Emerson 1F82-0261 Heat Pump Thermostat installation and operating instruction

Emerson-logoEmerson 1F82-0261 Heat Pump Thermostat

Emerson 1F86-0244 Single-Stage Thermostat-product



Thermostat Configuration Options Thermostat Applications Maximum Stages Heat/Cool
Heat Pump

Single Stage Compressor

Single Stage Compressor

Heat Pump Systems – 1 Stage Aux/Emergency Heat



Electrical Rating:

  • Battery Power or Hardwire………………………… 20 VAC, 50/60 Hz
  • Terminal Load………………………………………………… 1.0 A per terminal, 1.5A maximum all terminals combined
  • Setpoint Range………………………………………………. 45° to 90°F (7° to 32°C)
  • Differential (Heat Pump)………………………………….. Heat 1.2°F; Cool 1.2°F (adjustable)
  • Operating Ambient………………………………………….. 32° to +105°F (0° to +41°C)
  • Operating Humidity…………………………………………. 90% non-condensing max.
  • Shipping Temperature Range…………………………… -40° to +150°F (-40° to +65°C)
  • Dimensions Thermostat…………………………………… 3-3/4”H x 4-3/4”W x 1-1/2”D


To prevent electrical shock and/or equipment damage, disconnect electric power to the system at the main fuse or circuit breaker box until installation is complete.

  • Do not use on circuits exceeding specified voltage.
  • Higher voltage will damage control and could cause shock or fire hazards.
  • Do not short out terminals on gas valve or primary control to test. Short or incorrect wiring will damage the thermostat and could cause personal injury and/or property damage.
  • Thermostat installation and all components of the system shall conform to Class II (current limited) circuits per the NEC code. Failure to do so could cause a fire hazard.



  1. Shut off electricity at the main fuse box until installation is complete. Ensure that the electrical power is disconnected.
  2. Remove the front cover of the old thermostat. With wires still attached, remove the 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.
  3. Identify each wire attached to the old thermostat using the labels enclosed with the new thermostat.
  4. Disconnect the wires from the old thermostat one at a time. DO NOT LET WIRES FALL BACK INTO THE WALL.
  5. Install a new thermostat using the following procedures.

This product does not contain mercury. However, this product may replace a unit that contains mercury.
Do not open mercury cells. If a cell becomes damaged, do not touch any spilled mercury. Wearing nonabsorbent gloves, take up the spilled mercury and place into a container which can be sealed. If a cell becomes damaged, the unit should be discarded.
Mercury must not be discarded in household trash. When the unit this product is replacing is to be discarded, place in a suitable container. Refer to www.white-rodgers.com for a location to send the product containing mercury.


  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.
  2. Place the base over the hole in the wall and mark mounting hole locations on the wall using the base as a template (see Fig.1).
  3. Move the base out of the way. Drill mounting holes.
  4. Push wires through the opening in the thermostat base.
  5. Fasten the base loosely to the wall using two mounting screws.
    Place a level against the bottom of the base, adjust until level, and then tighten the screws. (Leveling is for appearance only and will not affect thermostat operation.) If you are using existing mounting holes, or if the holes drilled are too large and do not allow you to tighten the base snugly, use plastic screw anchors to secure sub base.
  6. Connect wires to terminals on the base using the appropriate wiring schematic (see figs. 2 through 4).
  7. Push excess wire into the wall and plug the hole with a fire-resistant material (such as fiberglass insulation) to prevent drafts from affecting thermostat operation.


The O/B switch on this thermostat is factory set to the “O” position. This will accommodate the majority of heat pump applications, which require the changeover relay to be energized in COOL. If the thermostat you are replacing or the heat pump installed with this thermostat requires a “B” terminal, to energize the changeover relay in HEAT, the O/B switch must be moved to the “B” position.

Emerson 1F86-0244 Single-Stage Thermostat-fig.1

If your system is a heat pump, the GAS/ELEC Switch must be set to ELEC (see Fig. 1) If your system is a single stage, the switch must be set to GAS. The switch setting must agree with the system configuration selected in the configuration menu.


Emerson 1F86-0244 Single-Stage Thermostat-fig.1

Two “AA” alkaline batteries are installed in your thermostat with a battery tag to prevent power drainage. Prior to use, open the battery door and remove the battery tag. To open, pull the battery door as shown by the arrow and lift it open. The two “AA” batteries will operate all functions or maintain time and continuously display the temperature during a loss of AC power. To replace batteries, pull the battery door shown by the arrow and lift it open. Using the polarity indicated inside the battery door, insert the batteries. To close the battery door, swing the door down while pulling in the direction of the arrow. Once fully down, snap the door back into position. The thermostat can be powered by system AC power or a Battery.

