Question
We installed a Flotec lawn sprinkler pump to draw water from a retention pond to run sprinkler system. Pump will work and sprinkler work when hose hooked up to prime outlet, but will not draw water from pond. Quits working as soon as hose turned off. Tried attaching hose directly to input but water will not go through pump. Acting like there is a blockage, checked, but couldn't find anything. Tried replacing check valve, but that didn't work.

Answer
Hi Doug

Irrigation pumps are relatively easy to troubleshoot if you understand how they work and under what conditions.  If the water from the pond doesn't get to the pump, then there's likely an issue with the suction line.  First check the prime plug on the pump - unscrew it and check for water inside the volute (the impeller housing).  A good prime is the key to good performance.  Check all connections and fittings on suction line and ensure air tight connections.  Check the foot valve and, if there's one installed, check the basket or filter to ensure it's clear of debris.  I know it sounds elementary, but ensure the foot valve is installed properly.  If it's on backwards, it won't allow water into the suction line so make sure the flow indicator points towards the pump, not the pond.  Also check it for defects - a leaky foot valve or check valve will prohibit proper priming.  Check the pipe itself for cracks or debris plugging the line.

Ensure there's a slope in the suction line from the pond to the pump.  Straight horizontal pipe runs tend to trap air creating an air lock.  Another thing to consider is the vertical elevation or distance from the surface of the pond to the eye (or centre) of the impeller as well as the length of pipe from the pond to the well.  The height, or elevation shouldn't be greater than 20 feet for a 2 HP pump.  If it is, you may have to consider a submersible pump instead of a centrifugal end-suction type for suction lifts of greater than 20 feet, depending where you live.

One more thing to consider is line voltage.  Make sure the electrical supply is providing the minimum required by the manufacturer to the pump.  Check with a volt meter at the pump terminals.  It's fine if the manufacturer's minimums are available at the pump.

Hope this helps.  Let me know how you make out.

Tony