Honeywell T8112D Owner's Manual

About Honeywell T8112D Owner's Manual

The T8112D Programmable Thermostat provides energy savings for single-stage heating and cooling applications while providing reliable, precise temperature control.

FEATURES Honeywell T8112D

  • HEAT-OFF-COOL System switch.
  • AUTO-ON Fan switch.
  • Separate programs for weekdays and weekends (5 day/2 day).
  • Digital LCD display.
  • Easy to program and install.
  • Precise temperature control.
  • Four daily energy saving programs.
  • Compatible with most 24 Vac standing pilot, gas electronic ignition, oil or central electric systems.
  • Requires two AA alkaline batteries.
  • LCD flashes bAt Lo indicating low battery power.
  • Isolated heating/cooling circuits.


The specifications given in this publication do not include normal manufacturing tolerances; therefore, an individual unit might not exactly match the listed specifications. Also, this product is tested and calibrated under closely controlled conditions, and some minor differences in performance can be expected if those conditions are changed.

T8112D Thermostat: Provides electronic programmable control for 24 to 30 Vac heating and cooling systems.

Programming Keys:
Eight program keys.

Electrical Rating:
Battery operated (2 AA alkaline batteries).

System and Fan Ratings:
1.2A run; 7.5A inrush.
Total cooling and fan load not to exceed 1.2A.

See Fig. 1.

Mounts on mounting plate directly on wall. Mounting screws and wall anchors provided.

Setpoint Range:
45°F to 88°F (7°C to 31°C).

Operating Ambient Temperature Range:
40°F to 110°F (4°C to 43°C).

Shipping Temperature Range:
-20°F to 120°F (-29°C to -49°C).

Temperature Display:
Fixed or field selectable.

Operating Relative Humidity:
5 to 90 percent RH; noncondensing.

Time Indication:
12 hour with AM, PM indication.

Cycles Per Hour Adjustment:
Heating: Field adjustable to 3, 6, or 9 cph ±10 percent.
Cooling: Factory set at 3 cph ±10 percent (not field adjustable).

Honeywell T8112D Calibration:
Thermostat and thermometer self-calibrating to ±1.25°F.

Honeywell T8112D Owner's Manual

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