IfEmerson 1F86-0244 Single-Stage Thermostat-fig.3 is displayed, the thermostat is battery-powered. If is Emerson 1F86-0244 Single-Stage Thermostat-fig.3not displayed, the thermostat is a system powered with optional battery backup. When the battery power remaining is approximately half, they Emerson 1F86-0244 Single-Stage Thermostat-fig.4will be displayed. When “ChangeEmerson 1F86-0244 Single-Stage Thermostat-fig.4 ” is displayed, install fresh “AA” alkaline batteries immediately. For best results, use new premium brand alkalines batteries such as Duracell® or Energizer®. We recommend replacing batteries every 2 years. If the home is going to be unoccupied for an extended period (over 3 months) and isEmerson 1F86-0244 Single-Stage Thermostat-fig.4 displayed, the batteries should be replaced before leaving. When less than two months of battery life remain, the setpoint temperature will offset by 10 degrees (10 degrees cooler in Heat mode / 10 degrees warmer in Cool mode). If offset occurs, the normal setpoint can be manually reset with Emerson 1F86-0244 Single-Stage Thermostat-fig.5 . Another offset will occur within two days if batteries are not replaced. To replace the batteries, set the system to OFF.


When the EMR feature is activated the thermostat’s microcomputer calculates the time it will take to change the room temperature to the next heat or cool program setting. Then the thermostat will start the system before the next programmed period so that the desired temperature is reached at or near the beginning of the period (the thermostat calculates 15 minutes for every 1°F temperature change). This feature provides better efficiency by allowing gradual temperature changes.
For example
The thermostat is programmed to provide an overnight heating temperature of 66°F, and during the next program period, beginning at 6:00 AM, the programmed temperature is 70°F. With EMR activated, the thermostat will automatically start the heating system at 5:00 AM, so that the programmed temperature of 70°F is reached by about 6:00 AM. If the overnight room temperature drops only to 68°F, the thermostat will start the system at 5:30 to reach the programmed temperature of 70°F at 6:00. The thermostat is shipped with the EMR feature active, which means that the thermostat will start the heating system before the beginning of the next program period. To deactivate the EMR function, see the Configuration menu on Page 5). The thermostat will then wait until the programmed time to start the system for a temperature change.


Emerson 1F86-0244 Single-Stage Thermostat-fig.6


Before you begin using your thermostat, you should be familiar with its features and with the display and the location and operation of the thermostat buttons and switches. Your thermostat consists of two parts: the thermostat cover and the base. To remove the cover, pull it straight out from the base. To replace the cover, line up the cover with the base and press until the cover snaps onto the base. The Thermostat Buttons and Switches.

Emerson 1F82-0261 Heat Pump Thermostat-fig.1

  1. Raises temperature setting.
  2. Lowers temperature setting.
  3. TIME button.
  4. SYSTEM switch (COOL, OFF, HEAT).
  5. PRGM (program) button.
  6. FAN switch (ON, AUTO).
  7. RUN/HOLD (program) button.
    The Display
  8. Indicates days of the week.
  9. Indicates setpoint temperature. This is blank when the system switch is in the OFF position. The setpoint temperature is displayed (flashing) if the thermostat is in lockout mode to prevent the compressor from cycling too quickly.
  10. “AUX” indicates the auxiliary stage is operating.
  11. “Save” indicates the Cool Savings feature is enabled in the configuration menu. “Save” (flashing) indicates the Cool Savings feature is active.
  12. The flame icon is displayed when the SYSTEM switch is in the HEAT position. The flame icon Emerson 1F86-0244 Single-Stage Thermostat-fig.9 is displayed flashing when the thermostat is calling for heat. Snowflake icon ( ) is displayed (non-flashing) when the SYSTEM switch is in the COOL position. A snowflake iconEmerson 1F86-0244 Single-Stage Thermostat-fig.9 is displayed(flashing) if the thermostat is calling for cool.
  13. Displays current temperature.
  14. “Service” indicates a diagnostic fault in the heating/cooling system. It does not indicate a fault in the thermostat.
  15. “EMER” is displayed flashing when the system switch is in the EMER position.
  16. “Change Filter” is displayed when the system has run for the programmed filter time period as a reminder to change or clean your air filter.
  17. Emerson 1F86-0244 Single-Stage Thermostat-fig.3 indicates the power level of batteries. “Change Emerson 1F86-0244 Single-Stage Thermostat-fig.4” indicates batteries should be replaced.
  18. Indicates time.
  19. “A” “P” indicates time as Morning (A) or Evening (P).
  20. “Temp Hold” indicates temporary hold or “Hold” indicates hold mode.


