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T8112C,D Electronic
Programmable Thermostats
INSTALLATION INSTRUCTIONS
Location
APPLICATION
Install the thermostat about 5 ft. (1.5m) above the floor in
an area with good air circulation at average temperature.
The T8112C,D thermostats provide electronic
programmable control for 24 to 30 Vac heating and
Do not install the thermostat where it can be affected by:
cooling systems.
— drafts, or dead spots behind doors and in corners.
— hot or cold air from ducts.
RECYCLING NOTICE
— radiant heat fro
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T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS 1. Remove mounting plate from the wall, and drill IMPORTANT 3/16 inch holes in wall (if drywall) as marked. For When using a high efficiency furnace such as a firmer material such as plaster or wood, drill 90 percent or greater AFUE (Average Fuel 7/32 inch holes. Gently tap anchors (provided) into Utilization Efficiency) unit, adjust screw A out drilled holes until flush with the wall. one turn and screw B in. 2. Reposition mounting plate over holes,
Summary of the content on the page No. 3
T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS 5-WIRE HEAT/COOL (JUMPER REMOVED) 2-WIRE HEAT-ONLY (JUMPER INTACT) A C A C B D B D JUMPER W Y G W Y G R Rc R Rc HEATING HEATING FAN RELAY OR RELAY OR RELAY VALVE COIL VALVE COIL L1 (HOT) 1 L2 COOLING CONTACTOR 1 1 COIL 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M1709B L1 L1 (HOT) (HOT) L2 L2 Fig. 4. Typical hookup in two wire lead only (jump
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T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS T8112C JUMPER (FACTORY- INSTALLED) REMOVE INSERT IF 5-WIRE SYSTEM STRAIGHT 5/16 in. A. ENGAGE TABS AT TOP OF B. PRESS LOWER EDGE UNDER (8 mm) THERMOSTAT AND MOUNTING PLATE. OF CASE TO LATCH. SCREW HEAD STRIP AM TU LEAVE END OF WIRE VISIBLE HERE M1712A Fig. 8. Proper wiring technique. M5780 T8112D A. ENGAGE TABS AT TOP OF B. PRESS LOWER EDGE THERMOSTAT AND MOUNTING PLATE. OF CASE TO LATCH. M3002A Fig. 9. Holding therm
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T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS As the batteries are running low, a “bAt Lo” indicator flash Installing Batteries for one to two months before batteries run out completely. Replace the batteries as soon as possible after the IMPORTANT indicator starts flashing. If the batteries are not replaced Batteries must be installed for programming and sometime during the flashing “bAt Lo,” the indicator operation of the thermostat and heating/cooling eventually stops flashing. “bAt Lo” will s
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T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS Fan CHECKOUT Move the thermostat system switch to OFF and the fan switch to ON. The fan should run continuously. With the Heating system switch still in the OFF position, move the fan Do not check heating system operation by jumpering switch to AUTO; the fan should stop. thermostat terminals at the primary control such as the gas valve, zone valve, or oil burner control This will Move the system switch to HEAT and the fan switch damage the thermostat.
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T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS TROUBLESHOOTING GUIDE If… Then… Display will not come on. • Set the system switch to OFF. Remove batteries. Insert batteries backward for at least five seconds to reset thermostat. Correctly replace batteries. Display should come on. • Make sure batteries are fresh and installed correctly. • Gently clean battery contacts using a soft pencil eraser. Do not use anything abrasive on the clips. Temperature display will not go lower • The temperature setti
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T8112C,D ELECTRONIC PROGRAMMABLE THERMOSTATS Home and Building Control Home and Building Control Honeywell Inc. Honeywell Limited-Honeywell Limitée Honeywell Plaza 155 Gordon Baker Road P.O. Box 524 North York, Ontario Minneapolis, MN 55408-0524 M2H 3N7 69-0917—2 69-0917—2 G.H. Rev. 4-98 Printed in Mexico www.honeywell.com 8
