White Rodgers 1E78-144 Installation Manual

The White Rodgers 1E78-144 is a non-programmable digital thermostat for heating and cooling systems. It features simultaneous heat and cool setpoint storage, manual temperature adjustment, and compatibility with various 24V HVAC systems including gas, oil, electric heat, and single-stage heat pumps. Requires 2 AAA batteries. Below are the key specifications, installation, operation, and troubleshooting instructions.

Preparations

Assemble tools required: hand or power drill with 3/16 inch drill bit (if needed), flat blade screwdriver, wire cutter/stripper.

WARNING: Failure to follow and read all instructions carefully before installing or operating this control could cause personal injury and/or property damage.

• 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.
• CAUTION: Before removing wires from old thermostat’s switching subbase, label each wire with the terminal designation it was removed from.
• CAUTION: Take care when securing and routing wires so they do not short to adjacent terminals or rear of thermostat. Personal injury and/or property damage may occur.
• WARNING: Do not use on circuits exceeding specified voltage. Higher voltage will damage control and could cause shock or fire hazard.
• WARNING: Do not short out terminals on gas valve or primary control to test. Short or incorrect wiring will damage thermostat and could cause personal injury and/or property damage.
• WARNING: Thermostat installation and all components of the system shall conform to Class II circuits per the NEC code.

ATTENTION: This product does not contain mercury. However, 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 spilled mercury and place into a container which can be sealed. Mercury must not be discarded in household trash. Refer to www.white-rodgers.com for location to send product containing mercury.

Specifications

Typical System Compatibility Chart	1E78
Standard Heat Only Two Wire Gas or Oil Fired Systems (24 volt)	Yes
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
Heat/Cool Systems Electric Heat (24 volt)	Yes
Heat Only Electric Heat Systems (24 volt)	Yes
Cool Only Systems (24 volt)	Yes
Heat Pump Systems (No Aux. or Emergency Heat)	Yes
Hot Water Zone Heat Only (Two Wire) Systems	Yes
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
VDC Mobile Home Application	Yes
Multistage Systems	No
Systems Exceeding 30VAC, 1.5 Amp	No

Thermostat Details

The thermostat consists of two parts: the thermostat cover and the base. To remove the cover, gently pull it straight out from the base. To replace the cover, line up the cover with the base and press gently until the cover snaps onto the base.

The Thermostat Buttons and Switches:

1. Up arrow: Raises temperature setting.
2. Down arrow: Lowers temperature setting.
3. FAN switch (ON, AUTO).
4. SYSTEM switch (COOL, OFF, HEAT).

The Display:

• Displays current temperature.
• “BATT” displayed when the 2 “AAA” batteries are low and should be replaced. Nothing else will be displayed.
• Displays currently set temperature (this is blank when SYSTEM switch is in the OFF position).

Removing Old Thermostat

1. Remove Old Thermostat: A standard heat/cool thermostat consists of three basic parts: a. 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 the mounting screws that hold it on the wall or adaptor plate.
2. Shut off electricity at the main fuse box until installation is complete. Ensure that the electrical power is disconnected.
3. Remove the front cover of the old thermostat. With wires still attached, remove wall plate from the wall. If the old thermostat has a wall mounting plate, remove the thermostat and the wall mounting plate as an assembly.
4. Identify each wire attached to the old thermostat using the labels enclosed with the new thermostat.
5. Disconnect the wires from the old thermostat one at a time. DO NOT LET WIRES FALL BACK INTO THE WALL.
6. Install new thermostat using the following procedures.

Mounting and Wiring

Electric Heat or Single-Stage Heat Pump Systems: This thermostat is configured from the factory to operate a heat/cool, fossil fuel (gas, oil, etc.), forced air system. It is configured correctly for any system that DOES NOT require the thermostat to energize the fan on a call for heat. If your system is an electric or heat-pump system that REQUIRES the thermostat to turn on the fan on a call for heat, locate the GAS/ELECTRIC switch and switch it to the ELECTRIC position. This will allow the thermostat to energize 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 qualified heating and air conditioning service person.