The configuration menu allows you to set certain thermostat operating characteristics to your system or personal requirements. To enter the menu: Set your thermostat to OFF Emerson 1F86-0244 Single-Stage Thermostat-fig.5 press the and buttons simultaneously. The display will show the first item in the configuration menu. Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5 to change to the next menu item. To exit the menu, set the system switch to Cool or Heat. If no keys are pressed within fifteen minutes, the thermostat will revert to normal operation.

Configuration Menu

Menu Reference Number Heat Pump Press Key Displayed (Factory Default) Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5  to select from the listed options Comments
1 1 RUN/HOLD* CS (OFF) On Select Cool Savings Feature On or OFF
RUN/HOLD* CS (3) 1, 2, 3, 4, 5, 6 If CS selected On, selects Cool Savings value
2 2 RUN/HOLD* E (On) OFF Select Energy Management Recovery On or OFF
3 3 RUN/HOLD* CR HE-PU (FA) SL Select Adjustable Anticipation, cycle rate, Heat Pump, Heat and Cool
4 4 RUN/HOLD* CR Aux (FA) SL Select Adjustable Anticipation, cycle rate, Heat Pump Aux Stage
5 5 RUN/HOLD* CL (OFF) On Select Compressor lockout OFF or On
6 6 RUN/HOLD* L (On) OFF Select Display Light On or OFF
7 7 RUN/HOLD* Temp (0 HI) 4 LO to

4 HI

Select temperature display adjustment higher or lower
8 8 RUN/HOLD* oF oC Select oF / oC Display (temperature units in Fahrenheit or Celsius)
9 9 RUN/HOLD* FH (On) OFF Select fast second stage On or OFF
10 10 RUN/HOLD* Change Filter (OFF) On Select filter replacement indicator OFF or On
RUN/HOLD* Change Filter (200 h) 25 to 1975 If Change Filter selected On, selects time interval for Change Filter Indicator.

(in 25 hour increments)

11 RUN/HOLD* Returns to normal operation

*Press RUN/HOLD to advance to next item or TIME to move backward to the previous item

  1. Select CS (Cool Savings™) – With Cool Savings™ enabled, the thermostat will make small adjustments to the Setpoint temperature during periods of high demand to reduce cooling system running time and save energy. When the cooling system has been running for more than 20 minutes, humidity in the home will be lower and a higher setpoint temperature will feel comfortable. After 20 minutes of run time, the thermostat will start increasing the setpoint temperature in steps of less than one degree as the system continues to run. These adjustments will eventually cause the system to satisfy the thermostat and turn the system off to reduce energy consumption. When the Cool Savings feature is active and making adjustments, the display will show “Save”. The amount of adjustments to the setpoint temperature is dependent on the Cool Savings value that is set, 1 being the least adjustment and 6 being the most adjustment. With this feature set to OFF, no change will occur when the cooling system is continuously running during the periods of high demand. Periods of high demand will normally occur during the late afternoon and early evening on the hottest days of the summer.
  2. Select Energy Management Recovery – Energy Management Recovery (E) On enables the thermostat to start heating or cooling early to make the building temperature reach the program setpoint at the time you specify. See page 3 for details.
  3. Select Cycle Rate Selection – The factory default setting for Single Stage Heat is Medium Cycle (ME). For Single Stage Cool the default setting is fast (FA). To change cycle rate, press the Emerson 1F86-0244 Single-Stage Thermostat-fig.5 buttons.
    The cycle rate differentials for different settings are:Emerson 1F89-0211 Heat Pump Thermostat-fig.2
  4. Select Compressor Lockout CL OFF or ON – Selecting CL On will cause the thermostat to wait 5 minutes between cooling cycles. This is intended to help protect the compressor from short cycling. Some newer compressors already have a time delay built in and do not require this feature. Your compressor manufacturer can tell you if the lockout feature is already present in their system. When the thermostat compressor time delay occurs, it will flash the setpoint for up to five minutes.
  5. Select Backlight Display – The display backlight improves display contrast in low lighting conditions. When the “C” terminal is connected, selecting backlight CdL On will keep the light on continuously. Select backlight OFF will turn the light on momentarily when any key is pressed. When the “C” terminal is not connected, regardless of the backlight selection, the light will be on momentarily when any key is pressed.
  6. Select Temperature Display Adjustment 4 LO to 4 HI – Allows you to adjust the room temperature display up to 4° higher or lower. Your thermostat was accurately calibrated at the factory but you have the option to change the display temperature to match your previous thermostat. The current or adjusted room temperature will be displayed on the display.
  7. Select F° or C° Readout – Changes the display readout to Celsius or Fahrenheit as required.
  8. Select Fast Second Stage ON or OFF – (Heat Pump Only) In the RUN mode, with the Fast Heat feature enabled (FH Heat On), if the temperature is manually raised by 3°F (2°C) or more above the actual temperature using the , the second stage will energize immediately. With FH OFF, the thermostat will determine the optimum time (approximately 0 to 30 minutes) to use Auxiliary/Second stage heat in addition to the Heat Pump.
  9. Select Filter Replacement Reminder and Set Run Time Select the “Change Filter” reminder On or OFF. If selected On, press Emerson 1F86-0244 Single-Stage Thermostat-fig.5 to select the time period from 25 to 1975 hours in 25 hour increments. In a typical application, 200 hours (default) of run time is approximately 30 days. After the selected time of blower operation, the thermostat will display “Change Filter” as a reminder to change or clean your air filter. When “Change Filter” is displayed, press the Emerson 1F86-0244 Single-Stage Thermostat-fig.5 button to clear the display and restart the time to the next filter change. A selection of OFF will cancel this feature.
  10. Select RUN/HOLD – Exit Menu.



