Macerator pump running when water pressure switch activated?

[danstanford]

We haven't owned our 2000 290 for a year yet and last year prior to me draining the water system and opening all the thru hulls (including the macerator discharge) we had no problem with the water system. We would turn on the water pressure and the pump would run till it built pressure then shut off as expected. This year I discovered that what I thought was the water pump is the macerator pump and now it won't shut off because the pipe is empty I assume.
Does it make sense that both pumps turn on with the water pressure switch?

Dan

 

[RoyS]

No. Probably the macerator is only controlled by its circuit breaker. Shut it off until you need it.

 

[danstanford]

Thanks Roy, I know we didn't activate the macerator breaker and I know that the macerator pump shut off when we switched water pressure off so somebody has wired this up wrong somewhere. Given that the boat will be nowhere that using the macerator is legal I could just disconnect the pump for the time being. I used to think it was the water pressure pump so it never bothered me.

 

[Peggie Hall HeadMistress]

Sounds to me like somebody wired 'em both to the same circuit breaker.

You'll need to do more than just unscramble the wiring if you ever want the macerator pump to work again.
It needs a new impeller.

When an impeller pump runs dry (without any liquid going through it)--and yours has run dry quite bit, dry friction heat destroys the impeller. The motor will run, but the impeller can no longer pull (impel) anything through it. But you're in luck...your tank is empty and system is dry. Most people only find out their macerator pump needs a new impeller when the tank is full..

 

[Skipper]

We haven't owned our 2000 290 for a year yet and last year prior to me draining the water system and opening all the thru hulls (including the macerator discharge) we had no problem with the water system. We would turn on the water pressure and the pump would run till it built pressure then shut off as expected. This year I discovered that what I thought was the water pump is the macerator pump and now it won't shut off because the pipe is empty I assume.
Does it make sense that both pumps turn on with the water pressure switch?

Dan

I'm confused here.
You say the water pressure pump operated until pressure was built then it shut off on its own? Then when you run the faucet it cycles again?
That is the water pressure pump. A macerator usually does not have a pressure switch. If you supply power to it, it will run until you turn it off, or it dies.
The water pressure pump almost certainly has an internal pressure switch. It's not possible to activate another appliance with the switch, without some very strange surgery or series wiring.
Are you saying both pumps run at the same time until pressure is built?
Last, have you physically identified the 2 pumps? -labels, plumbing routes, etc.

 

[danstanford]

Last night I traced the wires and found that somebody had moved the feed line for the macerator to the water pressure switch so activating the water pressure made both pumps power up. Once I moved the wire back to the right breaker switch all acted as expected. Skipper, I couldn't figure out why the macerator pump would not have run constantly last year pointing this problem out earlier but the answer was that there was liquid in the holding tank last year and not this year. To prove this I pumped a couple of toilet bowls full of water and then as the macerator lines filled with that water the pump shut off which does indicate mine has a pressure switch.
In any case, now it doesn't shut off because it doesn't start since it is once again back on its own switch. All is well, and thanks for the help folks. Now I just have to figure out why the electric water heater isn't working....