Fresh water pump

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drb1025

Guru
Joined
Oct 20, 2012
Messages
703
Location
USA
Vessel Name
Fiddler
Vessel Make
DeFever 46
I’ve gone through three or four 12v Shurflo/Pentair variable speed pumps over the last 7 years. Not very good. I’m looking for a better system. I have a 46 ft DeFever with shower, sinks in head and galley, fresh water flush for head, flush for Watermaker, and a spigots in the cockpit and bow. 4-7 gallons per hour is sufficient. What are some reliable brands for variable pressure pumps and would you advise installing an expansion tank too? Thanks
 
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I’ve gone through three or four 12v Shurflo/Pentair variable speed pumps over the last 7 years. Not very good. I’m looking for a better system. I have a 46 ft DeFever with shower, sinks in head and galley, fresh water flush for head, flush for Watermaker, and a spigots in the cockpit and bow. 4-7 gallons per hour is sufficient. What are some reliable brands for variable pressure pumps and would you advise installing an expansion tank too? Thanks


What are you doing to abuse these pumps so badly?


I had a variable on the previous boat for years and it worked great.. after I got rid of our expansion tank. My impression was the variable pumps have a hard time with expansion tanks.


On our current boat we have a Groco Paragon Sr pump that I think will outlast me.
HOLLYWOOD
 
What are you doing to abuse these pumps so badly?


I had a variable on the previous boat for years and it worked great.. after I got rid of our expansion tank. My impression was the variable pumps have a hard time with expansion tanks.


On our current boat we have a Groco Paragon Sr pump that I think will outlast me.
HOLLYWOOD



I too have wondered if I’m abusing them somehow. I use 3/4” hose from the tank to the pump and from the pump to the whole house water filter. It then feeds into 5/8” copper piping throughout the boat. Could it be the filter or the sizing of the hose?
 
Maybe not abusing them. I would check the line voltage when it is running. The voltage at the electrical connections to the pump should not drop when the motor kicks on. Maybe you need a heavier gauge wire.
 
The variable speed pump is a waste of electric.

Longer lasting is the simple pump with pressure switch and the largest accumulator you can fit .

KISS
 
I had a bunch of Shurflo failures too. Turns out the pressure switch mechanism is total ****. I bypassed it and used an external pressure switch like you'd see on your sump in your house. Added a 2 gallon accumulator into the system as well. Now the thing works like a champ (for a couple years) and we have tons of pressure.



Buy one of the Square D pressure switches from SupplyHouse. DO NOT get one with the 'low-pressure cutoff'. Just get the normal $12 one - super awesome.
 
You have a DeFever which means you have lots of room in your engine room. I have a DeFever 44. I danced your dance (several 12V pumps) before, based on a suggestion on this forum, settling on a Grundfos MQ3-35 110VAC pump. It is large but not much more of a space eater than a system that employs an accumulator tank. The Grundfos has its own internal expansion tank. This pump is a boat miracle. It supplies constant, more-than-adequate volume and pressure with absolutely no change in either. Plumb it, fill the internal tank, turn it on. Done.

You will, however, need a 110VAC outlet to which to plug it in. I ran a new supply line from a spare breaker to a dedicated outlet. I used 10 gauge wire rather than acceptable 12 gauge wire to minimize resistance but that was probably overkill. If you already have an accumulator tank, you could get the same result with a shallow well pump which would be a much less expensive solution. The Grundfos goes for around $625 but you will never have to replace it.
 
Count me in on the separate pump, accumulator and adjustable pressure switch crowd. Forget the VSD.

Our DC pump was an old fashioned GalleyMaid diaphragm model which was totally refurbishable. The PO had installed it incorrectly when setting up a dual pump configuration (the other being an AC shallow well pump, which was great), so I traded it in as a core towards a refurb by Raz Marine in Ft. Lauderdale. It worked beautifully for the following almost seven years of full time year-around live aboard use, the majority of it an anchor or on moorings. Built like the proverbial tank. Water Pumps | Raz Marine | Fort Lauderdale Florida

I got great service from a Shurflo raw water washdown pump too, so wouldn't hesitate to try a unit from them, but for a couple hundred more, hard to beat the Raz units for heavy duty use.

Or, as always, I encourage you to call the very honest, knowledgeable and helpful folks at Depco Pump in Clearwater and discuss your situation. Fair prices too, especially considering the service. Depco Pump Company
 
I have had good luck with Jabsco 31620, has an integral accumulator, it's on or its off, had them on two boats, no issues.
 
Thanks for the replies. I plan to increase the wire size to 12, from 14, and try a Marco gear driven variable 12v pump. I am also removing the whole house filter and straightening the water line flow by removing two elbows. I’ll put a filter under the galley sink for drinking water. I don’t want to go to an AC pump as we rarely run the generator and I’d rather not rely on an inverter to power it. I’ll keep the warranty replaced Shurflo as a spare backup.
 