If at any time during testing your system does not operate properly, contact a qualified service person.
Turn on power to the system.
Fan Operation
If your system does not have a G terminal connection, skip to Heating System.

  1. Move the fan switch to the ON position. The blower should begin to operate.
  2. Move the fan switch to the AUTO position. The blower should stop immediately.

Heating System

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

Emergency System
EMER bypasses the Heat Pump to use the heat source wired to terminal W2 on the thermostat. EMER is typically used when compressor operation is not desired, or you prefer back-up heat only.

  1. Move the SYSTEM switch to the EMER position, and EMER will flash on the display.
  2. Press to adjust the thermostat above room temperature. The Aux heating system will begin to operate. The Flame icon ( ) will display flashing to indicate that the Aux system is operating.
  3. Press to adjust the thermostat below room temperature. The Aux heating system should stop operating.

Cooling System


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

  1. Move the SYSTEM switch to the COOL position.
  2. Press to adjust the thermostat setting below room temperature. The blower should come on immediately on high speed, followed by cold air circulation. However, if the setpoint temperature is flashing, the compressor lockout feature is operating (see Configuration menu, item 5).
  3. Press to adjust the temperature setting above room temperature. The cooling system should stop operating.



Do not allow the compressor to run unless the compressor oil heaters have been operational for 6 hours and the system has not been operational for at least 5 minutes.


  • HOLD TEMPERATURE — With the SYSTEM switch set to HEAT or COOL, momentarily press the RUN/HOLD button. HOLD will be displayed. Use Emerson 1F86-0244 Single-Stage Thermostat-fig.5 to adjust the temperature. The thermostat will hold the room temperature at the selected setting until you press the RUN/HOLD button to start the program operation again.
  • TEMPERATURE OVERRIDE (TEMPORARY HOLD) — Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5 until the temperature you want is displayed. The thermostat will override current programming and keep the room temperature at the selected temperature for 2 hours or until the next program period begins. Then the thermostat will automatically revert to the program.


This section will help you plan your thermostat’s program to meet your needs. For maximum comfort and efficiency, keep the following guidelines in mind when planning your program.

  • When heating (cooling) your building, program the temperatures to be cooler (warmer) when the building is vacant or during periods of low activity.
  • During early morning hours, the need for cooling is usually minimal.

Planning Your Program
Look at the factory preprogrammed times and temperatures are shown in the sample schedule. If this program will suit your needs, simply press the RUN/HOLD button to begin running the factory preset program.
If you want to change the preprogrammed times and temperatures, follow these steps.
Determine the time periods and temperatures for your program. You must program four periods for each day. However, you may use the same heating and cooling temperatures for consecutive time periods. You can choose start times, heating temperatures, and cooling temperatures independently (for example, you may select 5:00 AM and 70° as the daily 1st period heating start time and temperature, and also choose 7:00 AM and 76° as the daily 1st period cooling start time and temperature).
Use the table to plan your program time periods and the temperatures you want during each period. Fill in the complete table to have a record of your programs.

