Use this procedure when the filter pressure has risen about 8–10 PSI above clean pressure, after heavy vacuuming, or when water flow has clearly slowed.
3-Way Suction Valve Reference
The handle points toward the line being shut off. Use the diagram as a reference for the normal store setup.
Before Starting
These checks prevent the common mistakes that cause lost prime, dirty return water, or equipment damage.
The 28 Steps
Check the filter pressure.
Confirm that backwashing is needed. A dirty filter usually reads about 8–10 PSI above its clean starting pressure.
Make sure the pump is running normally.
Check that water is moving and that the pump basket is not full of air.
Look at the 3-way suction valve.
For normal circulation, it should usually be at #4: half skimmer and half bottom drain.
Turn the pump off.
Do this before touching the multiport valve. This is not optional.
Roll out the backwash hose.
Point the hose toward a safe drainage area where dirty water can discharge.
Check that the hose is not kinked.
A kinked hose can restrict flow and make the filter or hose jump.
Press the multiport handle down.
Push the handle fully down before turning it.
Turn the multiport valve to BACKWASH.
Set the handle firmly into the BACKWASH position.
Keep the 3-way valve open to the pump.
Leave suction available. Do not put the 3-way valve in #1.
Turn the pump on.
Dirty water should begin flowing out of the backwash line.
Watch the sight glass or discharge water.
The water will usually start dirty or cloudy.
Backwash until the water clears.
This usually takes 1–3 minutes, depending on how dirty the filter is.
Do not walk away.
The pool water level can drop quickly during backwash.
Watch the pool water level.
Stop if the water gets close to the bottom of the skimmer opening.
Turn the pump off again.
The pump must be off before changing from BACKWASH to RINSE.
Press the multiport handle down.
Push fully down before rotating the handle.
Turn the multiport valve to RINSE.
Rinse settles the sand bed and clears dirty water from the valve.
Turn the pump on.
Let the pump run on RINSE.
Rinse for 20–30 seconds.
Run until the sight glass or discharge water looks clear.
Turn the pump off again.
Do this before returning the multiport valve to FILTER.
Press the multiport handle down.
Again, push down fully before turning.
Turn the multiport valve to FILTER.
This returns the system to normal filtering mode.
Confirm the 3-way valve is at #4.
Normal operation is 50/50: half skimmer and half bottom drain.
Turn the pump on.
The system should now be filtering normally.
Check the return jets.
Make sure clean water is returning to the pool with normal flow.
Check the filter pressure again.
The pressure should be lower than before the backwash.
Put away the backwash hose.
Let the hose drain before rolling it up to avoid making a mess.
Record the clean pressure.
Write down the new clean PSI so the next backwash is easy to judge.