Pump HP for heater

[seminolewind]

I have my 24' AG piped into my outdoor furnace that puts out 225k BTU per hour. My question is my pump is a Hayward 1 HP (something) Flo and the hot water out of the returns is wimpy compared to when I'm not pumping into the heater. Would a higher hp pump be better or is this normal?

[mas985]

A heater increases the head loss experienced in your plumbing which in turns reduces flow so this is normal. However, many pools are plumbed so that water is not redirected around the heater when not in use as yours is so they do not notice any difference. I would stick with the 1 HP pump to minimize your power bill and just run it longer when the heater is in line.