MULTIPORT VALVE 101
There are three types of pool filters: cartridge, sand, and DE (diatomaceous earth). Sand and DE filters use a multiport valve to help clean or backwash the filter media. Multiport valves are called multiport valves because they have multiple ports inside the valve that allows the water to move in multiple directions. The most common multiport valves have a locking lever handle that can be turned to any one of seven settings: filter, waste, winter, closed, backwash, recirculate and rinse. By changing the position of the lever, you can route the water coming from the pump around or through your filter in different ways. This routing of the water allows you to perform various maintenance operations on your pool water.
THE SETTINGS
1/ FILTER. The FILTER position is the normal setting for your filter valve and will stay locked here the majority of the time. In this position, water is pushed into the filter tank, passes through the filter media, exits the tank, and returned back to the pool. Another common use of the FILTER setting is while vacuuming the pool.
2/ WASTE. The WASTE setting is one of two 'bypass' settings on a multiport valve. WASTE redirects the water pumped from the pool and sends it straight out of the backwash line or hose. There are two common instances you would use the WASTE setting. The first is to lower water levels. The second is when you need to vacuum debris and do not want the debris to pass through the filter media.
3/ WINTER. The WINTER position is the setting used when it is time to close the pool for the winter.
4/ CLOSED. The CLOSED position is rarely ever used and simply means that water cannot enter the valve.
5/ BACKWASH. The BACKWASH position is a setting that reverses the flow of water as it enters and exits the filter tank. The purpose of the BACKWASH setting is to clean the filter by flushing out the dirt and debris that has accumulated in the filter medium and send it out through the backwash line.
6/ RECIRCULATE. The RECIRCULATE position is the second 'bypass' setting on the multiport valve. Water is drawn in from the pump and then returned straight to the pool, bypassing the filter altogether. The best use of the RECIRCULATE setting is when there is a problem with the filter, and it cannot be used. Until the filter can be repaired or replaced this will at least keep your water circulating to prevent stagnation.
7/ RINSE. The RINSE position is a setting to be used after backwashing a sand filter. It will flush out and rinse the sand bed of remaining dust particles to prevent dust from blowing back into your pool. Water is flowing through the filter in the normal direction but is diverted to the backwash line. 15-20 seconds is all that is needed to rinse a sand filter bed.
Remember to always turn your pump OFF before turning the Multiport Valve. Changing positions while the pump is running can not only damage the valve but it can cause pressure to build inside the system causing a blowout. Nobody wants that.
/HAPPY SWIMMING/