I bought a Pentair Superflo 2-speed pump to replace a very old, single-speed that wouldn't run on seasonal startup. I got it from Amazon and I didn't realize, until after installation, that it didn't come with the unionized fittings. I connected it by using threaded PVC. It had a small leak at both the out joints from the pump and into the multi-valve, so I re-did them. There is still a small leak on the around the PVC fitting coming out of the pump. I don't know if by using the unionized fitting the leak will stop.
I have an issue that may be related to the leak but I'm not sure. One morning, I discovered that although the pump was still running, there was no water movement. The pump was on low speed. I re-primed and it ran without incident until today. I switched to high speed for several hours during maintenance. Afterward, when I switched back to low speed, the filter basket evacuated of water. It appeared to go "upstream" toward the pool. When this happened, the pump lost prime and failed to circulate water. I went back to high speed and it self-primed.
I like this pump despite this issue. The low speed is very quiet and move a substatial amount of water. Any advice is appreciated.