The Solahart unit is the best solar hot water heater in the world! You can't find a better or simpler unit. The installation and customer service are the pits! We ordered ours in July and it took until October to get it installed and that was after the install was interrupted for some "emergency." I had to refile the paperwork with Unisource as the originals has expired due to the delays. Today we discovered the back up booster was not wired in properly and my wife got shocked when she touched the diverter spout in the bath tub. Unfortunately they are closed for the long Thanksgiving Day weekend so we have no clue as to when this dangerous mistake can be corrected.