Fresh water pump pumps water but wont stop running.

Marcdohc

My 05 300 has another minor issue, Should I replace this pump? My fresh water pump pumps water just fine but wont stop running. I have run all my faucets for over an hour and unscrewed the outgoing water line to bleed the system. Am I missing something? Thanks in advance, Marcdohc

Britinusa

Maybe the micro switch on the top of the pump is stuck, after taking mine apart i realized that this switch is what turns the pump on, when the pressure drop's there's a diaphragm than lowers under spring pressure and this activated the switch to turn the pump on, maybe yours is jammed or shorting out?

Handymans342

You have a leak or the pressure switch at the pump is bad.

Marcdohc

Thanks guys, I'll go check it out.

MarkB

Is there a leak in the system. If the water pressure is low due to a leak it will keep running.

LaRea

Make sure the drain valve on the water heater is closed.

explore7425

A clogged screen will also make this happen. Take it out and check it. I have had this problem. The screen was clogged but you couldn't tell from looking at it. It was like a clear scum that built up on the screen. Clogged filter = low pressure=pump running. 

Marcdohc

hmmmm, was going to order a new pump. I'll take it apart and sea.

terrypage

I had this problem recently.  Eventually we found the leak coming from the cold water tap in the shower cubicle basin, leading to water collecting forward of the mid bulkhead and then discovering the failure of that bilge pump.   Big problem now sorted.

MajorAppeal

Did you ever get this resolved? This just happened with mine today, would like to hear your outcome.

rasbury

Only reason it keeps running is its leaking somewhere...

J3ff

rasbury said:

Only reason it keeps running is its leaking somewhere...

nah, the pressure switch goes bad on these things all the time and then the only thing they are good for is a raw water washdown.. 

rasbury

I've never had a problem with mine other than replacing the whole pump.

Liberty44140

Ha, yea don't bother with rebuild. The kit is so close to the cost of new better to just replace. 

Ian

Check the seal around the filter that air isn't being sucked in.

howardrams

Some models have the pressure switch on the end of the pump and are easy to change without the whole pump.

MarkB

Definitely a leak, either on suction side drawing in air, or on discharge side leaking water.  Do you have water coming out of your taps without any air pockets?