Toyotomi FB-38N, Operation And Maintenance Instructions, Page: 30 / 41

11
WATER INJECTION AND AIR RELEASE FROM WATER HEATER PIPING
(FOR SEMI-CLOSED CIRCUIT PIPING)
SEMI-CLOSED CIRCUIT PIPING EXAMPLE
1. Antifreeze Solution specified by dealer should be used, and the density should be at a ratio
of 40% to 50%, as shown in the table.
Table of Antifreeze Solution composition ratio
Freezing temp. Antifreeze Solution City water
-10°C 40% 60%
-20° 50% 50%
NOTE: The rust proofing capability will be reduced if a Solution with a ratio less than 40% is
used.
[Calculation formula for required amount of Antifreeze Solution]
Requried amount of Antifreeze Solution (lit.) = {(Heat Exhanger capacity of Water Heater) +
(retained water volume in radiator) + (retained
water volume in piping)} x Antifreeze Solution
ratio (%) x 0.01
2. Inject the Antifreeze Solution as per article 1 into the Expansion Tank, and start Circulation
Pump to release air from each circuit on the Water Heater line.
3. If the water level of Expansion Tank goes down, inject circulation water mixed with
Antifreeze Solution until the water level does not go down.