Fresh Water Pump Problem

[OPUS]

About 18 months ago I replaced my dead Shurflo freshwater pump with the recommended factory upgrade (Shurflo Aqua King II Supreme). The pump has worked fine since installation. About 2 weeks ago it begin to not shut off, on an intermittent basis, after flushing the head or opening galley/head faucets. The problem occurs about 1 in every 5 uses of the freshwater system and is not limited to one specific water outlet. The pump will shut off after adding water to the head or turning on a faucet for 2-3 seconds. The problem is not specific to one water fixture and can be stopped by using a different water fixture.



This problem is not similar to a situation that occurred this summer when we left the swim platform freshwater faucet shower head in the closed position but did not turn off the water at the fixture after swimming. In that case the pump ran continuously when water starting trickling out of the faucet head. Once we located the problem and turned off the fixture the pump stopped. I assume a leak in our freshwater system would behave in a similar fashion.



This problem does not seem like a leak as the pump will shutoff. I have searched for water in my bilges and can find nothing that would indicate a leak. Any help on resolving this issue would be greatly appreciated.

 

[O C Diver]

Did you mount the strainer before the pump?

While I'm not familiar with that specific pump, it sounds like a pump problem. If the pump runs with all outlets closed, and there are no leaks, either the pressure switch isn't turning off the pump every time or there is some valve leak by in the pump. The valve leak by could be something on the valve face or a bad valve that doesn't always seal right. Do you have a pressure gauge in the system? A pressure gauge will help you diagnose a problem like this. If the pressure doesn't come up to the shutoff point, I would look at the pump valves. If the pressure goes above what you expect, I would be looking at the pressure switch.

Ted

 

[Russell Clifton]

Is there a pressure tank in the system? If so check the pressure in the tank.

 

[DDW]

If it doesn't shut off, that would be a pretty big leak and you'd have found it. And since it is intermittent, it must either be a bad pressure switch, or bad or clogged valves in the head. The head can be taken apart to look for debris in the one way valves. To check the pressure switch you'd need a pressure gage. Or, next time it does it, rap the pressure switch with a screwdriver handle and see if that stops it. The head can be rebuilt, and the switch can be replaced.

 

[OPUS]

So no pressure gauge or pressure tank is present in the system. There is a filter mounted on the inflow side of the pump. We occasionally get some black gunk that finds its way to the galley faucet so perhaps thats part of the problem. I'm winterizing the system this week so I should have an opportunity to check fittings before running the pink thru the fresh water systems. With all of the on/off at fixtures during winterization process I should have plenty of chances to try the screw driver wrap approach on the pressure valve. Will report back after the weekend.

 

[janice142]

I have had that problem on occasion. Inevitably it is a loose hose clamp somewhere in the system. Before blaming the pump, a quick tightening of the clamps might be worth your time.

As a side note, I check every hose clamp on Seaweed as the seasons change. There is ALWAYS something that needs attention, be it a replacement or simply a couple of turns wit the ratchet.

Good luck.

 

[Wxx3]

Welcome to my Shurflow world.
It's the pressure switch.

My switch failed completely this summer. I replaced the switch, but then noticed behavior similar to your experience.
With my switch there are instructions to calibrate the switch and the bypass.
I have not done that yet. It's on my list to do.

If it was a air leak, the pump would be more consistent and take forever to shut off eventually not shutting off at all.

 

[OPUS]

I'm pretty sure it's not a leaking hose clamp. I check/tighten every clamp (I can see) as part of my spring startup routine. My experience with this type of pump is that it will run continuously if it senses any flow/pressure drop on the outlet side of the pump. Just priced a rebuild kit which looks a lot more attractive then a new pump. Will see how it acts this weekend and will probably pull it and do a rebuild while on the hard this winter if it continues to act up.

 

[DDW]

I've had pumps misbehave similar to this and disassembled the head to discover debris in the one way valves. Cleaning it out solved the problem. In that case it was cedar needles, which would neatly go right through the Groco strainer. Anything that holds one of the one way valves (there are usually several in the pump head) open will allow pressure to leak back and cause the pump to stay on or cycle. Extra flow - like opening another faucet - can move the debris and allow the valve to seal for another cycle. A bad pressure switch can show the same symptoms. Since you should have both a rebuild kit and an extra pressure switch in on-board spares, the money isn't wasted - but I'd take it apart and see if there is something obvious in the head.

