Hi All,
Shurflo 4048 Fresh Water Pump loses prime at 1/4 tank. Strainer is clean. No apparent leaks.
Ideas?
Thanks
Don
Is that 1/4 tank from a visual check at the tank or through the monitor?
Mike
Yup, when you look in the pump's pre-filter, do you see water or air when this happens?
1/4 tank is visual on the tank.
No air in the strainer.
Don
That is strange. With no air in the suction strainer and water in the tank then this is more like the pump just quits delivering water. Like I said this is strange if you lose prime you should have found air somewhere in the pump suction side. Now it could be something left in the tank during production that gets sucked into the suction piping once the tank gets low causing a restriction. The thing is if it was a loose piece of construction material seems like it would get sucked up at various tank levels rather than just at 1/4. If it was a bad check valve in the pump you would see pressure/volume problems no matter the tank level. More brain time is required till I come up with something else.
Mike
Fill solenoid off?
My fresh water tank has a small cone shape sediment filter 1/2"x 2" that slips into the 1/2" female outlet spin weld fitting. You would have to undo supply line connection to pump at the tank and use a curved pick to pull it out if you have one.
On my coach the pump is at the bottom of the tank so the water gravity feeds to the
pump so if your system is the same I would think there is a blockage some where.
Blow the line back into the tank to see if it is opened.
Fill the tank to half full. Check the flow at the kitchen. If the flow is adequate check the plumbing from tank to pump. If no issues are found, make sure the pump is not pumping back to the tank, then think pump.
I think I figured it out. Prior to my last trip the water fill valve failed, and I replaced it. During the trip the pump would come on every minute and cycle for 2-3 seconds, so we turned the pump off when not in use. Pump would lose prime at 1/4 tank.
When I got home, replaced the defective water fill valve. Pump no longer cycles. Just drained tank down to below 1/4 tank and the pump seems to work OK. Next trip scheduled for later this month will tell.
So, it seems like the defective water fill valve was the culprit.
Make Sense?
Don
Sounds reasonable. On the older coaches (like ours) that have a manual fill valve, if the fill valve is left open and the water pump is turned on, the pump will run continuously but the water system will not have any pressure. The water just goes in a closed loop from tank to pump and back into tank. Has caught many new owners by surprise when they experience mysterious loss of water pressure. A gentle suggestion from Forum members to "Try closing the fill valve" often solves the problem. Perhaps you had a similar condition that was cured by replacing the fill valve?