What size heater for 16 X 40 28,000gal in ground vinyl
Hi Barbara,
We normally suggest a heater that can give you a temperature raise of 1.5 degrees per hour. Your pool is roughly 640 Sq. Ft. so this would be a 266,000 BTU heater. If you went up to the larger 406,000 BTU heater then you would get a 2 degree temperature rise per hour.
I personally like the Raypak Heaters Listed Here
One thing you do want to consider is your gas line as the larger 406,000 BTU heater needs a larger gas line. Below is a chart to determine what size gas line you need for each BTU size.
Also if you are interested in seeing the temperature rise for various BTU sizes on your pool then you can refer to the chart below.
Thank You
Patrick