State 520 - Manual (Page 38)

Normal Operation
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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
Taken from UPC 2006
FLOW
 The flow rate through the water heater is limited to a maximum of 9.0 GPM for the 520 (T‐H2)
models, and 8.0 GPM for the 320 (T‐H2S) models.
 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. 50 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 520 (T‐H2)
models is rated for 282 gallons per hour (GPH) or 4.8
gallons per minute (GPM) for Natural Gas, and the 320
(T‐H2S) models is rated for 255 gallons per hour (GPH) or
4.3 gallons per minute (GPM) for Natural Gas, 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 water
heater 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, the manufacturer highly recommends an indoor
installation with the Direct Vent Indoor models. 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. The manufacturer will not be responsible for any
damage to the heat exchanger as a result of freezing.
 The manufacturer also highly recommends the use of a back flow vent damper 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:
1. Completely drain the unit of water. Refer to p. 39.
2. Disconnect power to your heater.
This will keep your unit from freezing and being damaged.
Appliance / Use Flow Rate (GPM)
Lavatory Faucet 1.0
Bath Tub 4.0 – 10.0
Shower 2.0
Kitchen Silk 1.5
Dishwasher 1.5
Washing machine 4.0
CAUTION