jgy2001 Posted June 23, 2020 Report Share Posted June 23, 2020 I have a 10 x 7 ft 2200 gallon water spa, one pump 2500 gph. I plan to install outdoor gas tankless heater 120,000 BTU @ 6 GPM. Can you tell me how long will it take me to heat up the spa increase in 1 F degree? Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted June 23, 2020 Report Share Posted June 23, 2020 https://poolchemicalcalculator.com/Pool-Heat-Time-Calculator.html 9 minutes according to the calculator. Your 2500gph pump will not meet the 6gpm flow rate. Not sure what effect that will have, or if the heater will operate at a lower flow rate. Also, that will be some seriously hot water returning to the spa which could be a problem for your pipes or anyone who touches the return flow while in the spa. Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted June 23, 2020 Report Share Posted June 23, 2020 Sorry, I was about to go to bed when I answered. Clearly, your flow will be sufficient. Ate you plumbing it on a bypass? Quote Link to comment Share on other sites More sharing options...
jgy2001 Posted June 23, 2020 Author Report Share Posted June 23, 2020 2500 gph pump is 41 gpm flow rate, right? That is more than the mininum required for this gas tankless heater, right? Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted June 23, 2020 Report Share Posted June 23, 2020 Yes. As I said, it was late and I was tired and I did not properly calculate the flow rate. Your pump is more than sufficient. I would plumb it on a valved bypass so you can dial in the flow to the optimal rate. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.