Replacing My RayPak 406 Propane Heater

Maryland Dan

New member
Aug 14, 2014
Pasadena, MD
I have a 25k gallon pool with attached spa (approx. 5k gallons). I only use the propane heater for the spa but everything is plumbed through the same pump so the original heater was sized to heat the entire pool. The system is 15 years old and the heat exchanger began leaking last summer. I plumbed around the heater and we survived the season without a hot tub.

My first thought was to downsize the new heater to save money since its only used for the spa, but the posts I've read here seem to indicate that the propane cost should be the deciding factor. Cost difference between the 406k BTU and 206k BTU heaters is just over $500. I've read here that they use the same amount of propane. So the higher BTU heater will get the spa up to temperature faster, thereby using less propane and making up for the extra $500 in the long run. Does everyone agree?

Should I look at any products other than RayPak? I've had many issues with sensors and thermostats on the old heater but I feel that's to be expected given its age. I have a new saltwater system and live with hard well water.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
You use the same amount of propane to generate a given amount of heat.

A smaller heater will run longer and use less propane over a greater amount of time. That will be the same as the propane used by a larger heater that runs for less time.

The extra cost of the larger heater gives you faster heat time and no significant savings in propane used.

Raypak heater is about as good as it gets. Heaters live in a harsh environment. Use them often and give them some preventative maintenance along the way and you ill get a good life form them.