Entering Your Program
Set Current Time and Day

  1. Press the TIME button once. The display will show the hour only.
    EXAMPLE:Emerson 1F80-0224 Single-Stage Thermostat-fig
  2. Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5hold either or until you reach the correct hour and AM/PM designation (AM begins at midnight; PM begins at noon).
  3. Press TIME once again. The display window will show the minutes only.
    EXAMPLE:Emerson 1F80-0224 Single-Stage Thermostat-fig
  4. Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5 hold either or until you reach the correct minutes.
  5. Press TIME once again. The display will show the day of the week.
  6. PressEmerson 1F86-0244 Single-Stage Thermostat-fig.5 until you reach the current day of the week.
  7. Press RUN/HOLD once. The display will show the correct time, day, room temperature, and set-point temperature.

Enter Heating Program

  1. Move the SYSTEM switch to HEAT.
  2. Press PRGM once. “Mo Tu We Th Fr Sa Su” (indicating daily program) will appear in the display. Also displayed are the currently programmed start time for the 1st heating period and the currently programmed temperature (flashing).
    EXAMPLE:Emerson 1F80-0224 Single-Stage Thermostat-fig
    This display window shows that for the 1st weekday period, the start time is 6:00 AM, and 70° is the programmed temperature (this example reflects factory preprogramming).
  3. Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5 to change the displayed temperature to your selected temperature for the 1st heating program period.
  4.  Press TIME once (the programmed time will flash). Press Emerson 1F86-0244 Single-Stage Thermostat-fig.5 until your selected time appears. The time will change in 15-minute increments. When your selected time is displayed, press TIME again to return to the change temperature mode.
  5. Press PRGM once. The currently programmed start time and setpoint temperature for the 2nd heating program period will appear.
  6. Repeat steps 3 and 4 to select the start time and heating temperature for the 2nd heating program period.
  7. Repeat steps 3 through 5 for the 3rd and 4th heating program periods.
  8. Press PRGM once. “SA” (indicating Saturday program) will appear in the display, along with the start time for the 1st heating period and the currently programmed temperature.
  9. Repeat steps 3 through 7 to complete Saturday heating programming.
  10. Press PRGM once to change to SU (Sunday) heating programming and repeat steps 3 through 7 to complete Sunday programming.
  11. When you have completed entering your heating program, press RUN/HOLD.

Emerson 1F82-0261 Heat Pump Thermostat-fig.3

Enter Cooling Program


If the outside temperature is below 50oF, disconnect power to the cooling system before programming. Energizing the air conditioner compressor during cold weather may cause personal injury or property damage.

  1. Move SYSTEM switch to COOL position.
  2. Follow Enter Heating Program for entering your cooling program, using your selected cooling times and temperatures.

Follow these steps to check your thermostat programming one final time before beginning thermostat operation.

  1. Move the SYSTEM switch to the HEAT position.
  2. Press PRGM to view the 1st weekday heating period time and temperature. Each time you press PRGM, the next heating period time and temperature will be displayed in sequence for weekday, then Saturday and Sunday program periods (you may change any time or temperature during this procedure).
  3. Press RUN/HOLD.
  4. Move SYSTEM switch to COOL position.
  5. Repeat step 2 to check cooling program.
  6. Move SYSTEM switch to HEAT or COOL and press RUN/ HOLD to begin program operation.


Reset Operation

If a voltage spike or static discharge blanks out the display or causes erratic thermostat operation, you may need to reset the thermostat. To reset, the System Switch must be in Cool or Heat. Simultaneously press Emerson 1F86-0244 Single-Stage Thermostat-fig.5  buttons for approximately 10 seconds until the display goes blank. If the thermostat has power, has been reset and still does not function correctly contact your heating/cooling service person or place of purchase.

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.

Replace fuse or reset breaker. Turn switch to ON.

Replace door panel in proper position to engage safety interlock or door switch.

No Heat 1. System Switch not set to Heat.


2. Loose connection to thermostat or system

3. Heating System requires service or thermostat requires replacement.

Set System Switch to Heat and raise setpoint above room temperature.

Verify thermostat and system wires are securely attached.


