Rinnai REU-VA1320WF-US Operation And Installation Manual page 41

WARNING
If the water heater is not going to be used during a period of
possible freezing weather, it is recommended that the water
To manually drain the water:
1. Disconnect electrical power to the water heater.
2. CLOSE the cold water supply valve. Leave the hot water
valve and a hot water fixture OPEN to remove pressure
from the system.
3. Connect one end of a hose to the drain valve on the tank
and direct the other end to a drain. OPEN the drain
valve.
4. Allow the tank to drain.
5. Remove the hot water outlet(3/4" NPT) flex fitting from
the assembly. (Note: The tankless engine will still contain
approximately 1/2 gallon of water. Prepare a bucket to
catch this water.)
To resume normal operation:
Connect the hot water outlet(3/4" NPT) flex fitting to the
assembly.
Remove drain hose from tank and close drain valve.
OPEN the cold water supply valve to allow unit to fill.
Ensure hot water valve is OPEN.
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.
1. Turn the water heater off.
2. Close the gas supply valve.
3. Turn on a hot water tap to flow water about 0.1 gal/min or where
the stream is about 0.2 inches 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 off the power.
3. Wait until the water thaws. Check by opening the water supply valve.
4. Check the water heater and the piping for leaks.
Manual Draining of the Water Heater
To avoid burns, wait until the equipment cools down before draining the water. The
water in the appliance will remain hot after it is turned off.
DRAIN
HOSE
3/4' NPT Hot
Water Outlet
Flex Fitting
DRAIN
VALVE
RH180 Manual
HOT
WATER
VALVE
ON!
COLD
0.1 gal/min or
about 0.2 inch
thick
HOT
COLD
WATER
SUPPLY
VALVE
41