Aprilaire 8533 - Manual (Page 12)

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Optional Feature – Locking The Keypad
If tampering with the thermostat is expected and unwanted, the keypad can be locked by changing the
position of the Keypad Lock DIP switch (switch no. 2) from the factory set OFF position to ON.
The DIP switches are located inside the thermostat on the circuit board. To access the DIP switches,
refer to the Installation Instructions that came with the thermostat, or consult your contractor.
In the locked position, only the following functions can be done:
• The outdoor temperature button will display the outdoor temperature.
• The thermostat will default to the Day setting.
• The DECREASE button and INCREASE button will temporarily change the Day setting
a maximum of ±6°F (±3° for Model 8533) for a period of 3 hours before the thermostat
automatically returns to the Day setting.
If the thermostat does not respond when a button is pushed, it may be because the keypad has been
locked. A Lock “ “ icon will appear when a button other than Outdoor is pushed if the keypad has
been locked.
110-964B 7/12/01 9:14 AM Page 12