Using Available Led Indicators - Aprilaire 8555 Owner's Manual

110-793B 7/11/01 3:29 PM Page 31
Using The Available LED Indicators
This model is equipped with 3 LED indicator lights. These LEDs are located along the top edge of
the thermostat panel (not on the display) and look like small, clear edges protruding out of the top of the
thermostat. The center LED is factory wired and will glow red when the backup heat source is being
used. When the left and/or right LED is supplied with a 24 VAC signal, the LEDs glow red and can be used
to indicate many other system functions such as when the humidifier or fresh air exchanger is running.
Contact your installing contractor to understand what the left and/or right LEDs signal.
Use of left and right LEDs will require equipment and additional wiring at the thermostat which should
only be done by a qualified heating and cooling contractor.
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