Rinnai RSC199i Installation And Operation Manual page 21

4.3.5 Freeze Protection
Make sure that in case of freezing weather the water heater and its water lines are protected to
prevent freezing. Damage due to freezing is not covered by the warranty.
When connected to gas and 120-volt power supply, the water heater will not freeze when the outside
air temperature is as cold as -22°F (-30°C) for internal (indoor) models or -4°F (-20°C) for external
(outdoor) models, when protected from direct wind exposure. Because of the "wind-chill" effect, any
wind or circulation of the air on the water heater will reduce its ability to protect itself from freezing.
In the event of a power failure and/or gas interruption at temperatures below freezing, the water
heater should manually be drained of all water to prevent freezing damage. In addition, drain the
condensate trap, drain line and pressure relief valve.
Loss of freeze protection may result in water damage from a burst heat exchanger or water lines.
The water heater may be drained manually. However, it is highly recommended to install the optional
Drain Down Kit accessory that will enable the water heater to immediately drain upon loss of power
(the condensate trap and pressure relief valve are not affected by the Drain Down Kit and must be
manually drained).
The freeze protection features will not prevent the external piping and valves from freezing. It is
recommended that hot and cold water pipes be insulated. Pipe cover enclosures may be packed with
insulation for added freeze protection.
Rinnai Tankless Water Heater Installation and Operation Manual
Freeze Protection Piping Diagram
Freeze Protection Piping Diagram
Hot Water
Hot Water
Supply Line
Supply
1/2 in. Normally Open Solenoid Valve
Line 1/2 in. Normally Open Solenoid Valve
Route Drain Per Local Code
Route Drain Per Local Code
Figure 7: Freeze Protection Piping Diagram
Vacuum Breaker *
Vacuum Breaker
Legend
Vacuum Breaker
Vacuum Breaker
Pressure Relief Valve
Union
Pressure Relief Valve
Check Valve
Union
Ball Valve
Check Valve
Solenoid Valve
Ball Valve
Drain Valve
Solenoid Valve
Drain Valve
* Position vacuum breaker
above water heater.
3/4 in. Normally Closed Solenoid Valve
3/4 in. Normally Closed Solenoid Valve
Gas Supply
Cold Water
Cold Water Supply Line
Supply Line
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