Fixing the fresh water pump

[PJHoffnet]

Started using shore water a couple of weeks ago - turned off and vented when we leave the boat, so no pressure being applied when we're not around. Water pump breaker open whenever we're not there.

Wanted to test the water pump for pre-underways for an upcoming trip and no joy. Shore water off (did not vent), closed water pump breaker ... no pump noise and then about five seconds later pump breaker opens.

My trouble shooting plan of attack.

To make sure pump works. I plan on disconnecting pump output before pressure tank and allow to go into bilge.
- Step one: Attempt with power coming in normally, to the pressure switch which should sense no pressure (and thus be closed) since the pump discharge will just be into the bilge. If that works then I think there is something in the pressure tank that's screwy?
- Step two: If 'normal' power input doesn't work, assuming bad switch, will apply power directly to motor input, bypassing pressure switch. If pump runs, then assume bad pressure switch and replace.
- Step three: If 1 & 2 don't work, assume bad motor/pump and replace whole unit.

Am I missing something? Thoughts? Thanks in advance.

[mmwjr]

So the freshwater pumps breaker tripped? Sounds like an issue with the pump, was it working before adding city water?

I agree with step one. If it doesn't work I would bypass the pressure switch to see if it runs. Is there a check valve between the pumps output and the city water connection? Was the city water hose still connected? If so the system was probably still pressurized to city pressure. Did you open any faucets before turning on the pump?

[PJHoffnet]

Originally Posted by mmwjr

So the freshwater pumps breaker tripped? Sounds like an issue with the pump, was it working before adding city water?

-- Yes, the pump was working before adding city water ... and worked, underway, after disconnecting city water, up until the other day.

Originally Posted by mmwjr

Is there a check valve between the pumps output and the city water connection?

-- I don't know, have only traced the pressure tank output to the nearest bulkhead.

Originally Posted by mmwjr

Was the city water hose still connected?

-- Yes, connected, but not 'on'

Originally Posted by mmwjr

Did you open any faucets before turning on the pump?

-- Yes. After first attempt to turn on pump, with shore water 'off', but system not depressurized I thought that might be an issue so I depressurized the system by opening up a faucet until there was no longer flow.

[mmwjr]

Ok then I agree with following the three steps in your initial post.