Heating & Air Conditioning 1E78

1 CONTENTS. 1. Thermostat 1. Installation Instructions for Removing Old 1. Mounting and 2. Heating & Air Conditioning Check Thermostat 3. Programming your 4. 1E78 6. 5/2 Day Programmable Thermostat 6. YOUR THERMOSTAT REPLACES. Typical System Compatibility Chart 1E78. 1 PREPARATIONS. Standard Heat Only Two Wire Gas or Oil Fired Systems (24 volt) Yes Assemble tools required as shown below. Electronic Ignition Heat Only Two Wire Systems (24 volt) Yes Electronic Ignition Heat Only Gas or Oil Fired Systems (24 volt) Yes Standard Heat/Cool Systems (24 volt) Yes FLAT BLADE SCREWDRIVER. Heat/Cool Systems Electric Heat (24 volt) Yes Heat Only Electric Heat Systems (24 volt) Yes HAND OR POWER. DRILL WITH 3/16 INCH. Cool Only Systems (24 volt) Yes DRILL BIT, IF NEEDED. Heat Pump Systems (No Aux. or Emergency Heat) Yes Hot Water Zone Heat Only (Two Wire) Systems Yes WIRE CUTTER/STRIPPER.

2 Hot Water Zone Heat Only (Three Wire) Systems No Line Voltage Heating or Baseboard 110/240 Volt Systems No Millivolt Systems Floor or Wall Furnaces Yes 12 VDC Mobile Home Application Yes Failure to follow and read all instructions carefully Multistage Systems No before installing or operating this control could cause Systems Exceeding 30 VAC, Amp No personal injury and/or property damage 2 THERMOSTAT DETAILS 3 REMOVING OLD THERMOSTAT. Mounting Hole ! CAUTION. To prevent electrical shock and/or equipment damage, disconnect electrical power to the system at the main fuse or circuit breaker until installation is complete. Before removing wires from old thermostat's switching subbase, label W903. each wire with the terminal designation it was removed from. W904. RC G RH W 1. Remove Old Thermostat: A standard heat/cool thermostat Y O B. consists of three basic parts: W905 a.

3 The cover, which may be either a snap-on or hinge type. b. The base, which is removed by loosening all captive screws. c. The switching subbase, which is removed by unscrewing ELEC GAS. the mounting screws that hold it on the wall or adaptor plate. 2. Shut off electricity at the main fuse box until installation is com- Elec/Gas plete. Ensure that electrical power is disconnected. Mounting Back of Switch Base 3. Remove the front cover of the old thermostat. With wires still Hole Thermostat Body attached, remove wall plate from the wall. If the old thermostat W903 - clip to disable EMR feature has a wall mounting plate, remove the thermostat and the wall W904 - clip for Celcius display mounting plate as an assembly. W905 - clip for hydronic system 4. Identify each wire attached to the old thermostat. NOTE: Earlier models refer to 37-7006 for jumper locations.

4 5. Disconnect the wires from the old thermostat one at a time. DO. Figure 1. Thermostat NOT LET WIRES FALL BACK INTO THE WALL. 6. Install new thermostat using the following procedures. PART NO. 37-6542C. Replaces 37-6542B. 1026. 3 REMOVING OLD THERMOSTAT ! CAUTION. CONTINUED FROM FIRST PAGE Take care when securing and routing wires so they do not short to adjacent terminals or rear of thermostat. Personal ATTENTION! This product does not contain mercury. However, injury and/or property damage may occur. this product may replace a unit which contains mercury. Do not open mercury cells. If a cell becomes damaged, do not touch any spilled mercury. Wearing non-absorbent gloves, take up the TERMINAL CROSS REFERENCE CHART. spilled mercury and place into a container which can be sealed. If a cell becomes damaged, the unit should be discarded. New Thermostat Other Manufacturers'.

5 Mercury must not be discarded in household trash. When the unit Terminal Designation Terminal Designation * *. this product is replacing is to be discarded, place in a suitable con- RH 4 RH M R5 R. tainer. Refer to for location to send product RC R R V - - containing mercury. G G G F G G. W W W H 4 W. 4 MOUNTING AND WIRING Y Y Y C Y6 Y. * These are four-wire, single-transformer systems. Factory installed jumper wire between the RH. ! WARNING and RC terminals must remain in place. Do not use on circuits exceeding specified voltage. Higher voltage will damage control and could cause shock or fire hazard. Energy Management Recovery (EMR). Do not short out terminals on gas valve or primary control This thermostat is set to operate with EMR. This causes the to test. Short or incorrect wiring will damage thermostat and thermostat to start the Heating or cooling system early to have could cause personal injury and/or property damage.

