Rinnai RC80HPI - Manual (Page 22)

22 Manual - Rinnai Condensing Water Heaters
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.
To manually drain the water:
1. Shut off cold water supply and gas supply.
2. Turn off the temperature controller.
3. Disconnect the power to the water heater.
4. Open hot water tap or open hot water drain plug at the
hot water outlet.
5. Remove water filter to drain the cold water.
6. Unscrew the water drain plug from the drain line next
to the hot water outlet.
7. Remove the condensate trap drain plug and allow to
drain.
Freeze Protection Piping
Manual draining of the water heater
WARNING 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.
To resume normal operation:
1. Confirm that all water drain plugs are removed, that the
gas supply is turned off, and that all taps are closed.
2. Insert the condensate trap drain plug.
3. Screw in the water drain plugs.
4. Screw in the water filter in the cold water inlet.
5. Open the cold water supply.
6. Open a tap and confirm that water flows, and then
close.
7. Turn on the power.
8. After confirming that the temperature controller is off,
turn on the gas supply.
9. Turn on the temperature controller.
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
MSA or EZConnect should be drained to prevent freezing if not in
use.)
1. Turn the water heater off.
2. Close the gas supply valve.
3. Reduce the flow to about 0.1 gal/min or to 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.
HOT
COLD
ON!
0.1 gal/min or
about 0.2 inch
thick
Water
drain
plug
Water
filter
Condensate
trap drain plug
Hot water
outlet Hot water
drain plug*
Cold water
inlet
* Use a wrench or other
tool to unscrew the hot
water drain plug.