March pump replacement alternatives

For the third time in four years, I'm having to replace my March raw water cooling pump for my 16K BTU A/C. This is a really expensive pump that doesn't seem to last long. Maybe I've gotten 2 months of solid use out of each pump. The seals go, and starts leaking from the pump side to the motor and thats it.

The last time I bought one was in Coral Gables, FL from a "Distributor" that had nothing but a shabby little office with a desk and about 75 of these same pumps stacked in a corner. When I asked, "Hey, how come this pump is the only thing you have in stock", he just smiled and handed me the bill.

Anybody using anything else?

Your using the wrong pump, a magnetic drive pump is what you want for a A/C system, no seals to leak.
http://www.dometic.com/enus/America...ir-Conditioning/products/?productdataid=90290

Larry, For a 16000 BTU air conditioner you need a March LC-3CP-MD.
As Ron pointed out they are magnetic drive with no shaft seal to fail. They are liquid cooled. They usually last many years in service. It is available in either 115 or 230 volts.

"The March LC-3CP- MD magnetic drive pump is commonly used with marine air conditioners up to 24000 BTU. It is completely sealed and liquid cooled. It is sold by Marine Air as their P500/PML500. It is the Cruisair PM500. Inlet: 3/4” female Pipe Thread Outlet: ½” Male Pipe Thread Capacity 490 GPH at 3 foot head."

Give Depco pump in Clearwater a call, tell them what system you have and they will hook you up with the right pump. March are really good pumps given the right model in the right application. Depco also carries extensive parts for DIY and rebuilds almost all kinds of pumps. They sell direct to consumer as well as wholesale. Great company.

Depco Pump Company

Depco Pump Company Marine Catalog 111

Ron...that Dometic pump you suggested IS a March Pump...the same he is trying to get away from. I am going to give a write up about this company on this thread. I TRULY HATE THEM!!! in a bit I will tell ya how I really feel.

Stand by for rant::::
Bought a boat, replaced AC, used March 500 GPH already on boat. Lasted less than a year. +-$300 later new March Pump. 6 months later laid up boat for refit. 10 months after that refit done, AC reinstalled and moved back on. Month later pump goes down, flat spot on armateur. Hot, hot!! Found another pump (March) installed same. Now I have owned 3
March Pumps and have not gotten my moneys worth yet. Started trying to find March Pump Company. Never could find much information about the company, lots of retailers but the company??? I know why, they want to hide and for good reason. I finally found a factory rep. I explained my situtation and that I felt that I had not gotten fair service from the product. He agreed and felt that it would be no problem. I later got the feeling that he repped many companies and March was just one of. E mails flew for a few months. All I wanted was a spare, not a refund. I had plenty of impeller assemblies, just wanted a motor. He said March would not warranty being over a year old and he would get me one from his buddy in the shop. Monthly e mails for 8 months...no motor. Either he was lying or the company the represents would not listen and follow THEIR Rep's reccomendations. Either way I am done. I spoke to yard owners and AC techs, they sad that the pumps are pretty good but forget customer service.

Now I bought another boat, one month in the March Pump gave up. Purchased 6/22/2013, but there was an extended warranty from West, pump 3 days out of MFG warranty gave up, agan HOT. West replaced immedately and got this old fat man back in the hot bilge immedately. I bought an extended warranty for replaced pump. Now I have owned 5 March Pumps since 2009. When I run out of warranty replacements I will divest myself of any business with this unethical company. I have 1 defective March pump in possession, close friend has 2 more. They have NO serial numbers. I bet I can get even with this company. I do not usually do business this way but when you have to handle a tur4 you may get some shi+ on your hands. Work arounds..Buy extended warranty if possible, charge on American Express with extended warranty protection. Keep spare so your back will not be up against the wall because of the heat. Lastly, buy somebody elses pump.

