used for cooling the motor, so if they aren't pumping water then they can overheat.

If the strainer gets clogged or the impeller gets full of debris, or you get an air pocket trapped or there's some growth on the thru-hull then the water flow can be blocked or stopped. This will cause the pump to overheat. Some have a resetting thermal breaker inside so when they cool off they'll start again and others have a thermal fuse that will just trip. Either way if it gets that hot the coils inside could be compromised.

So, keep them clean and keep them flowing and you likely won't have an issue.

Re: AC Circulation Pump Longevity?

Posted: August 17th, 2023, 10:24 am
by Midnightsun
Pump is a PMA 1000 by March. Now called a AC-5C-MD. https://wateryachtsolutions.com/dometic ... 225500065/

Also found that Koolair makes an exact replacement. https://www.crookandcrook.com/products/ ... 5a4c&_ss=r

Re: AC Circulation Pump Longevity?

Posted: August 29th, 2023, 6:09 pm
by Hugo
I have same pump as you 3 years older, original and runs all the time. Bought a spare years ago thinking just like you are and it’s been sitting in the box for years. I once called them and they told me could run a very long time!