main water pump fault

[robkg]

My fresh water pump is a jabsco variable speed one. It has worked fine for the last six years but has now developed a problem.

The symptom is that the pump will start to run very gently (slowly) for a second or two, every 30 seconds or so.

I initially thought this meant that I had a leak in the pipework somewhere, but after some investigation I now think it is a problem with the pump internally. I first checked the bilges at the lowest point on the boat (after the pump had been powered for three days) only to find them bone dry. I then closed the valve located immediately downstream of the pump, isolating the whole of the boats pipework, with the result that the pump still ran intermittently but for even shorter bursts and longer gaps. I concluded that the pump has a fault, and wondered if water is leaking back through a non return valve within the pump itself.

Does this sound right and if so what can I do to rectify the problem?

[blackrose]

That can happen. I'd call jabsco (or their distributor Mack engineering) and see what they say. If the NRV comes off the pump then changing it seems like it might be the solution.

 

http://www.mackengineering.co.uk/categories/JABSCO-PUMPS-%26-PRODUCTS/

Edited May 31, 2015 by blackrose

[Tony Brooks]

Or even fit a plumbers NRV in the inlet line. I find flap types best as they do not inhibit self priming as a spring loaded one might.

[smileypete]

Been one report on here of brush bristles in the pumps valves, like from repainting the water tank.

 

Odd that it runs for shorter burst and longer gaps when the downstream isolator is closed...

 

cheers, Pete.

~smpt~