This is a very simple and powerful heater for just about any residential pool. I keep mine near 90 F when it is not hot outside.It is a high-quality straightforward design that is very potent at heating water very rapidly. It looks like great 1960s technology that is very easy to work on.I have now used it for over five years in Ohio almost nonstop. Unfortunately, service for them in areas like this with almost no heated pools is the replacement.Mine stopped working a month ago when I tested it. After trying to find someone that service them and had seen one before, I contacted their tech support and they understandably don't want consumers working on these high voltage devices. But you can buy all their parts online. Without instructionsI did ask them if there is a reset button and they told me "no it resets by turning the power on and off", so I ended up replacing the thrrmasstat and both elements. which a guy at their support did suggest "if I must".Still did not work so I went to replace the Hi-temp switch in it and found a very well hidden reset switch on it. I pushed it in turned on the power and it worked. It did not need any parts at all.My tiny 8'X12 X5' pool is solid year round and enclosed for winter use, I built it into my deck. The heater sits is an insulated cabinet on the side of the pool only about a foot from the surface, which means I had to adjust the preset dial on it for this lower pressure, but I went too far and before it overheated this hidden heat switch pooped.I ended up having Hayward recommend someone that acted was like a pro for these. He came out and said he had seen one before. After about an hour he determined that switch was bad. He had no clue it had a reset on it.The whole point is that the heater worked as designed, that switch pooped before anything was damaged. The heater is a great device, mine is about to start its 6th year.