Hydronic (Hot Water or Steam) Heating Systems: This thermostat is set to operate properly with a forced-air heating system. If you have a hydronic heating system (a system that heats with hot water or steam), you must set the thermostat to operate properly with your system. The factory default setting is forced air heat. Clipping jumper W905 on the circuit board will produce a longer heating cycle which is normally for hot water or steam (hydronic) systems. Both settings produce a very accurate temperature control and can be set to your personal preference. As received, the thermostat cycles the system just under 1°F. With W905 clipped, the system cycles at approximately 1.5°F.

Wiring Diagrams

Figure 2 Description: Typical wiring diagram for heat only, 3-wire, single transformer systems. Connections to RH, W; note for 2-wire heat only attach to RH and W.

Figure 3 Description: Typical wiring diagram for cool only, 3-wire, single transformer systems. RED jumper wire must be used on single transformer systems.

Figure 4 Description: Typical wiring diagram for heat/cool, 4-wire, single transformer systems. Jumper between RH and RC.

Figure 5 Description: Typical wiring diagram for heat/cool, 5-wire, two-transformer systems.

Figure 6 Description: Typical wiring diagram for heat pump with reversing valve energized in COOL. Jumper wires on O/B and Y.

Figure 7 Description: Typical wiring diagram for heat pump with reversing valve energized in HEAT.

1. Remove the packing material from the thermostat. Gently pull the cover straight off the base. Forcing or prying on the thermostat will cause damage to the unit. If necessary, move the electric heat switch.
2. Connect wires beneath terminal screws on base using appropriate wiring schematic.
3. Place base over hole in wall and mark mounting hole locations on wall using base as a template.
4. Move base out of the way. Drill mounting holes.
5. Fasten base loosely to wall using two mounting screws. Adjust until level, and then tighten screws. If using existing mounting holes or holes are too large, use plastic screw anchors.
6. Push excess wire into wall and plug hole with a fire-resistant material (such as fiberglass insulation) to prevent drafts from affecting thermostat operation.

Check Thermostat Operation

NOTE: To prevent static discharge problems, touch side of thermostat to release static build-up before touching any keys. If at any time during testing your system does not operate properly, contact a qualified service person.

Fan Operation

If your system does not have a G terminal connection, skip to Heating System.

1. Turn on the power to the system.
2. Move the FAN switch to ON position. The blower should begin to operate.
3. Move the FAN switch to the AUTO position. The blower should stop immediately.

Cooling System

CAUTION: To prevent compressor and/or property damage, if the outdoor temperature is below 50°F, DO NOT operate the cooling system.

This thermostat has a time delay between cooling cycles to allow the head pressure in the compressor to stabilize. If the temperature is adjusted to call for cool within 5 minutes of the last cycle the snowflake icon will blink indicating the thermostat is locked out. After 3 to 5 minutes, the compressor will start and the snowflake icon will stop flashing. This helps prevent the compressor from cycling too quickly and is normal operation for the thermostat.

1. Move the SYSTEM switch to the COOL position.
2. Press DOWN to adjust thermostat setting below room temperature. The blower should come on immediately on high speed, followed by cold air circulation.
3. Press UP to adjust temperature setting above room temperature. The cooling system should stop operating.

Heating System

1. Move the SYSTEM switch to the HEAT position. If the heating system has a standing pilot, be sure to light it.
2. Press UP to adjust thermostat setting above room temperature. The heating system should begin to operate.
3. Press DOWN to adjust temperature setting below room temperature. The heating system should stop operating.

