TROUBLESHOOTING: Pump Priming

31st May 2017

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Pump Priming.  All you need to know!

Some difficulties may be expected in priming the pump at the commencement of the season. The following procedure is suggested:

1. Make sure that the pool is full. It is extremely difficult to prime the pump if the pool is less than three-quarters full.
2. Close all the valves in front of the pump.
3. Set the multiport at ‘waste’ (or backwash).
4. Remove the top of the coarse strainer and fill to the top with water. Replace the top firmly.
5. Switch on the pump and immediately open one of the valves. After a minute or two, the pump should start pumping and the pressure gauge will rise. If this does not happen within three minutes, switch off and go through the procedure again. When the filter is operating satisfactorily with this one valve open, the second valve can be opened very slowly. If the pressure gauge immediately drops to zero, shut off the second valve until the pressure has risen to normal and slowly open again. Continue in this manner until the gauge is constant with both valves fully open.

If the pump will not prime, there is probably an air leak in front of the pump. It could be that:

1. The top of the coarse strainer is not sealed correctly.
2. The socket union between the pump and the valves is not fully tightened.
3. The rubber gasket has not been replaced in the socket union.

On older pumps, if the pump priming is difficult, there may be a leak between the pump and the pump motor. A worn pump seal will suck air and make priming difficult and should be replaced.