Freshwater pump not turning off

[mikeling]

I have a 2007 Chaparral Signature cruiser. The original freshwater pump has been having low water pressure. It now does not turn off automatically; I have to manually turn of the pressure switch.
Since this pump is 10 years old, would it be better to just replace it with a new one than trouble shoot it?
If replacement is the route, do I have to get the exact same OEM pump? Can I upgrade the pump to a higher one?
It is easy to replace the pump?

Appreciate your thoughts.

[sailormed]

Use whatever pump you want. It is only water you are pumping. Check the piping installation, you want to avoid air bubbels accumulating in the pump. As the pump switches off based on pressure, an air bubble et the point of the impeller means no pressure build up and no switch off. Good Luck!

[ranger58sb]

Originally Posted by mikeling

I have a 2007 Chaparral Signature cruiser. The original freshwater pump has been having low water pressure. It now does not turn off automatically; I have to manually turn of the pressure switch.
Since this pump is 10 years old, would it be better to just replace it with a new one than trouble shoot it?
If replacement is the route, do I have to get the exact same OEM pump? Can I upgrade the pump to a higher one?
It is easy to replace the pump?

Start by asking advice from the pump manufacturer. (If it's Jabsco, for example, the XYLEM/Jabsco folks have a help line. As do other makers. Have the pump model number handy.) They may be able to diagnose symptoms and describe ways forward. One of those might be replacing the pressure switch; another might be replacing the whole pump.

(Might be you've gotten your money's worth from the original...)

If replacement is the best option (freshwater pumps don't usually cost an arm or a leg), start shopping on the model you have, then you can branch out to look at other options if appropriate. Compare GPM and PSI in what you have to GPM and PSI in new pumps that are available. You CAN -- maybe -- increase GPM/PSI if your piping will stand it (and if it's all PEX, usually it can stand higher pressures than what might have been originally installed).

Note that some pumps are made to work best with an accumulator, some without. Keep that in mind while shopping, and learn which you have in advance. You CAN change types, if necessary... just be aware.

But another reason for starting your shopping with the model you have... is that the mounting could be a one-for-one swap; out with the old, in with the new, done deal.

But if you decide to change pumps for whatever reason, one possibility is that your new target pump may also mount using the same systems (screw holes, whatever)... especially if it's made by the same manufacturer as your original, and perhaps in the same model series that they make...

And then again, you can usually just remount whatever pump you buy, adapting the hard mount and the plumbing attachments as necessary.

-Chris

[Catnut]

Just replaced my Flojet water pump for similar reasons. The overhaul kit for the old pump was 50% of the cost of a new one. So I thought it made more sense to buy new.
Tony

[John_Trusty]

Continuous running could be a couple of issues - bad pressure sensor (usually integrated with the pump) or downstream leak. You've addressed the solution of a bad pump, but have you ruled out the downstream plumbing leak? How dry is your bilge, and do you have fresh water leaking into it from a leaky piece of flexible tubing or faucet? You mention that it runs "continuously" - really continuously like a tap is open fully, or on-and-off like the tap is open partially? If you suspect a leak, spend some time searching around the cabinets and tubing runs to see that you do not have leaks.

Also, an often overlooked issue for "low pressure" is freshwater inlet strainers or filters that clog up. Do you have one near your pump?

[a64pilot]

If you don’t have a clog, since it has been having low pressure lately and due to its age, I’m betting on a bad valve or valves as in leaking. Overhaul it or replace it.

[Privilege]

It depends on what pump you have, but usually it's the rubber diaphragm that wears and causes problems, the motor is usually O.K.

Many water pumps have a service kit. They are easy to replace. Once the rubber diaphragm starts to go, it has trouble sucking up water and more importantly, it cant pump enough water to generate sufficient pressure to turn itself off. If the motor is running fine and there is no obstruction on your inlet side, that is likely the problem.

[SVRocinante]

Originally Posted by mikeling

...
Since this pump is 10 years old, would it be better to just replace it with a new one than trouble shoot it?

