What angle should a solar panel pool heater be set at?

There are two angles to consider: North-South direction and inclination up from horizontal. For best performance, face the solar panel generally south at an inclination of 15 to 30 degrees up from horizontal. This will point the face of the panel nearly directly at the sun. Don't stess over the exact angle, you should be fine as long as its close. Hope this helps... In terms of angle, I have read that you should tilt the panel at an angle equal to your latitude geographically. So, LA is 34 degrees LAT, therefore tilt the panel 34 degress for year round installation. If possible it should be tilted accordingly for seasons. I found a web site with the acronym RSPEC (Reduce Swimming Pool Energy Costs) that suggests the following: The collectors should (ideally) face due south and should be angled based upon your latitude. For heating in the summer months subtract 10-15 degrees from your latitude. For heating in the winter months add 10-15 degrees to your latitude and for year round heating install at your latitude.