Honeywell T8131A Owner's Manual - Page 7

Remove Old Thermostat ³ Test to make certain that your heating and cooling systems are working properly. If either does not work, contact your local heating/air conditioning dealer. To avoid compressor damage, do not operate the cooling system when outdoor temperature is below 50°F (10°C). ᕢ Turn off power to the system at the furnace, or at the fuse/circuit breaker panel. ᕣ Carefully unpack your new thermostat and mounting plate; save the package of screws, the instructions and the receipt. ᕤ Remove the cover from the old thermostat. If it does not snap off when pulled firmly from the bottom, check for a screw used to lock on the cover. 7 ᕥ Loosen screws holding thermostat to subbase, wallplate or wall, and lift away. ᕦ Disconnect wires from old thermostat or subbase. As you disconnect each wire, use masking tape to label it with the old terminal designation. If there are only two wires, they do not require labeling. If there is an extra wire that is not connected to your old thermostat, you also will not be connecting it to your new thermostat. Keep the wires from falling back into the wall by wrapping them around a pencil as shown. WIRES THROUGH WALL OPENING M5136 69-0887-1