My fresh water pump does not shut off

[Eren]

My boat has a 24V Gianneschi Ecoinox 2 fresh water pump. When I turn on a tap, it starts working but does not shut off when I turn the tap off. It only shuts off when I start the generator. I had faced a similar situ at my previous boat only when the batteries were drained. It looks like the pump cannot gather from the batteries the voltage that it needs for shutting off and can do it only via generator. However this time my battery voltages are quite OK. Have you experienced something like this before? Do you have an idea what should be adjusted or replaced?

 

[sailorman]

what pressure is the accumulator diaphragm set at

 

[Eren]

I have a manual one with a screw to adjust. Ao I don't know the exact pressure. But it is not touched in the meantime for sure. Should I try to adjust it?

 

[SEARANGER ANCASTER]

Pump not producing enough pressure to fill accumulator and cut off pressure switch so could be pressure switch or more likely if you say it works with genny on , then the pumps somehow not getting full voltage from batteries ???. I would let a little gas out the accumulator via the schrader valve. Just a little though. This would make it easier for the pump to reach the pressure that the switch is set to. Or reduce the setting on the pressure switch.

 

[Eren]

Looks good. I will try that.

 

[Bilgediver]

Sounds like the pressure switch is set too high. This switch could be within the pump or elsewhere in the water circuit. Reset the pressure switch to a more suitable pressure . The accumulator is a passive device and is used to smooth the pump pulses and resetting its internal pressure may not help. and could cause it to not sufficiently smooth the pump pulses due to reducing its effective volume.

 

[JerryC]

Another job where a multimeter would come in very handy. Check voltage across battery then across pump. Repeat with genny on.

Electrical connections don't last too long in salt-laden air, ie in boat engine rooms and lazarettes. An apparently slight amount of corrosion can introduce enough resistance to limit the current, drop the voltage. so performance suffers. If you don't have a meter, you could pull off the connectors to the pump and pressure switch, have a good look for corrosion, then scrape / polish clean with wet n dry, then replace.

 

[Eren]

Letting the gas out did not solve the problem. Tomorrow I will check and clean the connections.

Thanks a lot for your suggestions and assistance!

 

[daveyw]

I suspect you have a dirty microswitch and it's the vibration from the generator that makes it work

 

[MapisM]

It looks like the pump cannot gather from the batteries the voltage that it needs for shutting off and can do it only via generator.

I don't know that particular model of Gianneschi pump, but I don't think it's double voltage (either 230V AC or 24V DC), or is it?
If it's 24V DC only, as any Gianneschi pump I came across so far, why on earth should the genset affect its operation?
Maybe you have a battery charger that goes on as soon as it's AC powered, but you should get exactly the same result when you are on shore power.
I mean, I'm puzzled by your specific mentioning of the genset, as if it would have "per se" anything to see with the pump.
Of course, if the pump behaves normally when you have the battery charger on (regardless of whether powered by genset or shore power), THAT can definitely affect the DC voltage, increasing it to 28+, as compared to 24 or even less when the pump runs on batteries alone...

 

[Eren]

I don't know that particular model of Gianneschi pump, but I don't think it's double voltage (either 230V AC or 24V DC), or is it?
If it's 24V DC only, as any Gianneschi pump I came across so far, why on earth should the genset affect its operation?

I have seperate pumps for use with 24V and 220V.

As far as I see, 24ish volt from the battery is not enough to trigger the switch (which I suspect to be faulty). 28V from the battery charger makes it do (yes, the charger comes in as soon as the generator starts running). I was not able to try it with shore power as I am away from shore power outlets for some days.

Now I use the pump by turning its switch from panel when we need. I will work on it when I will be back at the marina in 2 days. I will try all suggestions brought up here.

 

[jfm]

Hi Eren. I agree with bilgediver: letting gas out of the accumulator won't help, and you're creating an all new problem if you let too much out. Imho you need to adjust the pressure switch, or cure low voltage @ pump (bad connection?) if that is the problem.

(Separately and OT, I'm loving the Ultra and remain grateful for you massive help on it)

 

[Eren]

Thanks JFM. I am glad that you liked the Ultra. Ultra always gives me peaceful sleeps when I am at anchor.

Re pump, I have a spare pressure switch with me, tomorrow I will change it and will see.