A malfunctioning backwash valve should be repaired promptly because it can create major headaches for your pool.  In this section we talk about the most common problems with backwash valves and some solutions to those problems.

POOL LOSING WATER

 

• If your pool suddenly starts losing water, you may have a leaky backwash valve. Sometimes the backwash line terminates close to to the equipment area so you can go look at the end of the pipe and see if it is dripping or pouring water.

Often (if the pool is built to code) the backwash line terminates in a p-trap that dumps into a sewer cleanout. It is a little hard to detect leakage here, but if you can hear water running into the cleanout long after the pool has been backwashed, then you probably have a leaky backwash valve.

The best solution is to take the backwash valve apart and physically inspect the seals and gaskets and replace as needed.

BACKWASH VALVE LEAKING

 

• Sometimes the valve itself is leaking water. There are several points from which a backwash valve can leak.

Leaking Stem – if the valve is leaking along the shaft of the valve, take a good hard look at the valve shaft.

If the shaft appears to be OK, then the small shaft o-ring can be replaced, but that is no small task. (The hardest part is getting the valve handle off.)

If the shaft is corroded or rough. then you need to replace the entire internal assembly, but more importantly, figure out how the shaft got so corroded in the first place. Perhaps it was just bad water chemistry, but if your water chemistry has been fine, then you need to look at the chlorinator, or more importantly, the check valve before the chlorinator.

Chlorine tablets are very corrosive (pH of 2.3 or so) and if there is not a good working check valve in place before the chlorinator, it can allow that acidic chlorinated water to seep back into the other parts of the pool equipment when the pump is off.

Leaking Valve Body – if there is a crack anywhere in the valve, then the entire valve needs to be replaced.