SMA 5301793, Owner'S Manual

Page: 6 / 10

Page 6
Cleaning the Check Valve
:
If you’re experiencing little to no pressure or the pump is not priming and you’ve
checked your filter screen and it’s clean, and you’ve gone through the other
trouble shooting tips, you may need to clean the check valve.

Remove the head of the pump, which is held on by 7 screws.

The first piece inside the head of the pump is called a check valve, it’s the part responsible for building up
pressure and pumping water/solution through the lines.

Clean the check valve under hot, soapy water (such as a good grade dish soap).

Give it a very light scrubbing with something like an old toothbrush, something with soft bristles.

Then let it soak for about an hour or so in the hot soapy solution and replace in the pump and reassemble the
pump.
Most times this will restore most, if not all of the prime of a pump.
If you’re still having issues with pressure after this step, it would be recommended to replace this part.
Checking the Pressure Switch
:
If your motor is not running and you’ve checked the following: for loose wiring
connections, fuse, the switch on the lead wire was “ON” and made sure you were connected
to a fully charged battery and everything is fine, but the motor won’t run, then it’s time to check
to see if the pressure switch is bad.

Remove the cover off the 1” square box (pressure switch) on the head of the pump, the
cover is
held on by one phillips-head screw. This will expose the two red wires.

With the pump connected to a good 12 volt power source and everything on.

Slip the two red wires off the terminals and touch them together.
If the motor runs, it means the pressure switch is bad and needs to be replaced.
If it still doesn’t run, try bypassing the switch in the lead wire or using another lead wire. Even
if a tester shows power to the pressure switch, it still could be the switch in the wire that is
causing the problem. If still not responsive, use a voltmeter or electrical tester to make sure
you are getting power to the head of the pump, as it could possibly be something in one of
the wires or even the lead wire assembly may need to be replaced.
Warning: It is NOT recommended to run the pump this way, as the pump will
continue to run and not shut off.
This could result in blown hoses when all discharges are closed.
Also, this could result in premature failure of the pump completely.