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5.0 Operation
5.1 Important terms explained
DHW Tank
SetPoint
Temperature the end user gets from the faucet. Recommend no higher than 140°F to
prevent scalding.
Tank Diff'l
Temp
The variance the control allows in the DHW Tank Set Point. A tank differential of 10°F is
recommended.
Maximum
Supply Temp
Highest DHW supply set point temperature the boiler will allow. Should be at least 30°F
higher than the DHW supply set point temperature.
Supply Diff'l
Temp
The variance the control allows in the DHW Supply Set Point. Trial setting of 20°F. Set
higher to reduce short-cycling around the DHW Supply Set Point.
5.2 Start-up
After the water heater has been plumbed and wired, and the boiler water piping is purged of air, the water
heater is ready to be started. Follow the boiler installation and operating instructions to place the boiler in
operation.
5.3 Temperature adjustment
The tank sensor controls the maximum water temperature in the water heater. If it is set too high, the resulting
hot water can cause painful scalding with possible serious and permanent injury. The temperature at which
this occurs varies with a person’s age, and the length of time in contact with the hot water. The slower
response time of infants, older, or handicapped people increases the hazard for them.
Check the water temperature at a hot water faucet
soon after the tank thermostat has satisfied, and the
circulator and the boiler have turned off. Adjust as
needed.
Lowering the thermostat setting will not have an
immediate effect on the water temperature because
stored water is used and because the thermostat
goes through the cycle of heating cold water and
satisfying at the new, lower temperature. Additional
temperature checks should follow the completion of a
heating cycle. Further adjustments may be required
after you have used the water heater.
Summary of Contents for IWT 119
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