Pump troubleshooting
My pump runs but there’s no water pressure
A pump that’s clearly running but delivering little or no water is almost always a suction-side problem: it’s spinning, but not moving water. Work through it from the water source forward and you’ll usually find it quickly.
The usual causes
- Lost prime (air trapped in the pump housing)
- An air leak on the suction line
- A blocked inlet filter or foot valve
- An empty tank, or a water level below the outlet
- A closed or partly closed isolation valve
- A blocked or kinked suction hose
What to check
- Check the tank actually has water and the level is above the outlet.
- Check the inlet valves are fully open.
- Check and clean the inlet strainer or filter.
- Re-prime the pump: fill the housing and suction line with water through the priming port before restarting.
- Look for air leaks on the suction side. Any loose fitting on the inlet lets air in and stops the pump drawing water, so tighten fittings and check seals.
Safety: Never run a pump dry to see if it catches. Running without water quickly damages the seal and can burn out the motor.
Common questions
What does losing prime mean?
It means air has got into the pump housing or suction line, so the impeller is spinning in air instead of water. Refilling (priming) the pump and sealing the leak fixes it.
The pump was fine yesterday, why now?
A dropped tank level, a foot valve that has started leaking back overnight, or a fitting that has worked loose are the common overnight changes.