I have 3, 16K BTU units all running from the same pump. It is an Oberdorfer pump, in the summer this pump runs 24/7 and it is 25 years old. Their claim is, that in 100 years they have a less than 1% failure rate. They are pricey, the one I have is 735 dollars but I believe well worth it. Just as the A/C pump, my fresh waterpump is a Groco Paragon Senior freshwater pump, again extremely pricy at over 3k but 25 ears old and works like a champ. Here is there website. www.oberdorferpumps.com

Most problems I have seen with the March mag pump are when it gets air loaded and continues to run. Pump head gets hot and plastic bushings melt. Might not be the fault of the pump.

Ski in NC said:

Most problems I have seen with the March mag pump are when it gets air loaded and continues to run. Pump head gets hot and plastic bushings melt. Might not be the fault of the pump.

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Bingo you are absolutely correct. I have a March AC pump on my old boat. It fed 2 16,000BTU MarineAir units. In the summer it would run 24/7 the only problems I had were related to making sure the pump was properly primed whenever the boat was hauled. Once she was in the water and the pump was burped allowing flow it worked like a champ. The pumps would be working 9 seasons now with -0- issues.
On my new to me Gulfstar I'm installing a 1.25 ton or 14,000BTU heat pump it requires no water but that's for another conversation. It will also allow me to work on the Gulfstar in comfort when I'm on land.
Bill

"Pump head gets hot and plastic bushings melt. Might not be the fault of the pump." I don't have one but, yes, it is. Plastic bushings? Chinese crap?

In a pinch you can always hook up the dock's fresh water supply in place of the pump. It'll work like a charm until the marina finds out what you are doing. In fact when the water temperature climbs into the 70 plus degree mark it will work better than using any pump that draws water from underneath the vessels hull.
Bill

... I have a March AC pump on my old boat. It fed 2 16,000BTU MarineAir units...

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Same here. One, Marsh AC-5CP-MD pump feeds our 2-16K units. It has worked great since we installed it in 2009 and I even ran it dry a few times. I bet Larry has the LC-3CP-MD. Still a centrifugal pump with a magnetic drive but a different head. Hard to compare the 2.

There was a time when March was having problem with their pumps. It was when the A/C companies had changed their systems to turn the raw water pump on and off with the compressor. March pumps didn't like all that on and off stuff. But March redesigned the pump to cool better as I recall and the problems stopped.

I can't say why you're going through pumps like that. Although it does sort of sound like there might be some issue other than the pumps themselves causing the failures. But I can say is I've been using March pumps forever in a lot of different boats and to provide cooling water for a number of different types of systems and never had them repeatedly fail like that.

And the shaft and washer the impeller ride on are made of ceramic not plastic.

As to the company itself, it's not to hard to find:
1819 Pickwick Avenue, Glenview IL 60026
Phone: 847 729 5300
Fax: 847 729 7062
sales@marchpump.com

It's a US company owned by members of the family that started it in the 50s.

Yes, the impeller rides on ceramics, but the ceramic rod sticks into recesses in the plastic housing. The rod gets hot and deforms the plastic housing. Rod now holds impeller off center and impeller rubs.

It's not cheap chinese crap, it's a water lubed pump and the bearing system seems to hold up as long as water is circulating. Well, it might be chinese...

My boat is prone to airloading the pump. Blame the stupid designer for that!! (me) I ruined one pump as it airloaded while sleeping. My bandaid fix is a switch that allows pump to run with ac off, so I can check for prime. Running offshore fast in rough stuff air loads it half the time. Need to put the right clamshell on the pickup (later).

Since I figured it out, pump has worked well for like 6yr.

My MarineAir units will shut down if the raw water supply feeding them isn't proper. At the same time it shuts the raw water March pump down. They will continue to cycle but if there isn't flow everything shuts down. I have no idea why the original poster is having so many problems I too would suggest the larger AC-5CP-MD pump also I'd suggest reviewing the raw water feed system before the pump something doesn't sound right with this installation. Is it possible you are drawing air into the pump? After it's primed and you are let's say for arguments sake tied to the dock it shouldn't lose prime if it does then investigate the raw water feed installation.
As far as hooking up a hose from the marinas fresh water system it's a good test but I would never suggest this as anything more than a test.
Bill

A clam shell might help. Is your water flow run all up hill with no dips in the hoses starting at the inlet? In most cases if you can get that right the pump will self bleed pretty easily.

