How to test for a failed pressure switch (12V pump)

Testing for pressure switch failure is an easy operation. If you have a 240 volt model pump print these instructions and give them to a qualified electrician with the pump for them to check it for you.

1. Disconnect the pump from the power supply.

2. On the end of the pump end is a black square box. This is the pressure switch. With a Phillips head screwdriver remove the one screw in the middle and take off the cover.

3. Slide out the two wires from the pressure switch and touch them together.

4. Connect the pump to the power supply again. Don't worry if water is not connected - the pump can run dry for a short period. If the pump motor runs disconnect immediately from the power supply.

5. If the pump now runs then you need to replace the pressure switch. If the pump did not run, then the problem lies elsewhere.

If your pump is newly installed and you heard it running in a noisy or bumpy manner then you probably have a pump which is too big for your system. This can be fixed by adding a pressure tank, dropping the PSI on the switch (see related FAQ) or by using a different pump.