I have a Sta-Rite Dura-Glas pump with a 3/4hp uprated motor. The motor is realtively new. All the seals have been replaced on the pump.
On starting the motor, the only way I can get the pump to pull water is to move a valve to the drain the pool pipe. Once it gets a good enough flow going, I switch the valve to send the water through the filters. The pump then has a good flow of water. But slowly, like a few minutes, the flow of water gets slower and slower, until the pump runs dry. The motor and pump had worked normally prior to this happening.
The filters are clean. I’ve even tried it without the filter cratridges in place. There’s a checkvalve at the bottom of the filter tank that seems to be working. The pump is probably 25+ years old. It came with the house when I bought it 23 years ago. I don’t know exactly how the system was designed. There’s a spa with a fountain that drains into the pool.
I’m totally confused as to what the problem might be. Is it a pump problem or something else in the system? The impeller looks OK. It’s never been replaced.
Thanks