Capt.Bill11 said:

A clam shell might help. Is your water flow run all up hill with no dips in the hoses starting at the inlet? In most cases if you can get that right the pump will self bleed pretty easily.

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That's the problem. I ran the hoses without much regard for air traps and to re-do it would be a major hassle. Live and learn.

I might put a tee right at pump discharge (below wl) and tap off a tiny bleed line and run to a nearby discharge through hull. But in the mean time, the switch works ok. The system is not idiot proof.

Had a cruiser pull that in Merritt Island. Nobody could take a shower, fill their tanks because of no pressure, no volume. After we keel hauled him he was forced to get the hell out of the marina.

If they piss off enough people as they have me they will not be a family owned or any other kind of business soon. I wonder if the inheritors understand the value of customer service. I bet the founders did. As I said, I am on my 5th March Pump. 2 different boats. The systems are installed properly, pump and strainers below the waterline. 3/4 in feed 1/2 in after the pump to the AC. No reason for pumps to run dry, water flows down hill.
Had March shown some concern, their rep followed up I would feel differently but their lack of concern is total disrespect and shows contempt for their customers. I am an angry, disappointed, disgruntled but good customer what with owning 5 of their pumps....I have done my part with my money and am entitled to have and broadcast the treatment received from these yahoos.

Mule, what is failing on the pumps? All the same? Have you done any autopsies?

Mule said:

Had a cruiser pull that in Merritt Island. Nobody could take a shower, fill their tanks because of no pressure, no volume. After we keel hauled him he was forced to get the hell out of the marina.

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Mule I 100% agree. It totally mucks up the legit use of the dock fresh water supply. As I said this should only be used for testing purposes or in a real pinch and very limited. Some people don't care about their slip neighbors. These types need to be shown the exit...

As far as the original poster I'd redo the AC water pump plumbing getting rid of potential air locks otherwise you should expect the same results, a failed AC fresh water pump.
I have often wondered if you could do a close system for the AC cooling water effectively giving yourself a source for hot water? Then again it would be too complicated and it would require having a dedicated fresh water tank for the AC units and a way to replenish the water used. The more I think about it the more I'm convinced that's a bad idea.
Bill

Mule said:

Ron...that Dometic pump you suggested IS a March Pump...the same he is trying to get away from. I am going to give a write up about this company on this thread. I TRULY HATE THEM!!! in a bit I will tell ya how I really feel.

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There were 2 pumps in the link one is the same as mine. It is a magnetic drive and there is no way that water can get into the motor unless the boat sinks. In 5 years the only problem I've had is the ceramic shaft that turns the impeller broke, I rebuilt it, all new parts for around $80.00. Mine runs 24/7 from mid June thru mid September, 1 pump for 2 units and at least 1 unit is always on, I'am reasonable certain it's the original pump from 1987. Maybe the build quality on pumps built now is not as good.

One pump went hot, would cut out then ac would shut down because of no circulation. I imagine the cooling loop of copper inside the epoxy molded base went bad, likely the same on number 2 where the pump would run then jam. Free up the shaft and it would run then 15 min later again. shaft surged. in all cases I disassembled to component level...as far as I could and there were no impeller issues. There are no air into the system leaks, all double clamped with good hose...on both boats. Yeah, I own 2...want a really great Mainship 34 1982/2013 for less than 1/2 what I have in.
The above was #1 and #2, number 3 is in Mainship and still working. Number 4 quit pumping, being on an enforceable warranty I looked at the impeller, all OK and headed to West. Number 5 is in New Boat and I am cool, wife is not as mean. I am waiting for the next shoe to drop. Seems to me $300. a year for raw water pumping for air conditioning is a bridge too far. I will be buying the $750. pump mentioned above when the rest of the Marches and warranties are gone. Hell it is only 110vac mermaid 16500 btu unit, has a big Gtocco strainer. I only ask that the things do their job.

