Manual

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FLOW
• The flow rate through the FLASH T-K3-OS/SP is limited to a maximum of 7.0 GPM.
• The temperature setting, along with the supply temperature of the water will determine the flow
rate output of the unit.
• Please refer to the temperature vs. gallons per minute chart on p. 38 to determine the likely flow
rates based on your local ground water temperature and your desired outlet water temperature
combination.
• Based on the United States Department of
Energy method of testing water heater output,
the T-K3-OS/SP is rated for 246(OS)/240(SP)
gallons per hour (GPH) or 4.1(OS)/4.0(SP)
gallons per minute (GPM) for Natural Gas, and
252(OS)/246(SP) GPH or 4.2(OS)/4.1(SP)
GPM for Liquid Propane, when raising the
water temperature by 77°F (from 58°F to
135°F).
• Refer to the chart to the right for typical
household plumbing fixture flow rates to
determine what the FLASH T-K3-OS/SP can do in a
household application.
FREEZE PROTECTION SYSTEM
• This unit comes equipped with heating blocks to protect it against damages associated with
freezing.
• For this freeze protection system to operate, there has to be electrical power to the unit. Damage
to the heat exchanger caused by freezing temperatures due to power loss is not covered under
the warranty. In cases where power losses can occur, consider the use of a backup power
supply.
• The freeze protection system will activate when the surrounding and/or outside temperatures
drop below 36.5°F (2.5°C).
• In any areas subject to freezing temperatures, Takagi highly recommends installing the unit
indoors (only T-K3-SP model). In such an installation, freezing issues can only occur if cold air
enters through the venting into the heat exchanger, whether by negative pressures within the
installation location or by strong outside winds. It is the installer’s responsibility to be aware of
these issues and take all preventative measures. Takagi will not be responsible for any damage
to the heat exchanger as a result of freezing.
• Takagi also highly recommends the use of a back flow vent damper for the T-K3-SP to minimize
the amount of cold air entering through the exhaust venting when the water heater is off.
• If you will not be using your heater for a long period of time:
CAUTION: Only pipes within the water heater are protected by the freeze protection
system. Any water pipes (hot or cold) located outside the unit will not be protected.
Properly protect and insulate these pipes from freezing.
Household Flow Rates
Appliance / Use
Flow Rate (GPM)
Lavatory Faucet 1.0
Bath Tub 4.0 – 10.0
Shower 2.0
Kitchen Sink 1.5
Dishwasher 1.5
Washing Machine 4.0
Taken from UPC 2006
1. Completely drain the unit of water. Refer to p.24.
2. Disconnected power to your heater.
This will keep your unit from freezing and being damaged.