Water pump starting for a split second every so often

[madder do ee]

Every now and then my water pump that is situated next to the water tank runs for a few seconds. And the regularity of this is increasing. I'm concerned there is a small leak somewhere because the pump runs when you open a tap, flush the loo etc. so  I can only think, I'm losing a very small amount of water somewhere that is causing the pump to run. as it getting more frequent I am the leak is getting worse. 

I would appreciate your thoughts.

[Tracy D'arth]

2 minutes ago, madder do ee said:

Every now and then my water pump that is situated next to the water tank runs for a few seconds. And the regularity of this is increasing. I'm concerned there is a small leak somewhere because the pump runs when you open a tap, flush the loo etc. so  I can only think, I'm losing a very small amount of water somewhere that is causing the pump to run. as it getting more frequent I am the leak is getting worse. 

I would appreciate your thoughts.

You have either a leak which needs fixing quickly before you sink or the valves in the pump are letting water run back. Are you sure its not a tap, loo or shower dripping?

 

Check the pressure release valve on your calorifier if you have one. It should not be passing water.

Edited June 5, 2023 by Tracy D'arth

[Bod]

Check around the pump for wet as well, it might be the pump body leaking.

Also check the bilge for water, the leak will all go there, and it needs removing asap.

 

Bod

[ditchcrawler]

33 minutes ago, Tracy D'arth said:

You have either a leak which needs fixing quickly before you sink or the valves in the pump are letting water run back. Are you sure its not a tap, loo or shower dripping?

 

Check the pressure release valve on your calorifier if you have one. It should not be passing water.

My pump was leaking back, proved it by closing the feed valve but you cant draw any water while doing the test

 

[blackrose]

It doesn't sound like you have an accumulator in the system otherwise the pump would be running for more than a few seconds. It's actually easier to listen for leaks without an accumulator so I have an isolator on mine.

 

The other thing it could be is your calorifier cooling down (assuming you have one), decreasing pressure in the system which the pump then has to compensate for.

Edited June 5, 2023 by blackrose

[Tony Brooks]

4 minutes ago, blackrose said:

It doesn't sound like you have an accumulator in the system otherwise the pump would be running for more than a few seconds. It's actually easier to listen for leaks without an accumulator so I have an isolator on mine.

 

The other thing it could be is your calorifier cooling down (assuming you have one), decreasing pressure in the system which the pump then has to compensate for.

 

and if you do have an accumulator, it may have lost its internal air pressure.

[Chewbacka]

1 hour ago, ditchcrawler said:

My pump was leaking back, proved it by closing the feed valve but you cant draw any water while doing the test

 

I did that on my system, but a word of caution, if you have one on those little plastic topped mesh filters on the pump feed then when you close the tank supply valve the small back leak through the pump causes the pressure to rise in the filter casing so it opens up and looses water, so the pump will come on.  But the filter leaking when the valve was shut proved it was the pump.

[JRT]

I had the same thing happen to me a while back, twice. The first time I discovered the housing on the pump had developed a leak and I had to replace the whole thing. The second time, I was braced for further expense but it turned out to be, as suggested above, a dripping tap.

[madder do ee]

Thanks for the help with this. It turned out to be a push-fit connector at the top of the calorifier. There is a drain-off, but I think I will have to get it to Syphon! and empty enough of the water out to change the fitting.

I have done plenty of domestic plumbing, but this will be my first time on a boat, 

[Tony Brooks]

Drill pump is your friend - pump straight overboard. If it is a vertical calorifier, and you leave the taps open and the pump off, you may not have to drain much water at all. There is no mains pressure or a header tank in the loft. If you do have a small header tank, it is for the central heating, not domestic hot water.