...I too would suggest the larger AC-5CP-MD pump...

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Be careful going to a larger pump. This was discussed a year ago. Here are 2 posts where too large a pump (s) caused failures.

"So I started looking for a replacement. I noticed that Mermaid published min. and max flow rates for their units. I had not seen max flow rates on any other site, so I called Mermaid tech support and was given this answer - “too much water results in turbulence and if there is any grit in the water it’s like a little sand blaster. It takes a while but you end up with little holes.”

Next I called Aqua Air and got the exact same answer."

I went down into the engine room and looked at the pump name plate for the first time - 1000 gal per hour - double the recommended upper limit by both suppliers.
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"That's it. There doesn't have to be any grit, the high velocity will erode the tubing walls all by itself. If there is any contamination like a tiny barnacle sticking to the side of the tube it will create a cavitation bubble behind it that will fairly quickly bore a hole in the tubing wall and put seawater in the refrigerant that will instantly destroy the compressor."

Yes the pump has to be right sized to the system; bigger is not better.

March has an excellent reputation with many many users that recommend them after years of trouble free use.

That's one of the big benefits dealing with Depco, they know this subject inside and out and I can testify they really stand behind and support the products they sell. Their repair and refurbishment work is beautiful as well.

I'm away from the boat right now and I can't recall the model, but the A/C needed 280 GPH and the pump was more than that. Right now, it's leaking through the motor side where the power cord enters. As far as pump conditions, I don't know how much better it can get. I pulled off the top of the strainer (which was clean) and had to get the top back on quickly. Both thru-hull and strainer are deep below waterline, and the water is only pumped maybe 5 ft. maximum with no dip and maybe 2 ft. vertical to the A/C. I've never been underway with A/C on and have thru-hulls cleaned regularly. Stream out the exhaust side is consistently good, even now, but how long is a pump going to last when it's leaking out of the motor housing?

Maybe Parks (Hopcar) can get me a super deal on the Rolls Royce of pumps. Thanks for the great feedback guys. Mule....I feel your pain, unfortunately.

Well, my AC does fine and I am using the recommended 500 gallon per hour pump, on both units. I can see how sand blasting could be an issue for the AC but right now I am fuming over the lack of concern from a company that was considered the benchmark after $1500 worth of pumps have passed through my ownership. I will be dealing with deco for ANYTHING but a March.

Ski in NC said:

That's the problem. I ran the hoses without much regard for air traps and to re-do it would be a major hassle. Live and learn.

I might put a tee right at pump discharge (below wl) and tap off a tiny bleed line and run to a nearby discharge through hull. But in the mean time, the switch works ok. The system is not idiot proof.

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Bummer. Don't you hate when there is no one to blame but yourself.

A bleed line is what I was going to suggest. I think it's well worth a try.

The $750 Oberdorfer mentioned is a great pump, there is one, (104M) feeding the 5 systems on my Hatt; lasted about 30 years until killed by an OS problem (operator stupidity); however I don't think they make anything that replaces the March appropriately, and the magnetic drive system of the March is in some ways superior, though replacing seals and impeller is easy (Depco sells a kit). I also had an Oberdorfer DC oil change pump, both units built like the proverbial tank and priced accordingly. They are also the OEM maker of the larger Cruiseair pumps. and are about 200 bucks cheaper when bought from Depco with the Oberdorfer label.

Mule said:

Had March shown some concern, their rep followed up I would feel differently but their lack of concern is total disrespect and shows contempt for their customers. I am an angry, disappointed, disgruntled but good customer what with owning 5 of their pumps....I have done my part with my money and am entitled to have and broadcast the treatment received from these yahoos.

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Based on your posts it's unclear, to me at least, as to whether you ever contacted March directly? Did you? And if so what did they say?