• HEAT: In the “ HEAt” mode a Flame “ “ icon appears on the display, which flickers when the furnace is running. • AUTO (Models 8534 and 8538 only): In the “ AUtO” mode, the heating and cooling system will operate in either the “ HEAt” or “ COOL” mode depending on which current setting the room temperature is closest to. Note that both the Snowflake “ “ and Flame “ “ icons appear on the display. – 7 – 110-7/12/9:14 Page 2. Select the temperature to be used by pressing the DAY/ NIGHT button until

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Getting Familiar With The Aprilaire ® Thermostat. . . . . . . . . . . . . . . . . . . . . . . . . 3 • Temperature Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 • Mode Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 • Temperature Settings – Day/Night Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • Fan Button. . . . . . . .

When the thermostat is calling for heat, the flame flickers and the snowflake goes off. When cooling, the snowflake flickers and the flame goes off. LIMITED OVERRIDE When the keyboard is locked (DIP switch #2 ON), the user may override the temperature setpoint hour by pressing either the . or . button. The range of temperature override is ±6°F or the programmed daytime setpoint. Your new digital thermostat has been designed to provide accurate control and display of room temperature. In addition

See Fig. 3. Set base aside. 3 Figure 3 PROG MAN CHANGE SET AUTO/MAN Elec Gas RHAM PM MORN DAY EVE NITE RC W Y G FAN AUTO ON MOUNTING HOLES COOL OFF HEAT 7. Drill the marked holes using a 3/16” drill bit. Note: Enclosed plastic anchors do not require a drilled hole for drywall. 8. Tap plastic anchors into the wall. 9. Align base with plastic anchors and feed wires through opening. See Fig 4. Figure 4 PROG MAN CHANGE SET AUTO/MAN Elec Gas RHAM PM MORN DAY EVE NITE RC W Y G FAN AUTO ONCOOL OFF HEAT

1. Turn power off to the heating and cooling systems. 2. Place COOL-OFF-HEAT In OFF position. 3. Place FAN: AUTO-ON switch Into AUTO position. 4. Remove the cover using a coin or screwdriver. 5. Place thermostat against the wall at desired location. Make sure wires will feed through opening on base of thermostat. 6. Mark placement of mounting holes. See Fig. 3. Set base aside. 7. Drill the marked holes using a 3/16" drill bit. NOTE: Enclosed plastic anchors do not require drilled hole for drywal

The air conditioning system should turn on within a few seconds. NOTE: When in the COOL mode (or HEAT for single stage heat pumps), once the thermostat turns off, a built in 5-minute delay prevents the system from turning on again. This protects the compressor. No additional time delay relay is required. 3. Put the COOL-OFF-HEAT-EM switch into the OFF position. The air conditioning system should turn off. 4. Put the COOL-OFF-HEAT-EM switch into the HEAT position. 5. Press the > button until the

• Read all of the information in this manual before installing or programming this thermostat. • This is a 24V AC low-voltage thermostat. Do not install on voltages higher than 30V AC. • All wiring must conform to local and national building and electrical codes and ordinances. • Do not short (jumper) across terminals on the gas valve or at the system control to test installation. This will damage the thermostat and void the warranty. 1 Features • Four pre-programmed setpoints for each day of th

. . . . . . . . . . . . . . . . . . . . . . .1 Setting Or Changing The Program . . . . . . . . . . . . . . . . . . . . . . . Program Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Setting Or Changing The Weekend Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reviewing Programmed Time Schedules And Temperature Settings . . . . . . . . . . . . . . . . . . . . . 8 To Start Running The Program . . . . . . . . . . . . . . . . . . . . . . . . . . .

Place the thermostat wire opening over the wall opening. If replacing a thermostat, place the thermostat to cover the old thermostat silhouette. The base of the thermostat is raised to allow for wire routing behind the thermostat. 2. Level the thermostat (for appearance only) and mark the mounting hole locations. 3. Drill a 3/16” dia. hole at the marked locations and install drywall anchors (included). Drywall anchors should be used unless installing on paneling or other hard surfaces. Anchors s

This thermostat is not a 120 volt (line voltage) device. Improper installation may cause serious injury from electrical shock. This product must be installed by a qualified heating & air conditioning contractor in accordance with NEC Standards and applicable local and state codes. Mercury is toxic and may be hazardous to your health. Any replaced thermostats containing mercury must be disposed of properly. Contact local authorities for disposal information. SPECIFICATIONS Comfort Range 60°F – 80