Pump Seals For Pool Pumps

The pump seal, also known as the shaft seal is one of the most critical componemts of any pump.  It is also the most fragile.  It has often been compared to a toy balloon in terms of durability and warranty. A small pinhole can instantly destroy a large balloon.  It is also very easy to destroy or damage a pump seal and most pump and motor manufacturers will not warranty a pump or replacement motor if it shows any signs of water damage caused by seal failure. Water damage caused by seal failure is the most common reason cited by manufacturers for denial of warranty claims (and some of these motors are only  a few months old). Some say this is similar to the warranty you get on a balloon purchased at a party store.  Do not assume that just because the motor or pump is within the warranty time period that it will be replaced or repaired.  If you look carefully at the warranty paperwork fine print on many of the common motors and pumps you will find more loopholes than a slice of swiss cheese.  The best plan of action is to avoid trouble by  (1) Purchasing the best seal available for your application (2) Install it correctly (3) Maintain it by watching for failures.

Seal selection is very critical in swimming pool pump applications because pool water contains agressive chemicals such as chlorine, salt, ozone etc.  This combination is very detrimental to the pump seal.  The pump seal's job is the keep the pool water within the water pump housing (also called the WET END) and out of the electric motor.  Water and electric don't mix.  It is estimated that 75% of pool pumps fail prematurely because the motor is damaged by water intrusion due to  seal failure.  Seal failure is caused by many different reasons:

(1) When  the pump runs dry (motor running but water not flowing thru pump) the seal can get hot and crack and may also melt the seal plate and the pump will start leaking, this small leak after a period of time will work its way into the motor where the chlorinated water will eventually rust and destroy it.  A run dry condition can be caused by a variety of conditions such as (a) the pump basket strainer lid O'ring my be damaged or rotten causing air to be drawn into the pump (b) the plastic lid on the strainer basket may have a small crack causing air to get in --It only takes a pin hole in the suction side of the pump to cause seal failure (the same size hole that would destroy the balloon)  (c)  Debris clogging the intake such as leaves clogging an automatic pool cleaner, especially during the windy month of March. (d) FIlter clogged not allowing water to flow thru it

(2) Chemical Damage is another common cause of seal failure.  Excessive chlorination and shocking can damage the seal resulting in it leaking. Overchlorination caused by putting chlorine tablets in the skimmer or pump basket is another reason for seal failure

(3)  Pool Leaks:  If the pool leaks water, the pump can run dry resulting in seal leakage or
damage

(4) Normal Wear & Tear:     We find that most OEM seals fail and begin to leak after approximately 7500 operating hours on the average pool in Florida which is about (3) years of operation, So it is best to proactively replace your pump seal every 2 to 3 years.
Pools that have salt or ozone sanitation systems should have the  seal replaced with a high quality viton / carbon  seal on a more frequent basis, generally every 1 to 2 years

(5)Animal Damage:    We find many poolowners with suction side automatic cleaners experience seal failure due to the pump running dry caused by animals such as rats, possums, and racoons chewing the flexible hoses going to the cleaner... Some of the holes are as small as pinholes, so they are barely visable to the naked eye, but enough to cause loss of prime and subsequent seal failure, Just as  we said before, a pinhole can destroy a balloon, it  can also destroy your pump seal.

THE BOTTOM LINE

Any time there is leakage at the pump, the pump should be shut down and the seal and or seal plate replaced.  Running any pump that is leaking (even a small drip) will cause premature destruction of the motor.  There are many types and qualities of pump seals available for pool pump replacement and we recommend you purchase the highest quality seal from a major manufacturer and install it properly. Because of the fragile nature of pumps seals, it is best to watch for leaks and shut down the system if one is discovered.  Remember a properly operating pool pump should not leak or drip at all