Installation Sheet

Rinnai Tankless Water Heater Installaon and Operaon Manual 67
If the water heater is not going to be used during a period of possible freezing weather, it is recommended that
the water inside the water heater be drained.
Running a low volume of water through the water heater to prevent freezing:
If the temperature exceeds the ability of the water heater to freeze protect itself, or if
power is lost, the following steps may prevent the water heater and external piping
from freezing. Units connected with EZ Connect (2-unit link) should be drained to
prevent freezing if not in use.
1. Turn the water heater o.
2. Close the gas supply valve.
3. Turn on a hot water tap to ow water about 0.1 gal/min (0.4 L/min) or where the stream is about
0.2 in. (5 mm) thick.
When the water heater or external piping has frozen:
1. Do not operate the water heater if it or the external piping is frozen.
2. Close the gas and water valves and turn o the power.
3. Wait unl the water thaws. Check by opening the water supply valve.
4. Check the water heater and the piping for leaks.
HOT
COLD
ON!
To avoid burns, wait unl the equipment cools down before draining the water. The
water in the appliance will remain hot aer it is turned o.
WARNING
To manually drain the water:
1. Shut o cold water supply and gas supply.
2. Turn o the temperature controller.
3. Disconnect the power to the water heater.
4. Close the hot and cold isolaon valves.
5. Open the pressure relief valve (PRV) lever.
6. Open the hot and cold drain valves.
7. Remove the condensate trap drain plug and
allow to drain.
8. Remove the pump drain plug (only for pump
version).
Piping Diagram
To resume normal operaon:
1. Conrm that the gas supply is turned o, all taps
are closed and PRV lever is closed.
2. Insert the condensate trap drain plug.
3. Close the hot and cold drain valves.
4. Open the cold and hot water isolaon valves.
5. Open a tap and conrm that water ows, and then close.
6. Connect power to the water heater.
7. Aer conrming that the temperature controller is o, turn on the gas supply.
8. Turn on the temperature controller.
5.4 Draining the Water Heater
HOT
COLD
PRV
CONDENSATE
HOT ISOLATION VALVE
PRV LEVER
COLD ISOLATION VALVE
CONDENSATE TRAP DRAIN PLUG
HOT DRAIN
VALVE
COLD DRAIN
VALVE
5.4 Draining the Water Heater