How To Replace a Pool Filter Drain Plug on a Cartridge Filter

Step 1

The first step is to shut off power to the pool pump at the circuit breaker. This will stop the flow of water through the pool filter.

Step 2

Next you will have to relieve the pressure that has built up in the pool filter. To relieve pressure turn the air relief valve on top of the filter counter clockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

Step 3

Remove the drain plug by turning it counter-clockwise.

Step 4

When you buy a drain plug, it will come with an O-ring. Make sure that the O-ring is not torn or cracked and place it onto the drain plug as far as it will go.

Step 5

Apply a thin coat of a silicon based lubricant onto the O-ring.

Step 6

Screw the drain plug clockwise onto the filter and hand tighten.

Step 7

Turn on power to the pool pump to repressurize the pool filter.

Step 8

The air relief valve should still be open. As the pressure builds, air will be released through the relief valve. When water starts to spray out of the valve, turn the valve clockwise to close it.

Step 9

Check the pressure gauge. It typically reads between 10 - 20 psi but this will vary according to the make of pool cartridge filter or its age.

Step 10

Check the drain plug to make sure it is not leaking.