Every one of our boilers comes with a digital aquastat, flow sensor, air eliminator, and 50 gallon tank. We guarantee the best prices for an outdoor wood boiler, gasifier, parts, and accessories!! Our units are now over built to last many many years. Many safety features standard. We also feature new insulated tongue and groove doors that seal tight and prevent seal from falling off. Acrylic stucco comes standard on cement fiber board that covers our insulation but can have a number of options like log cabin, field stone, or slate. These units will never rust or build up creosote because we use a heat conducting refractory cement with millions of stainless steel needles in them that is cast over brazed copper heat sinks that surround entire unit. Units are very efficient and made to last for decades and cost much less than comparable steel units that will rust or welds break! Many happy customers! We also build true gasification boilers that can burn almost anything and never smoke. You can also hook up to pools and driveways to melt ice. These units are efficient! You can see the one inside our factory burning just saw dust on this link http://www.youtube.com/watch?v=CqtIoBzylMw&feature=related. Burns logs also along with stall waste, wood chips, pellets, corn, or coal. We have the biggest fire boxes around for gasification!! Call me anytime at 616-232-0373, 616-551-0176, or visit our website at heissheaters.com. We warranty our units to the fullest.