I just replaced my freshwater pump as well (also 10yrs old) after trying to repair the old one (call me frugal) - I'd suggest that it's probably not worth the trouble...

Originally Posted by mikeling

...If replacement is the route, do I have to get the exact same OEM pump? Can I upgrade the pump to a higher one? It is easy to replace the pump?

As ranger42c mentioned, you will most likely make the installation easier by going with the same/similar model pump. That said, after 10 years, mine was no longer available, having been replaced by a newer model and I had to drill new mounting holes anyway.

All in all, it is not a difficult job; shut of the water to the pump, unclamp a couple of hoses, remove the old pump (typically 4 mounting screws), mount the new pump, reattach the hoses (replace clamps if necessary), test for leaks, enjoy!

[Cheechako]

It can be air in the system, did you run out of water and then refill? If it's pumping water, could also just be the pressure switch on the pump. However is water flow is significantly lower than it used to be it could be the valve set in the pump. What brand of pump? Is there an accumulator in your system?

[Waverly]

This has happened to me on my Beneteau Oceanis 38 there is a screen before my pump and tank that got clogged due to algae / mold that grew while it was on the hard. Cleaned the tank and screen and has been fine since.

[Brewgyver]

I would just add that in many (most) installations, you won't find any valves to isolate the pump, so when you disconnect the suction side (hose coming from the tank(s), you'll have a flood if you don't empty the tank first. Simplest way to deal with that is to have a small thru-hull plug in your hand
http://www.defender.com/large/401095_l.jpg
to stick into the end of the hose while you swap out the pump.

[Capt Jerry]

One caveat, when I replaced my freshwater pump I up-graded to a higher gpm pump. Short story, it was too much for the system and never worked right. It would pulse on and off all the time. I went back and bought another pump just like the original and it works perfectly.

[Noisykate]

We had a similar sounding problem - the solution was to replace the accumulator. It was not holding the pressure it should, and the pump was then cycling on and off much too frequently. Easy job, cost about £35 diy.

[CarlF]

10 years is good service. Even if it wasn't broken, it would be approaching it's useful life.

Remember that a higher capacity pump will empty the water tank faster when a guest leaves the faucet on. I use a relatively small 3 gpm pump (Flojet) for this reason. About $100. Stay away from the variable pressure pumps. Many have had reliability problems.

Look at how the hoses connect to the current pump. Most have some sort of clip fitting so it's really easy to swap out. Get a pump that has the same connectors. Changing plumbing is a pain in the neck.

Also look at the wires. You will most likely have to crimp new wire fittings. If you aren't used to putting on crimp fittings get some spares and practice with some spare wire. The simplest thing is to cut the wire and use a heat shrink butt splice. With a good crimp, you should not be able to pull the wires apart. Get a selection of crimp fittings for different wire sizes. Most likely this job will call for a "blue" fitting size. Get a good marine brand crimp fitting - like Ancor. Also get a good "single crimp" crimper as they work better than double crimp with heat shrink fittings. The tool will last your lifetime so don't go cheap. Maine Sail has recommendations. Ancor is always safe.

[Alita49DS]

If it is a Jabsco pump the good news is that the seal service kit is about a quarter the price of a new pump. Both extortionate.

The other good news is that servicing the thing is not difficult as it is a primitive device.

However, the bad news is that the instructions that come with the kit are a disgrace. Jabsco UK agree but say not us, the Americans.

So, before you take the thing apart grab your mobile phone (who bothers with a camera these days?).

1. Photograph the base. In particular one of the protruding threads.
2. Once you have separated the pump from the motor and lifted up the diaphragm be careful not the dislodge the innards. Photograph the two circular valves making sure you have a reference point.

Why? In relation to the above:

1. Normally you would tighten a seal to make it waterproof. Right? Wrong. If you over tighten the four long screws the thing will not only leak but make a racket as the screws hit the bulkhead. So count the threads that went through before.
2. The inlet and outlet valves are the same and there is no way to tell which way up they go unless you have a record.

The primitive beast only has a flow rate of 10 to 13 litres a minute. If you are lucky.

I wonder who designed the thing - and when.