Attempts to acquire a Bosch AquaStar Tankless Hot Water Heater Manual led me to www.boschappliances.com. There was no listing for Hot Water Heaters. A note to Contact Us' returned the phone number 800-944-2904, which when contacted was not the right department and was given #800-692-6724, then # 866-442-6724, and then # 800-642-3199, where I was instructed to visit www.boschhotwater.com... Which Internet Explorer was unable to access. Talk about user/consumer unfriendly. A total run-around. I won't be buying Bosch again.