Mine works perfectly, going on about six years. Sometimes I hear it cycle at night when no water is running but I think I have a leak in the pressure side. Going down below today to search it out.

pete
 
You have a DeFever which means you have lots of room in your engine room. I have a DeFever 44. I danced your dance (several 12V pumps) before, based on a suggestion on this forum, settling on a Grundfos MQ3-35 110VAC pump. It is large but not much more of a space eater than a system that employs an accumulator tank. The Grundfos has its own internal expansion tank. This pump is a boat miracle. It supplies constant, more-than-adequate volume and pressure with absolutely no change in either. Plumb it, fill the internal tank, turn it on. Done.

You will, however, need a 110VAC outlet to which to plug it in. I ran a new supply line from a spare breaker to a dedicated outlet. I used 10 gauge wire rather than acceptable 12 gauge wire to minimize resistance but that was probably overkill. If you already have an accumulator tank, you could get the same result with a shallow well pump which would be a much less expensive solution. The Grundfos goes for around $625 but you will never have to replace it.

This is a great solution if you have AC power. Most would consider it overkill but it beats 12v issues. A dedicated breaker is needed because of startup amps. Also install the right pressure switch to avoid straining your hoses. Also, I read that your generator should produce clean sinusoidal power for the pump to work to specs.
I had well water in FL. The Grundfos pumps were the high standard as they were more durable and corrosion resistant. But because they were expensive many used Goulds, a good pump but when exposed to weather, became impossible to service from corroded bolts.
 
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First off, the point of failure was never mentioned. So all the solutions offered are random guesses as to what the failure was. More diagnostics is required. Is it a motor failure or is it a pump failure? What is amp requirements for the pump and does dose your wire gauge provided that adequately?
 
First off, the point of failure was never mentioned. So all the solutions offered are random guesses as to what the failure was. More diagnostics is required. Is it a motor failure or is it a pump failure? What is amp requirements for the pump and does dose your wire gauge provided that adequately?

Good point and the OP just mentioned removing a whole house filter and elbows. That may help too. With the whole house, try removing the element first. It's possible that the element is too fine and a coarser element is in order. Some boaters use a portable filter that connects to dock hose. It filters all water going into tank filler and can also filter city pressure when hooked to dock water fitting. It never affects the pump output side.
 
First off, the point of failure was never mentioned. So all the solutions offered are random guesses as to what the failure was. More diagnostics is required. Is it a motor failure or is it a pump failure? What is amp requirements for the pump and does dose your wire gauge provided that adequately?



After a poster suggested looking into the wire size, I found a short length of 16 gauge wire that I used on a previous pump installation. This was completely inadequate for the larger capacity pump that recently failed. Thus, I am now using an appropriately sized wire. That was a contributor to the failure, perhaps the primary cause. The elbow restrictions did not help, but the pump should have handled them. In any event, I decided I don’t need a whole house filter, rather an under sink filter will be fine. I likely don’t even need that as I sanitize the system annually and turn it over frequently.
 
Good chance that's the culprit! At least for the most recent failure.
 
When looking at DC pumps for many the difference between the cabin service pump and a bait well or deck wash pump is totally the size of the motor.

The longer motor will eat more juice , but not as much as the tankless pumps that have builtin bypasses.

A 12v deck wash pump, at least a 2 gal accumulator and a house pressure switch does not compare with a Headhunter one of the other superb units , but they all eventually do need service , and the base line is about a grand cheaper , and can be found anywhere.
 
We have a Marco pump and really like it. I initially wanted a Headhunter but didn't have the space without a lot of modifications, haven't regretted the decision to go with Marco. Let us know how it turns out for you.
 
After some thought and reading more posts, the 120v Grundfos is overkill for your boat and needs. An expansion/accumulator tank allows you good pressure and quantity without the pump kicking on every time you open the faucet. It saves the pump and less noise. If you think the pressure switch is low quality, it should be easy to use an external switch.As pointed out, you should find the external cause. If that small wire wasn't the whole issue. I don't see multiple posts about pumps constantly dying.
 
After some thought and reading more posts, the 120v Grundfos is overkill for your boat and needs. An expansion/accumulator tank allows you good pressure and quantity without the pump kicking on every time you open the faucet. It saves the pump and less noise. If you think the pressure switch is low quality, it should be easy to use an external switch.As pointed out, you should find the external cause. If that small wire wasn't the whole issue. I don't see multiple posts about pumps constantly dying.

I agree. I have given up on buying $200 "marine" pumps.

I switched to a high-rated $70 RV pump from Amazon and a 1 gal accumulator tank from Lowes 2 years ago. Bought backup pump and made electrical quick-change connections just in case.

First one still working flawlessly - used 24/7 living aboard.
 
I installed the Marco pump today, increased the wiring to 12 gauge, and installed a 20 amp breaker per the installation guide. It is very quiet and did not pulse in my limited testing. I think it is going to work out well. I hope to not ever need the Shurflo spare. Thanks for the suggestions in the thread.
 
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