Polaris PB4 booster loud with low pressure

[pool2628]

Hi TFP; I am new owner of ~20k pool with hayward main pump and a polaris cleaner w/pb4 booster. The Polaris booster was working fine the other day, the cleaner moving quickly about the bottom of the pool. However, when I turned it on today it was noisy and the cleaner did not have much pressure, moved really slow. The pool is spotless, nor cal summer, and I am wondering what may have happened to the polaris booster. There are two timers, one for main and one for booster, and I am thinking the booster may have been running without the main pump on. As a result, this may have burned up the booster? Not sure, hoping someone can guide me a little as what to look for on this pb4 booster. Many thanks!

 

[Bama Rambler]

Welcome to TFP.

The most common noise makers in motors are the bearings. More rare is the impeller coming lose on the shaft. Take the back cover off the motor and tuen it by hand and see what it feels like. If it's rough and grindy (is that even a word) sounding it's probably the bearings.