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FLOW
• This water heater comes equipped with heating blocks to protect it against damage associated with 
freezing.
• For this freeze protection system to operate, there has to be electrical power to the water heater.  
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 freeze protection thermostat senses temperatures 
at 36.5 °F (2.5 °C) or lower.
• For the 140 Indoor (T-H3M-DV) model:
• In any areas subject to freezing temperatures, the manufacturer highly recommends an indoor 
installation with an indoor 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.
• The manufacturer also highly recommends the use of a backflow preventer (sold separately)
       to minimize the amount of cold air entering through the exhaust venting when the water
       heater is off.
• It is the installer’s responsibility to be aware of freezing issues and take all preventative measures.  The 
manufacturer will not be responsible for any damage to the heat exchanger as a result of freezing.
• If you will not be using your heater for a long period of time:
 1.   Completely drain the water out of the water heater. Refer to p. 41.
 2.   Disconnect power to your heater.
  This will keep your water heater from freezing and being damaged.
Only pipes within the water heater are protected by the freeze protection 
system. Any water pipes (hot or cold) located outside the water heater will not 
be protected. Properly protect and insulate these pipes from freezing.
CAUTION
FREEZE PROTECTION SYSTEM
Appliance/Use
Flowrate
GPM(US) L/min
Lavatory Faucet 1.0 3.8
Bath Tub 4.0 – 10.0 15.2 - 37.8
Shower 2.0 7.5
Kitchen Sink 1.5 5.6
Dishwasher 1.5 5.6
Washing machine 4.0 15.2
HouseholdFlowRates
Taken from UPC 2006
• The flow rate through the water heater is limited to 
a maximum of 7.0 GPM (26.5 L/min).
• The temperature setting, along with the supply 
temperature of the water will determine the flow 
rate output of the water heater.
• Please refer to the temperature vs. gallons per 
minute charts on p. 54 to determine the likely flow 
rates based on your local ground water temperature 
and your desired outlet water temperature.
• Refer to the table to the top right for typical
      household plumbing fixture flow rates to determine
     what the water heater can do in a household
     application.
• Based on the United States Department of Energy 
     method of testing water heater output, the water
     heater is rated for gallons per minute (GPM) (liters 
     per minute (L/min)) for Natural Gas and Propane, 
     when raising the water temperature by 77 °F
     (43 °C) (from 58 °F to 135 °F (14 °C to 57 °C)). 
     See the chart on the right.
Unit: GPM (L/min)
Model Flowrate
140 (T-H3M) 
Indoor
3.0 (11.2)
Outdoor
Normal Operaon
Owner's Guide