I recently added a heater to our pool/spa and was told my current pump would be fine to heat only the spa (which is all I plan on using in the winter anyway). When I shut the valves to/from the pool off and leave the valves to/from the spa open, the pump filter fills with air and eventually breaks the prime on the pump. I believe switching to a 2-speed or variable pump would solve my problem as I am effectively trying to use the same pump to filter a ~20,000 gallon pool/spa during the day and a ~550 gallon heated spa on occasion. Is that a reasonable assumption?
I currently have a Pentair Challenger high performance pump (CHII-N1-2A) mated to a Century B855 2.0HP/SF1.10 single speed pump.
Would the B2983 1.5HP/SF1.47 motor and "Toggle Switch and Canopy Kit for 56Y 2-Speed 2512558-001" be a suitable replacement set?