Pool Heater Replacement - Old Jandy Lite2


Jun 5, 2016
Ontario, Canada
Good morning all,

So first off i'm a pure chlorine pool guy and the Boy is getting a bit older and likely will be using the pool more. Anyhow, I have slowly been upgrading the pool equipment I have and I think that I need to replace the pool heater.

Key points:
- Existing pool heater installed 2006 - it is 250k BTU. Believe it already has a 3/4" natural gas line.
- Currently pool is 22k gallons vinyl in-ground with shallow/deep end /w 2 returns and 1 skimmer. Appears to all be 2".
- Unit works OK but not certain how efficient it is. All burners seem to light. It is very rarely used due to my phobia of a $600 gas bill LOL.
- Lots of pine trees near deep end. Have a diving board which makes the use of a solar cover reel somewhat challenging.
- Wife is quite vocal and against a solar cover due to the added debris that gets in due to the pine trees and difficulty keeping the cover clean (the other end of the pool is shallow and has walk-in steps so not appropriate there).
- Likely would ONLY be utilizing the heater to supplementary increase pool temps prior to a swim during weekends.
- Regularly test the pool water and chemical levels are quite consistent.
- In-line chlorinator for pucks that has a check valve but only use it during system startup to help raise the Cya.
- Not impressed with the quality of my Hayward pool filter I replaced around 2 years ago. Never interested in adding any additional Hayward equipment moving forward.
- Concerned about a pool shop installing the unity incorrectly (have had to repair/correct installation deficiencies before). I would hire a local HVAC contractor and licensed gas fitter to connect the unit whom I highly trust and has done good work for me thus far.

- I'm between the point whereby I could run my present heater "into the ground" until there is a catastrophic failure and then temporarily plumb it out until I replace it or be pro-active, replace it with an easier to use model and plumb in a formal "bypass" (all pool water runs through the unit now). I'm also not 100% comfortable leaving it unattended in case something happens to it.
- Like the Raypak 406 based on the positive feedback and seemingly simple design of the unit. Heating BTU would increase from 250k-400k.
- Local pool vendor claimed that the 406 is way too big for any residential pool (said same thing about my sand filter but did that anyhow LOL and pool has never been cleaner).
- Does the Raypak 406/407 low NOx make sense or is it "too big" per the pool store?
- If it is too big, other recommendations (Pentair/smaller Raypak?)
- What type of ignition for the heater would you recommend?



LifeTime Supporter
Jun 23, 2011
I've got a 20+ year old 300k BTU natural gas heater. I contacted Pentair tech support and they suggested that it would be around 75% efficient. Modern heaters are about 85% efficient. I figured I might spend, at the most, $500 on gas in a season. So if I save $60 per season, it'll take 30 years for a heater to pay for itself. Note that we most often just use the pool on the weekends, and only turn the heater on when we plan to use it.

I don't think there's such a thing as "too big" as long as your flow rate is high enough to run the heater. Frankly, I was looking at 400k heaters for my 18000 gallon pool. I figured the larger heater would heat a lot faster, at least 50% faster, which would mean I don't have to run the heater overnight as much, which would lead to even more efficiency.