Fresh water pump

[BonesD]

2nd question of the day. I can hear my fresh water pump cycling every couple hours. Is this normal or should it hold pressure indefinitely? No faucets dripping or leakage I can discern. I don’t mind it but I can see where it could be a battery drainer in the right circumstance.

 

[jungpeter]

Hi BonesD. You've got a leak somewhere on the high pressure side of your water pump. Keep looking! Battery draw is the least of your issues here, as a water leak downstream of the pump can lead to a host of other issues, such as mold and rot in the most inopportune places, and water where it doesn't belong.

Regards,

Pete

 

[BonesD]

Well, that’s not something I Wanted to hear!
Thanks��

 

[Irish Rambler]

I can only concur. I had a similar problem and it took me a while to find it but I'm glad I did because on my search I discovered water build-up behind one of the stringers which over time would have rotted the bottom of a nearby bulkhead. Found the leak, changed the fitting and secured the pipe with a plastic clamp, then drilled a hole through the stringer and tapped in (tight fit) a short piece of stainless tube to act as a liner, dried the bottom of the bulkhead with an electric fan heater,
Job done and piece of mind.

 

[FF]

A leak would be one cause , but most folks use city water which can be quite hard.

This can create deposits on the pump check valves , so a short run every few hours is hardly uncommon.

Simplest test is to purchase a brand new pump and toss it in.

If the short pump run continues,,, look for the leak in the system.

Flush the old pump with CLR or similar and keep it for an onboard proven working spare.

 

[Irish Rambler]

If you use city water that's hard I would suggest fitting an electronic water descaler, we've had one for years and they make a big difference.
Shower heads stay clean, kettles, calorifiers and better for easing skin irritations.
There are several types on Amazon and the only proviso I would make is to take a larger size, i.e for a 3/4 bedroom house type is suitable for up to 50'.

When you refill with water put 1 tablespoon of Bi-Carbonate of soda in a quart jug, fill with warm water to dissolve it (be careful it will foam up) when its fully dissolved add it to your water tank as you fill with a ration if 1 jug to 60 gallons of water.
There's no after taste, it eases stomach upsets, your tanks and pipework will be sterilised and your veggies cook better and its dirt cheap and easy to do.
Apologies for the spelling it should read Descaler.

 

[DCDC]

We also had a water pump cycling every few hours. Could not find a leak so assumed it was the check valve leaking back. We have parallel pumps, each with a check valve, so I switched to the second pump - same cycling. Both check’s could have been leaking but not likely.

Went over system again and noticed that a hose which runs from the hot water heater pressure relief valve to the bilge was hot. Removed the hose and founds the PRV dripping.

The PRV is set at 75 psi, which is lower than residential heater valves. I don’t have a spare, so just valved out the heater. Fortunately the weather is warm enough that a cold shower is OK.

Good luck with your troubleshooting.

 

[BonesD]

Thanks I will start the search!

 

[Ski in NC]

My FW pump was doing that. Annoying. Went all through the boat and found zero leaks. So figured it was the FW pump itself leaking back internally.

For giggles I opened up a couple of spigots and let the pump run the entire tank down, hoping it would flush whatever crud was caught in the check valve.

It worked!! I refilled the tank and no more pump cycling.

That was like five years ago. Has not done it since.

 

[BonesD]

I took a look at the pump today. Sure Flo electric pump sitting on top of a big silver canister from Sure Flo also.
I’ve had this boat for months but just started using the water the other day so I am feeling my way along.
Laying next to the pump is a Sure Flo check valve with a piece of water line attached to each end. It’s easy to see that it was installed before. I don’t see another in the water system nearby so I’m thinking this was removed and not replaced.
If I blow in one end it is air tight, the other if I blow pretty hard it whistle but very restricted. Of course my lungs don’t put out that much pressure. I don’t know if that is a valid test but it looks like Walmart sells the valves.
Where should it be placed and what is the big silver sure Flo canister?
Thanks

 

[tiltrider1]

The canister is an accumulator tank. It helps prevent pump pulsing.

 

[tiltrider1]

You don’t need to put the check valve back in. Pump has its own internal check valve.

