I just bought a house with an inground pool and attached spa. I'm curious how quickly the heater *should* heat up the spa. Its not small, but it's not huge either. Just a good size. I have a Hayward H400 heater. This morning, I attempted to heat up the spa, and it went from 71 to 75 in maybe 30-40 minutes. That seems awfully long for a 400k BTU heater. What do you all think?
Thanks much in advance!