 

[drb1025]

I have had problems with my Shurflo pump cycling at low pressure or not shutting off. Here is how I fixed both of those problems:
Shurflo 4048 pump
Turn the center pressure adjustment at end of pump (5/64 Allen wrench) 1/4 turn clockwise one step at a time. Get to where the pump continues to run, no cycling, when the faucet is at very low flow. If you turn the center screw a couple of 1/4 turns and the pump continues to run when faucet is turned off then back the adjustment screw off 1/8 of a turn. You can get to where you have no cycling at low flow, but make sure the pump stops running when the faucet is turned off.

 

[tedted]

We had a situation where our Shurflow ran dry for a considerable period of time. I ended up having to replace it as it no longer operated reliably. I have since gone to using pumps for agricultural sprayers. They are essentially the same and the cost is considerably less.

 

[bayview]

first check that there are no obstructions in the inlet from the tank. If it is plugged the pump will keep running.

 

[Shrew]

Is this a variable speed pump? I replaced my pressure pump with a Shurflo variable speed pump. According to the marketing fluff, this model negated the need for a pressure pump.

I find that there is an issue with the pressure switch. It will sometimes not turn off and run endlessly. I end up needing to turn off the pressure pump breaker, wait 5 seconds then turn it back on. This, in itself, tells me the issue is not a leak on the pressure side of the system.

I'm replacing the pump with a standard pump and an expansion tank during this off-season.

 

[Lepke]

There will always be problems with the switch. It's contacts were designed for Ac and much less amp flow. You'll find the same numbered switch in microwaves, refrigerators and so on. Usually controlling lights or as a safety in microwave doors.
I'm sure Surflo and others that use a similar (or the same) switch are aware of the problem. I bought a new pump that didn't work right from the start and they gave me a new switch. Now when I use this design pump made by anyone, I bypass the built in switch and use an outside switch rated for the amp flow.

 

[Bacchus]

Is this a variable speed pump? I replaced my pressure pump with a Shurflo variable speed pump. According to the marketing fluff, this model negated the need for a pressure pump.

I find that there is an issue with the pressure switch. It will sometimes not turn off and run endlessly. I end up needing to turn off the pressure pump breaker, wait 5 seconds then turn it back on. This, in itself, tells me the issue is not a leak on the pressure side of the system.

I'm replacing the pump with a standard pump and an expansion tank during this off-season.

Agree
Some of the variable speed variety have had problems w the pressure sw and to make matters worse replacement switches no longer available (for some models) search the Jabsco site for your model # to be sure.
Someone poster the transistor # and how to replace it. I found the transistors online and tried the fix but couldn't get it to work constantly

 

[OPUS]

So we completed winterization of our freshwater systems this weekend. The pump performed perfectly during the multiple cycling needed to run the water out of all of the fresh water fixtures (2 staterooms with heads and showers) and then pumping anti freeze back through the cold and hot water lines. It did not fail to shut off once during the entire process. I plan on checking the valves in the spring for debri and have ordered the rebuild kit should it be needed during spring startup. Thanks to all for your helpful problem solving suggestions

 

[dieck]

I consider water sytems with just a pump that has an internal pressure switch very unreliable. Additionally the pump keeps turning off and on whenever water is used, is subject to unnecessary wear and in the end is unreliable. You really want a systen that sstable, reliable and easy to maintain and trouble shoot. In this case you need to have a pressure tank with a pressure guage and ist own pressure swtich thats generally much more reliable than the internal pressure swtches in the pumps. In this case you also need to set the pressure switch on the tank so that if shuts off before the pressure swtich in the pump would switch off. For safety I have added a timer that will shut off the pump if it runs continuously for more that about 30 seconds. My water system has run without failure for more that 8 years by now.

 

[clyde]

well, yrs ago, i replaced my normal jabsco fresh water pump, with the smaller washdown model, installed a 20/40 square D well pressure switch in the water line [on at 20Lbs, off at 40 Lbs] they cost abt $18 at our local ace hardware! the square D switchs usually last 10/12 yrs! i always keep a spare switch/pump on our boat...also have a 4 gallon pressure tank i found at home depoe, with the bladder, keep it at 18 Lbs [2 Lbs under the turn on pressure] has worked great for many yrs!...clyde