Operating Features

• SIMULTANEOUS HEATING/COOLING SETPOINT STORAGE: You can enter both your heating and cooling setpoints at the same time. There is no need to re-enter the thermostat at the beginning of each season.
• TEMPERATURE SETTING: Press UP or DOWN arrow until the display shows the temperature you want. The thermostat will keep the room temperature at the selected temperature.
• °F/°C CONVERTIBILITY: The factory default setting is Fahrenheit. Clipping the W904 jumper on the circuit board will alter this feature to Celsius temperature setting.
• LOW BATTERY INDICATOR: If the 2 “AAA” alkaline batteries are low and should be replaced, the display will be blank except for “BATT”. When the batteries are low, pressing any button will cause the display to operate for ten seconds. After ten seconds, the display will be blank except for “BATT”. After “BATT” has been displayed for 4 weeks, the thermostat will raise the temperature 10° above your setpoint in COOL mode and drop the temperature 10° below your setpoint in HEAT mode. You cannot program with low batteries, but you can override the setpoint temperature.
• TEMPERATURE DISPLAY ADJUSTMENT: Your new thermostat has been accurately set in our factory. However, if you wish, you may adjust your new thermostat temperature display to match your old thermostat. This can be accomplished (within a ±3° range) as follows: 1. Press UP and DOWN arrows at the same time for two seconds with the SYSTEM switch in OFF position. 2. Press UP or DOWN to adjust the displayed temperature to your desired setting. 3. Move the SYSTEM switch from OFF to exit the feature.
• DISPLAY BACKLIGHT: The display backlight improves display contrast in low-lighting conditions. Selecting the backlight ON will turn the light on for a short period of time after any button is pressed. Selecting the backlight OFF (default) will keep the light off. Turn the display backlight feature ON as follows: 1. Press UP and DOWN arrows at the same time for two seconds with the SYSTEM switch in the HEAT position. The display will alternately show “-L” AND “FF” (off). 2. Press UP or DOWN to change “FF” to “ON”. 3. Move the SYSTEM switch to OFF to exit the feature.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No Heat/No Cool/No Fan (common problems)	1. Blown fuse or tripped circuit breaker. 2. Furnace power switch to OFF. 3. Furnace blower compartment door or panel loose or not properly installed.	1. Replace fuse or reset breaker. 2. Turn switch to ON. 3. Replace door panel in proper position to engage safety interlock or door switch.
No Heat	1. Pilot light not lit. 2. Loose connection to thermostat or system. 3. Thermostat or heating system requires replacement or service. 4. SYSTEM Switch not set to HEAT.	1. Re-light pilot. 2. Verify thermostat and system wires are securely attached. 3. Your furnace manufacturer or service person can describe how to test the heating system to verify it is operating correctly. If the heating system is capable of operation and the no heat condition persists, replace the thermostat. 4. Set SYSTEM Switch to HEAT and raise temp above room temp.
No Cool	1. Loose connection to thermostat or system. 2. Thermostat or cooling system requires replacement or service. 3. SYSTEM Switch not set to COOL.	1. Verify thermostat and system wires are securely attached. 2. Your cooling system manufacturer or service person can describe how to test the cooling system to verify it is operating correctly. If the cooling system is capable of operation and the no cooling condition persists, replace the thermostat. 3. Set SYSTEM Switch to COOL and lower temp below room temp.
Heat, Cool or Fan Runs Constantly	1. Possible short in wiring. 2. Possible short in thermostat. 3. Possible short in heat/cool/fan system.	Check each wire connection to the thermostat to verify it is neatly looped under the terminals. No extra wire should stick out from under the terminals.
Furnace Cycles Too Fast or Too Slow (narrow or wide temperature swing)		The cycle rate is fixed. The location of the thermostat, size of the Heat/Cool System and current draw can influence the cycle rate. Contact a local service person for additional suggestions.
Cooling Cycles Too Fast or Too Slow (narrow or wide temperature swing)	1. Poor thermostat location for sensing room temperature. 2. Cooling system over or undersized. 3. Excessive Current draw influencing thermostat.	The cycle rate for cooling can not be adjusted. The location of the thermostat, size of the Cool system and current draw can influence the cycle rate. Contact a local service person for suggestions.
Thermostat Setting and Thermostat Thermometer Disagree	1. Thermostat thermometer setting requires adjustment.	The thermometer can be adjusted by using a standard slotted screwdriver. Turn the thermometer pointer screw located inside the front cover to change the setting. For calibrating the setting lever contact a local heating and cooling service person.
Blank Display and/or Keypad Not Responding	Battery or RC wire problem.	Replace batteries and check heat/cool system for proper operation. If a voltage spike occurs use the Reset Operation listed above.