Can an external Rinnai Tankless Water Heater be used in cold climates?
Good news: The short answer is yes. Rinnai tankless water heaters feature freeze protection for outside temperatures as cold as -22° F (-30° C) for indoor models or as cold as -4° F (-20° C) for outdoor models when protected from direct wind exposure and as long as the appliance has both power and gas supply. The pipes feeding the unit must be heat-traced and insulated to provide the necessary freeze protection.
Rinnai strongly recommends the installation of an optional drain-down system on units installed outside in cold climates. Once installed, the system allows water inside the unit to drain out if there’s a power and/or gas outage or a component failure. See the owner’s manual for optional drain-down system piping.