Diagnostic: Set System Switch to Heat and raise the setpoint above room temperature. Within a five minutes the thermostat should make a soft slick sound. This sound usually indicates the thermostat is operating properly. If the thermostat does not click, try the reset operation listed above. If the thermostat does not click after being reset

contact your heating and cooling service person or place of purchase for a replacement. If the thermostat clicks, con- tact the furnace manufacturer or a service person to verify the heating system is operating correctly.

No Cool 1. System Switch not set to Cool.


2. Loose connection to thermostat or system.

3. Cooling System requires service or thermostat requires replacement

Set System Switch to Cool and lower setpoint below room temperature.

Verify thermostat and system wires are securely attached. Same procedures as diagnostic for No Heat condition except set the thermostat to Cool and lower the setpoint below the room temperature. There may be up to a five minute delay before the thermostat clicks in Cooling if the compressor lock-out option is selected in the configuration menu (Item 6).

Heat, Cool or Fan Runs Constantly 1. Possible short in wiring.

2. Possible short in thermostat.

3. Possible short in Heat/Cool/Fan system.

4. Fan Switch set to Fan On.

Check each wire connection to verify they are not shorted or touching together. No bare wire should stick out from under terminal screws. Try resetting the thermostat as described below. If the condition persists, the manufacturer of your system or service person can instruct you on how to test the Heat/Cool/ system for correct operation. If the system operates correctly, replace the thermostat.
Furnace Cycles Too Fast or Too Slow (narrow or wide temperature swing) 1. The location of the thermostat and/or the size of the Heating System may be influencing the cycle rate. Item 4 in the Configuration Menu is the adjustment that controls the cycle rate. If an acceptable cycle rate is not achieved using the FA (Fast) or SL (Slow) adjustment con- tact a local service person for additional suggestions.
Cooling Cycles Too Fast or Too Slow (narrow or wide temperature swing) 1. The location of the thermostat and/or size of the Cooling System may be influencing the cycle rate. The cycle rate for cooling is fixed and can not be adjusted. Contact a local service person for suggestions.
Thermostat Setting and Thermometer Disagree 1. Thermostat thermometer setting requires adjustment. The thermometer can be adjusted +/-4 degrees as listed in item 8 of the Configuration Menu. No other adjustment is possible.
Clock Loses or Gains Time 1. Loss of power to thermostat. The thermostat will maintain its program in memory even with no power but the clock time will be incorrect when power is restored. See No Heat/No Cool/No Fan (common problems) above for items to check in the system.
Heat or Cool Starts Early 1. EMR activated. See Configuration Menu (Item 3).
Thermostat Does Not Follow Program 1. AM or PM set incorrectly in program.

2. AM or PM set incorrectly on the clock.

3. Voltage spike or static discharge.

4. See “Heat or Cool Starts Early” above.

Check current clock and program settings including the AM or PM designations for each time period. If a voltage spike or static discharge occurs use the Reset Operation listed above.
Blank Display and/or Keypad Not Responding 1. Voltage Spike or Static Discharge. If a voltage spike or static discharge occurs use the Reset Operation listed above.
Thermostat has HP/SS switch and Configuration Menu has selection for HP or SS 1. Earlier version of thermostat model. If switch is present, it must be in HP position for proper fan operation. If selection appears in Configuration Menu, it must be set for HP.


Second Stage – Auxiliary Heat

Most heat pump systems have an Auxiliary or Second Stage electric heater or gas furnace. The heat produced by a heat pump is economical but may not always have the capacity to maintain a comfortable room temperature setting. Auxiliary/Second Stage heat is usually less economical but the added heat capacity assures the system can provide enough heat to satisfy the thermostat setting. Digital thermostats have a built-in function that computes the optimum time (approximately 0-30 minutes) to use Auxiliary / Second Stage heat in addition to the Heat Pump heat.

Typical operation:

  • In moderate weather with a low-temperature setting (low demand), the thermostat may use only the heat pump to maintain temperature.
  • In colder weather or higher temperature settings (higher demand), Auxiliary Heat is used occasionally to supplement the heat pump
  • In very cold weather (very high demand) when Heat Pump performance is low Auxiliary Heat is used frequently to maintain comfort.
  • The thermostat automatically adjusts to optimize comfort and economy using the lowest stage practical to make a setpoint. The key to reducing energy costs and minimizing Auxiliary or Second Stage is to set the thermostat to the lowest comfortable heating temperature.


Download Manual: Emerson 1F82-0261 Heat Pump Thermostat installation and operating instruction


Emerson 1F82-0261 Heat Pump Thermostat installation and operating instruction





Leave a Reply

Your email address will not be published. Required fields are marked *