Pressure Water, Black Grit

[WanderingStar]

Water pump runs on, delivers intermittently, with black grit in the water. Pump shot? I already tightened the connections, I don't think there's a leak. What else?

[RichH]

Probably one of two things - rust particles that have broken loose from a municipal water systems piping OR rock, etc. particles from a well that was drawn down 'too heavily'.

Take the pump apart and clean out all the debris in the CHECK VALVES of the pump. If the check valves are fouled, the pump wont make 'pressure'. Bench test the pump with the pump outlet 'deadheaded' or completely blocked ... if the the pump doesnt 'make pressure' either get new valves or get a new pump.

Then go and clean out your tank.

To prevent, ALWAYS use a screw-on 1,2µM canister filter **on the discharge of the dock hose** that you charge the boats tank.

Better is to get a 1,2µM canister NSF or FDA rated for "removal of oocysts" or "cyst removal" or "1,2µM to 99.9% efficiency" ... as still a significant portion of the USA municipal water supply is 'still' contaminated with such chlorine resistant 'cysts' - "giardia" or "crypto".

[BarryL]

Hi John,

What kind of pump? If it's a Jabsco piece of crap the pump is probably dead. I changed to a Shurflo this spring and so far it works. I have a spare if you want to install it and test it to see if it's the tank, lines, or pump.

Barry

[WanderingStar]

Rich, thank you, but It's probably not from the water. The grit is only in the head pressure water, not in the galley. All tanks were filled from the same hose. I think it might be some rubber part deteriorating.
Barry, thank you too. I actually have a spare pump aboard. I'll probably switch it today.

[svHyLyte]

If you have a water heater that includes an electrical heating eliment-such as the Raritan 1700 series--it will also include a zinc annode, generally associated with the water discharge side of the tank. The annode deteriorates over time, wasting away, and generating black gritty/flaky debris that accumulates on the bottom of the tank. When one runs the water, it appears as first a gray haze in the water and then dirt or grit. It is difficult to remove absent disconnecting the water discharge fitting and suctioning the tank out repeatedly and replacing the annode. Most people are unaware that this annode must be replaced a roughly 5 year intervals.

FWIW...

[WanderingStar]

Thanks Hylyte. No water heater either!

[PhilipStevens]

Originally Posted by WanderingStar

Thanks Hylyte. No water heater either!

Do you have a carbon/silver water filter in the line? If so, it could be carbon particles from a ruptured filter.

Just another thought

[WanderingStar]

Thank you all for you're help. The problem was much simpler: no water. The port tank valve was broken, the starboard tank empty. I was sure I had filled it before leaving the dock in may. But I filled it this week, it doesn't leak, and the water works. The grit was probably from the pump running nearly dry. Always check the simplest things first. This was the second time this month I've made a similar error. I hope I remember where I left the boat.