There are pool heaters that last for 20 years and some that don’t make it past five. Make sure that you trust your dealer and understand the product they are selling you before you purchase. Aquatherm is the largest US manufacturer of solar thermal heating systems. We install their systems because they are reliable with little to no maintenance needed and they are backed by a 12-year full repair and replace warranty. Most other solar pool heater companies only offer five-year warranties at max.