Fresh water pump keeps running

[Pilot]

Just filled up the water tank and now pump seems to just continue running and little pressure for water for sink faucets, etc. I've checked and no apparent vacuum leaks that I can see.
Is there an easy way to diagnose this?

Thx

 

[Lazy Daze]

I would first monitor your water tank for a while (with the pump on but no faucets turned on) and see if the level is dropping (indicating a leak somewhere). Here's something you can do... remove the output line from the pump... put a short length back on with a cap on it/plug. If the problem stops, the issue is AFTER (downstream) the pump. If the issue continues, the problem is the pump or upstream. That will at least help you narrow it down quickly.

EDIT:

Oh...
-- Have you checked the filter?
-- How long has it been since you used your tank?
-- Have you been using the city water with no issues?
-- Remove one of the aerators and see if the flow increases.

 

[Little Ducky]

Check for leaks everywhere.

I had a WTF moment at the beginning of the year when I filled up the water tank for the 1st time and the pump would not turn off...... I quickly realized the transom shower was left on and filling up the transom locker with water.

At the end of last year the pump wouldn't turn off when I was winterizing and I found the diaphragm had hardened to the point it would not pump any longer..... after getting a replacement diaphragm all was well in the water department.

 

[Pilot]

I would first monitor your water tank for a while (with the pump on but no faucets turned on) and see if the level is dropping (indicating a leak somewhere). Here's something you can do... remove the output line from the pump... put a short length back on with a cap on it/plug. If the problem stops, the issue is AFTER (downstream) the pump. If the issue continues, the problem is the pump or upstream. That will at least help you narrow it down quickly.

EDIT:

Oh...
-- Have you checked the filter?
-- How long has it been since you used your tank?
-- Have you been using the city water with no issues?
-- Remove one of the aerators and see if the flow increases.

Thanks, will try those options

 

[be_prepared]

There is a little screen filter/strainer that should be between the tank and the pump. It's a clear housing usually that screws off. I had my pump running and running last weekend, with very little water flow. Turns out that the little filter was filled with black goop. I had a couple weeks where I didn't use the onboard water much, mostly shore water at the marina, so the water sat in the tank, and when we were on the hook for a day with 8 people aboard, all the yucky stuff from the bottom of the tank was drawn through this little strainer to the point that it was clogged, and only a trickle of water was getting through. I'm glad I found it before I burned out the motor. After clearing the goop, all was well again, or at least I thought it was. I checked the filter again after a couple more hours of random use, and although not blocked, there was black stuff building again.

I picked up a bottle of water tank flush at West Marine today at lunch, and that will be a project one night this week. There must be a layer of stuff settled into the bottom of the tank. Time to flush it out.

 

[Blueone]

I just had a very similar situation...If you have a similar pump. I had a loss of pressure but not a lot and pump wouldn't shut off.. My $250 pump replaced last year could not have been the problem. So I ripped everything apart...followed every line... Cleaned every possible passage... Called ...emailed Shurflo relentlessly to no avail... So I ended up messing with the pressure Allen screw adjustments on the pump and things got better but still wouldn't shut off... I ended up buying a $100 lower end to the pump which included the pressure switch and the problem went away. Not sure this is your solution but if you exhaust everything maybe the next option