Bilge pump does not switch off

[westhinder]

My Johnson 750 gph bilge pump switches on when it detects water, but does not switch off automatically. The auto switch is an electronic one, not a float switch. There do not seem to be any moving parts. Is there anything that can be serviced, or is it just a throwaway item? It can be replaced separately.

 

[rogerthebodger]

The only think you could try is to clean the sensing electrodes and/or any much that is around the electrodes.

I changed my bulge pump switch to the pneumatic type ages ago as I was fed up with replacing the nodding donkey type and electronic type.

 

[V1701]

Does it not switch off at all or switch off and on perpetually? If the latter it's possible that what's left in the pipe rise draining back into the sump is enough to activate it again...

 

[PaulRainbow]

My Johnson 750 gph bilge pump switches on when it detects water, but does not switch off automatically. The auto switch is an electronic one, not a float switch. There do not seem to be any moving parts. Is there anything that can be serviced, or is it just a throwaway item? It can be replaced separately.

My bilge switch is a Whale sensor type, similar to yours, if not the same. I wshed the bilge out a few weeks ago and a couple of time the pump didn't stop running. Turning the supply off and back on stopped it. I cleaned the sensor (as Roger suggests) and it cured it.

 

[westhinder]

Thank you all.
I did clean the switch, but I will try again and do it more thoroughly.
The trouble is, if it keeps running, it eventually flattens the batteries. When I noticed the problem the pump must have been running a couple of hours and had already drawn 55 Amphrs. That was after a fierce storm, and I normally check the boat before and after a storm. If I hadn't done so, I would have had damaged batteries to boot.
@V1701: it just keeps running, it does not cycle on-off, there is a one way valve in the pipe

 

[gregcope]

@westhinder any joy?

Like others i would suggest a good clean.

 

[westhinder]

@westhinder any joy?

Like others i would suggest a good clean.

I won’t be aboard before the weekend, I’ll report back when I have a result

 

[Aurai]

A non return valve on the outlet worked for me

 

[westhinder]

A non return valve on the outlet worked for me

There is a non return valve in the outlet pipe, so I am certain the problem is not caused by water running back down into the bilge. The pump just does not switch off automatically. If I switch it off manually and then on again, it is ok. It starts automatically if I fill the bilge, drains it and then keeps on running. I am going to try cleaning the electronic switch thoroughly.

 

[westhinder]

A quick update: thoroughly cleaning the automatic switch seems to have done the trick. The pump switches off after it has evacuated the water.
Thank you for the suggestions.

 

[PaulRainbow]

A quick update: thoroughly cleaning the automatic switch seems to have done the trick. The pump switches off after it has evacuated the water.
Thank you for the suggestions.

Thanks for the update, glad to hear it's working.

 

[gregcope]

+1 Glad to know that fixed it.