6 The room temperature reach the program setpoint at the time the period is to start. Thermostat installation and all components of the system shall conform to Class II circuits per the NEC code. To disable EMR, clip jumper W903 (see Fig. 1). Attach Thermostat Base to Wall Electric Heat or Single-Stage 1. Remove the packing material from the thermostat. Gently pull the Heat Pump Systems thermostat body straight off the base. Forcing or prying on the This thermostat is configured from the factory to operate a heat/cool, thermostat will cause damage to the unit. If necessary, move the fossil fuel (gas, oil, etc.), forced air system. It is configured correctly electric heat switch (see ELECTRIC HEAT SYSTEMS, above). for any system that DOES NOT require the thermostat to energize 2. Connect wires beneath terminal screws on base using appropri- the fan on a call for heat.

7 If your system is an electric or heat-pump ate wiring schematic (see figs. 2 through 7). system that REQUIRES the thermostat to turn on the fan on a call 3. Place base over hole in wall and mark mounting hole locations for heat, locate the GAS/ELECTRIC switch (see fig. 1) and switch it on wall using base as a template. to the ELECTRIC position. This will allow the thermostat to energize 4. Move base out of the way. Drill mounting holes. the fan immediately on a call for heat. If you are unsure if the Heating /. cooling system requires the thermostat to control the fan, contact a 5. Fasten base loosely to wall, as shown in fig. 1, using two mount- qualified Heating and air Conditioning service person. ing screws. Adjust until level, and then tighten screws. (Leveling is for appearance only and will not affect thermostat operation.). If you are using existing mounting holes, or if holes drilled are Hydronic (Hot Water or Steam) too large and do not allow you to tighten base snugly, use plastic Heating Systems screw anchors to secure subbase.

8 This thermostat is set to operate properly with a forced-air Heating 6. Push excess wire into wall and plug hole with a fire-resistant system. If you have a hydronic Heating system (a system that heats material (such as fiberglass insulation) to prevent drafts from with hot water or steam), you must set the thermostat to operate affecting thermostat operation. properly with your system. The factory default setting is forced air heat. Clipping jumper W905 on Battery Location the circuit board will produce a longer Heating cycle which is normally This thermostat requires 2 AAA alkaline batteries to operate. for hot water or steam (hydronic) systems. Both settings produce a If appears on the display, the batteries are low and should be very accurate temperature control and can be set to your personal replaced with fresh AAA Energizer alkaline batteries.

9 The batteries . preference. As received, the thermostat cycles the system just under are located on the back of the thermostat body (see fig. 1). 1 F. With W905 clipped, the system cycles at approximately F. 4 MOUNTING AND WIRING CONTINUED FROM SECOND PAGE. JUMPER THERMOSTAT. WIRE B O Y G W RC RH. THERMOSTAT SYSTEM. B O Y G W RC RH. SYSTEM Hot Cooling Fan Heating 24 VAC 120 VAC. System Relay System Fan Heating Neutral Relay System Hot Heating . 24 VAC TRANSFORMER. NOTE 120 VAC. For 2-wire Heat only, Neutral Hot attach to RH and W. TRANSFORMER 24 VAC 120 VAC. Neutral Figure 2. Typical wiring diagram for COOLING TRANSFORMER. heat only, 3-wire, single transformer systems Figure 5. Typical wiring diagram for JUMPER. WIRE heat/cool, 5-wire, two-transformer systems THERMOSTAT. B O Y G W RC RH. SYSTEM JUMPER JUMPER. WIRE WIRE. Cooling Fan THERMOSTAT.

10 B O Y G W RC RH. System Relay Hot SYSTEM. 24 VAC 120 VAC. Neutral Reversing Compressor Fan Valve* Contactor Relay Hot TRANSFORMER. 24 VAC 120 VAC. Figure 3. Typical wiring diagram for * Reversing valve is energized when the Neutral system switch is in the COOL position cool only, 3-wire, single transformer systems TRANSFORMER. Figure 6. Typical wiring diagram for heat pump NOTE with reversing valve energized in COOL. RED jumper wire (provided with thermostat) must be connected between thermostat RH and RC terminals JUMPER. for proper thermostat operation with this system. WIRE JUMPER JUMPER. WIRE WIRE. THERMOSTAT. B O Y G W RC RH THERMOSTAT. SYSTEM B O Y G W RC RH. SYSTEM. Cooling Fan Heating Reversing Compressor Fan System Relay System Hot Valve* Contactor Relay Hot 24 VAC 120 VAC 24 VAC 120 VAC. * Reversing valve is energized when the Neutral Neutral system switch is in the HEAT position TRANSFORMER.