Cruisaire water pump

[eze2bme]

My 1979 43 DC has one circulating water pump for the two Cruisaire units. Yesterday the pump was working. Today when I turned on the AC I was only getting a trickle of water from the discharge thru hull. I have checked the following:
1. Strainer was clear
2. I dove under the boat and the pick up thruhull was clear
3. I checked the impeller on the pump and it was OK
4. I checked all fuses and they were OK

I'm assuming that the pump is original as the previous owner only used the boat 5 months a year (in fresh water) and was stored in a heated warehouse during the Winters. The wiring, hoses and screws look to be original. The pump is a Marine Development Corporation PMA 1000 115volt unit. It has a rigid plastic(?) impeller and apparently spins from magnetic contacts on the motor as the impeller has a large round magnet as a shaft --- if that makes sense. Both the inlet and discharge openings were clear.

Does anyone have any ideas or know if Marine Development Corp is still in business? I did a search on the Internet but nothing came up.

I'm considering disconnecting the hose from the pump and blowing out the intake line just incase something is blocking it. And if that is clear then trying the same with the supply hoses to the compressors ... blowing from the compressor back towards the pump. And if that is clear then connecting a hose to the discharge side of the compressor and blow back through it to check for a blockage.

But ... I'll wait to hear from you guys first ... I don't have a lot of room in the equipment compartment below the dinette ... and at 6-1 I don't fit very well!!

Thanks guys for any help or suggestions!

 

[Vic Clevenger]

My 1986 36SC has the same Cruiseair units from Marine Development Corporation. The pump on mine is original and was manufactured by March pumps. They are still in business. Try www.marchpump.com and you will likely find your pump. Or it may be marchpumps.com. Vic

 

[SKYCHENEY]

Try Depco Pump

 

[UNIQUE_NAME]

i have the same pump. what i found happening was pieces of the magnet breaking off and jamming the pump. after cleaning out the pieces worked like new. i guess its time for a new pump for me.

 

[Mike36c]

I had the same problem with a march pump a while back and after installing a new spare pump, still just a trickle. Try removing the hose from the strainer to the pump to see if there is ample feed flow. My case was about the same, dove the boat and it looked fine, cleared the strainer, checked the impeller, ran the pump. As a last resort I removed the strainer and plumbing down to just the thru hull, still a trickle, hmmmmm. It turned out there was a wad of small debris trapped in the pipe of the thru hull. Tried blasting it out with the ships fresh water, no luck. It took a coat hangar to clear the pipe! Reassembled everything and we were back in A/C.
Of course this happened early a.m. on the hook in mid summer five hours later, working next to a running generator, it was fixed. Good luck!

 

[Freestyle]

From my own cheap dimwitted experience, this is a great time to buy a $300 pump before the old one causes the purchase of a $2k or more air conditioner.

Those things really like a nice raw water flow.

Bruce

 

[captddis]

Before you buy a new pump check the voltage at the pump. Low voltage will make the pump run slow. There are a number of possible causes.

 

[jim rosenthal]

Probably the seawater path is clogged someplace. Generally the pumps either pump or they don't. March still makes all these pumps and they cost less direct from March if I remember right. There is no such thing as too much seawater flow, within reason. But I would see if the seawater path is obstructed someplace, because that is usually what goes wrong.

 

[bateau beau]

I had the same problem with my 1985 43' DC. Took out the strainer and cleaned it- still had a problem. Ran a coathanger through the thru hull- problem fixed!!!!

 

[OldHatt45]

ez2bme,

What the guys have said is spot on. When I bought my 45C it had a Model 500 pump. It ran OK.... Then I had a problem with one of my 25+ year old A/C units. Replaced the Unit and didn't replace he pump. About 6 weeks later, the old pump quit. Fortunately the A/C guy is a friend and Sold me a Model 750 pump for really DIRT Cheap. The 750 pump will suck the chrome off a trailer hitch (and you have a Model 1000). Point of this is, generally unless the magnet has come apart as UNIQUE_NAME said, you have a blockage. All the places mentioned are likely candidates. If you're in salt water, barneys love a nice steady water flow. Start at the Through Hull and go from there.

OldHatt45

 

[eze2bme]

OK ... I got lucky ... found a clog in the intake line right at the pump ... looked like chopped up pine needles ... weird! Guess that the needles passed through the Groco water strainer holes. I'm on fresh water and there has been a lot of stuff floating around the marina lately. I went ahead and blew out all the lines including using the shop vac and blowing out the line at the thru-hull to remove anything below the thru-hull strainer!

Thanks for all the great, helpful advise ... as usual ... this is an invaluable forum and knowledge base!!