Do I Need New Pump?
We opened our pool this week, and are experiencing problems with our pool pump. We have an inground 16x32 rectangle pool, with depths ranging from 4 ft to 8 ft. The pump is an AO Smith 1 hp pump (the label says 110/220 V, max load 15/7.5 amps) connected to a Hayward sand-type filter. The pump is connected to a 15-amp circuit breaker, located right next to the pump outside, which is in turn connected to a 20 amp breaker inside the house.
Here's the problem: when turning on the pump via the breaker switch outside, the pump will turn on and prime fine for a while, but then it will trip the switch within about 20-30 minutes. It never trips it right away - sometimes it trips within 5 minutes, but usually within the 20-30 minute range. The weird thing is, like this morning, it will go on for hours until it trips. But so far this year, it trips eventually. Last year I remember we had intermittently a similar problem, although never this frequent - it would run fine for days. The pump is almost brand new - a pool technician installed it end of last year because apparently we didn't have a GFI (we bought this house recently) and whenever there was a thunderstorm the pump would surge and seize right up. We now have a GFI.
The pressure gauge on my filter is currently reading 12 psi - when I turned it on early this morning it read 8 psi, so it seems to be steadily increasing - which may be normal. I don't know what the typical psi should be - this is the first year we are maintaining the pool ourselves, we had a pool guy do it last year.
Additional info: I backwashed and rinsed the filter twice. The pump feels quite warm to the touch - not too hot to touch for a moment, but definitely painful if I keep my hand there for longer than 5 seconds.
Before turning on the pump this morning I cleared around the pool pump some shrub and bushes that were close to it, just to give it more ventilation - perhaps it's overheating and shutting itself off? Is that why it's running ok now?
Anyway - I'm lost why this happens. Any advice would be helpful - thank you!