 

[HopCar]

I agree with FF. If you can’t find a wet leak on the pressure side, change the internal valves in the pump. When the valves go bad the water leaks back through the pump to the tank side. If it’s only running once in a couple of hours, the noise doesn’t bother you, and you don’t have water leaking out somewhere, I’d ignore it until it gets annoying.

 

[BonesD]

Thanks, I read up on it a bit. If the internal check valve is failing can an external take its place? Is the check valve in the pump or the pressure canister?

 

[Comodave]

I would just replace the check valve in the pump, not too hard to do. You can lay paper towels around under the plumbing to help find leaks. Even if it dries out the paper towel will show that it was wet.

 

[BonesD]

Sounds like the best course. Thank you.

 

[Lou_tribal]

I got a similar issue few years back and was not able to find the leak until one day I was lucky enough to get my nose on it. It was a very tiny leak from my water neater that was dripping 1 drop every 10 to 20 seconds that was slowly going down under the water heater and was not visible. Even few drop was lowering the pressure in the line and resulted in the pump running few seconds every hours.

L

 

[BonesD]

I will take a look tomorrow. Thanks
I’m finding all sorts of stuff hidden away down below while sorting this out. It’s been like a treasure hunt��

 

[BonesD]

I just noticed on the bulkhead by my water system is a a horizontally
mounted clear plastic vessel thing a bit like the glass bowl on the bottom of a fuel filter. I unscrewed it a bit and water started to flow so tighten it back up. I can’t see the water in but I’m sure it’s there. It’s n line between the water tank and the pump. I don’t see any filter in it. Maybe and inch and a half a n diameter and sticks out 3 inches or so. ?

 

[Bacchus]

Thanks, I read up on it a bit. If the internal check valve is failing can an external take its place? Is the check valve in the pump or the pressure canister?

I'm not positive but my thinking is external check valves are used to protect the pump if shore water is higher pressure than pump rated for.
The pressure sw will turn the pump on if it doesn't see sufficient pressure.
So, IMO you would still get pump cycling unless you also mounted an external P Sw on the high pressure side of the check valve.
Repair the pump!

 

[DCDC]

I just noticed on the bulkhead by my water system is a a horizontally
mounted clear plastic vessel thing a bit like the glass bowl on the bottom of a fuel filter. I unscrewed it a bit and water started to flow so tighten it back up. I can’t see the water in but I’m sure it’s there. It’s n line between the water tank and the pump. I don’t see any filter in it. Maybe and inch and a half a n diameter and sticks out 3 inches or so. ?

There is a similar filter upstream of our pumps. There should be a screen in it.

 

[BonesD]

Will do!

 

[DCDC]

A note about the suction side of water pumps. Our pump is above the tank level so the pump has to prime itself to function. If it can’t self-prime you have to manually add water to the suction side to fill the line with water. Without proper valves and a way to add water this could be difficult.

If you remove the strainer bowl and your tank is below the pump, you may lose the prime. A valve to block in the prime would help. Also helpful is a strainer bowl mounted upside down so it can be filled with water before screwing it on.

Good luck.

 

[Ski in NC]

Do the rapid pump flush like I posted a way back. Cheap and easy and worked on mine.

 

[BYNW]

If you have no leaks, it may be related to a bad pressure sensor on the pump.

 

[Halinbrier]

Check the pressure relief valve on the hot water heater. I had a similar issue and found mine was leaking a small amount of water but just enough to cause the fresh water pump to cycle periodically.

 

[akflyrod2]

Good evening, I can tell you what caused our similar issue, a slow leak at our hot water heater fitting. Over time it rotted a floorboard out and caused the tank to show rust. It was very hard to see so it went undetected for some time. Good luck on your hunt.

 

[RickyD]

I had the same problem on my last boat. The PO had plumbed in a fresh water engine flush system. It worked great, only one day I started hearing the water pump cycling like you. I searched every where for a leak, to no avail. Then I bumped a shut off valve in the flush system and the pump went on. I must have bumped that valve before and cracked it open ever so slightly. Problem solved.

 

[Lou_tribal]

So did you find the source of your leak?

L

 

[RickyD]

So did you find the source of your leak?

L

If you are asking about my story, yes, it was leaking into the engine flush system because the valve was slightly knocked open.