According to the manual of my AWB ThermoMaster 2HR 28.02WT Condensing boiler, it is compatible with a pre-heating solar system for tap-water only. It even has extra facilities to ensure that the ...
Possible Duplicate: How can I efficiently heat a pool? I have an in-ground pool at around 20,000 gallons and I live in the northeast (Maine). My pool gets direct sunlight for about half ...