Spa Heat Time


New member
Dec 7, 2019
Charlotte, NC
New pool owner here. Inground pool/spa. I have a spa that's about 937 gallons (7' x7'). My pool/spa heater is a Raypak (399,000 mbtuh). I started the heater for the first time and it took 2 hours to raise it 51 degrees (started at 49 degrees). The air temp was only 58. Should it take that long?


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Welcome to the forum!!

With appropriate inefficiencies, I am showing 1 hour and 49 minutes to heat your water. So, pretty close.

I have an old spreadsheet I use. Let me see if I can find it on the forum already.