Bradford White SDW2504T*FBN, Service Manual Supplement

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This section is intended to provide a better understanding of the solar thermal design
application and how it varies from the base model listed on page 3.
Solar Thermistor Wiring
The solar with gas backup water heater comes provided with two sets of twisted
thermistor wiring. They are color coded for ease of use.
The solar with gas backup models come with an internal double-wall heat exchanger.
Brown thermistor wiring is provided under an access panel between the solar heat
exchanger connections. A thermistor (not included) wired to this pair can be
connected to the solar control to determine the temperature differential between the
tank and the solar collector. The control can then activate a circulator to heat the tank.
To assist in connecting the thermistor, the end has a supplied wire nut. A bracket and
plate is supplied to mechanically press the thermistor against the tank wall.
A twisted orange wire set is provided under the upper access panel. Some solar
controllers have locations for a second tank temperature input. This is not used for
controlling the solar thermal system, but helps the end user understand what an
anticipated delivered temperature may be.
EcoStor2™ Solar Thermistor Wiring
Brown and Orange twisted
thermistor wires
Upper Access Location
(Orange Twisted Pair)
Lower Access Location
(Brown Twisted Pair)
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