R27 No water pressure with pump constantly cycling.

TomHall

Active member
Joined
Oct 19, 2020
Messages
34
Fluid Motion Model
C-28
Hull Identification Number
FMLT2738A111
Vessel Name
Dawn Patrol
2011 R27

  • Fresh Water pump runs non-stop.
    A trickle at the head faucet.
    A drip at the gally.
    Tons of presser at the city water connector - when I remove the fitting (unscrew four screws) and pull the hose from the back (undo the hose clamp etc).
    Plenty of pressure at the hot water heater.
    Plenty of water flows from the tank to the pump.
    Pump is new.

Any Ideas?
 
Faucet screens are plugged.
 
If the faucet filters were plugged the water pump would probably not run constantly. I suspect air is getting into the lines, and or, a leak.
You say the pump is new. Have you double checked that your connections are tight? If you have a Johnson pump, there is probably a filter attached. Is the filter housing cross threaded or loose?
Is there good water pressure if you disconnect the main line leaving the pump before it branches off to the other lines?
 
I have good pressure leaving the pump.
I have pressure at the hot water heater.
I also do not have any leaks in the system, I checked for visible leaves and the bilge is dry and water level is staying the same on the tank guage.
 
Why was the pump changed for a new one?
I would disconnect the water lines at the faucets and check the water flow at that point.
Running constantly leads me to think there is an air leak. Is the O ring in place on the pump filter?
 
Brian B":ouhncpon said:
Why was the pump changed for a new one?
I would disconnect the water lines at the faucets and check the water flow at that point.
Running constantly leads me to think there is an air leak. Is the O ring in place on the pump filter?

I thought the pump was the issue, so I changed it out and changed the rubber gasket o-ring on the pump filter too - it is providing pressure to other areas of the system - like the hot water tank and further down the line and the garden hose fitting (street water).
 
Not sure what you mean that it is providing pressure at the garden hose fitting. That has a check valve on it. There should be no water flow coming out of the street fitting so this could be the issue. When you say the pump runs constantly, do you mean when you are using it or when everything is turned off? When using i, then it is sucking air in and it may be the gasket at the pump screen is not seated properly.
 
I removed the city water fitting, pulled the hose off the back and it has pressure from the pump.

It runs when I throw the switch and never build pressure enough to stop running.
 
Can you see air bubbles through the plastic cap on the filter when it is running? If you can it is sucking air.
 
Hi TomHall,

If the pump runs constantly, you most likely have a leak at some point in the system. Once the system is fully pressurized, the pump will stop. If it does not stop, pressure is getting out of the system in the way of losing water. The only other issue could be that the impeller in the pump is not functioning. Although possible, it is probably very unlikely though, since you said the pump was new.

Thanks,

Ralf
 
Could be a bad pressure switch on the pump but unlikely if it is new. Any chance that your boat might have a valve on the supply line from the tank that got turned off?

John
 
Thank you everyone!!!

I have cleaned the faucet heads and went step-by-step through the system. The issue is on the supply side of the pump. I am not getting enough water to the pump itself.

That should be a straight line coming directly from the water tank, correct?
 
The supply line should go directly from the tank to the strainer and into the pump. Occasionally owners have added a valve in that line (as we have done) to facilitate maintenance. If your tank vent somehow got plugged it could cause the problem you are experiencing. You could remove the fill cap and then try the pump to test that theory. Also, with the cap removed, you could try blowing air back through the supply line and into the tank to see if there is a blockage.

John
 
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