Haul out and raw water pump failure

[Driftwoods]

This summer I had the water pump">raw water pump for my AC replaced. Worked great. A couple of weeks ago, I had to get my boat hauled out for a little work and now the pump is burned out. Because of my travel schedule, the contractor I hired (based on a number of recommendations) is the one that took over the boat and went from slip to yard and back to slip. All I had done was replace the prop, cutlass bearing and new zincs while it was out. Because a prior contractor had turned on the AC this summer without opening the thruhull, burning out the pump, we had specifically asked the new contractor to pay attention to the AC and it's condition so we could avoid a repeat.

The AC was turned on when I got back to the boat but no water pumping through it. It's got power, thruhulls are open and clear, etc. The contractor tells me it's not uncommon for a haul out to leave the pump unprimed, which I don't really know about since the pump itself sits below the waterline. I'm not sure how it could remain unprimed.

The contractor tells me there is absolutely nothing he could have done that would lead to this pump burning out. But here's the thing, he was very careless. He left the boat unlocked and with the keys in the ignition. He also backed the boat into the slip but left the spring line so long that the stern got pushed under the dock and rubbed. Fortunately, my neighbor in the slip is a liveaboard and all around decent guy and took care of things before it could get stolen or any real damage done.

Consequently, I'm thinking the contractor may have been in a huge rush, got careless, and done something he shouldn't or not done something he should have.

Any opinions out there?

[colemj]

The circulating pumps on most AC systems are not self-priming, even when below the waterline. The problem is the air lock on the head side keeps them from pumping. Simply cracking the outlet and putting the hose back on while water is pumping will overcome the airlock. Or attack from the inlet side by putting a waterhose on the inlet to fill the entire system.

I don't understand how the AC could be on without water flow. The temperature would rise quickly and the thermoprotection would shut it down within seconds. If this is not happening, you have electrical issues with it.

Turning on the AC without water flow should not have burned out a pump either, because the pump should be wired to shut off with a compressor error. Also, the circulating pumps commonly used are run-dry pumps with magnetically coupled impellers.

Mark

[Driftwoods]

The AC has a, for lack of a better term, a breaker on it that shuts off the compressor before it can overheat. The fan will stay on though.

My thinking is, the contractor was is such a hurry that he ran off the boat without checking anything and the reason the pump burned out was he was careless. Am I over the line on that?

[JPA Cate]

Yes, you're a bit over the top, because you have not yet primed the pump to be sure it is actually damaged. Plus, I bet you have to eat it anyway, just like the scuffing on the stern. Really and truly, if you want work done just the way you want it, you have to be there, watching the whole time, unless you really know the workman. I can think of two people I've met that I'd be comfortable working on our boat without us, depending on the job, in 27 yrs. cruising.

[Sailmonkey]

Over the top I think. Lesson learned, when you have work done to your boat, turn off all systems that someone may not even realize are on.

[colemj]

Is your pump actually dead? As in not making any sound or using current at all? These pumps can run dry for quite a long time and not have a problem. They lose prime because the water drains out through the thruhull when the boat is pulled and the air in the head line locks them up. If it is running but not circulating water, try priming it like I mentioned above. These pumps will never prime themselves because they are like the fresh water pump in an engine and not like the raw water pump.

Mark

[Driftwoods]

Originally Posted by Sailmonkey

Over the top I think. Lesson learned, when you have work done to your boat, turn off all systems that someone may not even realize are on.

We did very clearly tell them this would be on and that it should be addressed before taking the boat but for whatever reason they didn't do it. There should have been no surprises or unknown systems to contend with.

But yeah, lesson learned. In this case I was unable to meet at the boat for the haul out and could not reschedule for quite a few weeks and was out on business for a week after the work was completed leaving the pump to run dry for a entire week (I have confirmed it was burned out). It's certainly my fault to trust that a job would get done properly without my presence. Never again.

The contractor has agreed to split the cost of replacing the pump - he's actually a pretty stand up guy. I'm happy with that resolution to this. I appreciate all the feedback and advice!