Emerson 1F98EZ-1421 Thermostat Operation Manual

The Emerson 1F98EZ-1421 is a Blue Easy Install Programmable Thermostat designed for single-stage, multi-stage, or heat pump systems, offering 7-day or non-programmable modes. It features a 12-inch touchscreen display, automatic heat/cool changeover, and a 4-wire system for easy installation. Below are the key specifications and operation instructions.

1. Key Specifications 2. Operation Instructions 2.1. Initial Setup 2.2. Setting the Clock and Day 2.3. Operating in Non-Programmable Mode 2.4. Operating in Programmable Mode 2.5. Advanced Features 2.6. Troubleshooting 3. Installation Instructions 3.1. Remove Old Thermostat 3.2. Installing New Thermostat 3.3. Battery Location 3.4. Power Stealing Switches

Key Specifications

Type: Programmable (7-day) or non-programmable, universal touchscreen thermostat
Compatibility:
- Single-stage systems (gas, oil, electric)
- Multi-stage systems (gas, oil, electric)
- Heat pump systems (up to 4H/2C, including dual fuel)
- Not compatible with systems exceeding 30 VAC or electric baseboard heat
Power Source:
- Battery: 2 AA alkaline batteries (Duracell or Energizer recommended)
- Hardwired: 20-30 VAC, NEC Class II, 50/60 Hz with common (C) wire
- Power Stealing Assist for systems without C wire
Electrical Rating:
- Terminal Load: 1.5 A per terminal, 2.5 A max combined
- Rated Differentials (@ 6°F/Hr):
  - Heat (Single Stage/Multi-Stage): Fast 0.6°F, Slow 1.5°F
  - Cool (Single Stage/Multi-Stage): Fast 1.2°F, Slow 1.7°F
  - Heat Pump: Fast 1.2°F, Slow 1.7°F
  - Emergency Heat: Fast 0.6°F, Slow 1.7°F
- Setpoint Range: 45°F to 99°F (7°C to 37°C)
Display: 12-square-inch touchscreen LCD with backlight
Operating Conditions:
- Ambient: 32°F to 105°F (0°C to 41°C)
- Humidity: 90% non-condensing max
- Shipping: -4°F to 150°F (-20°C to 65°C)
Dimensions: 4-9/16” H x 5-13/16” W x 1-3/16” D
Features:
- 7-day programmable scheduling with 4 periods per day
- Automatic heat/cool changeover
- Keypad lockout with PIN (000-999)
- Temperature offset adjustment (±5°F)
- Maintenance reminders (e.g., filter, humidifier pad)
- Compressor protection (adjustable delay)
- Energy-saving pre-programmed schedules
- 4-wire easy installation
- System problem detection with “Call for Service” alert
Thermostat Configuration Options:
- Single Stage (SS1): Gas, Oil, Electric, Heat Only, Cool Only, or Heat/Cool Systems - Maximum Stages Heat/Cool: 1/1
- Multi Stage (MS2): Gas, Oil, Electric - Maximum Stages Heat/Cool: 2/2
- Heat Pump (HP1/HP2): Single or Multi-Stage Compressor Heat Pump Systems, up to 4 Stages Heat/2 Stages Cool - Maximum Stages Heat/Cool: 4/2

Operation Instructions

Initial Setup

1. Insert Batteries: Install 2 AA alkaline batteries in the rear compartment to keep time during power outages, removing the battery tag to activate. Replace when “LOW BATTERY” appears in the scrolling message area (approximately every 2 years).
2. Power On: Ensure 20-30 VAC is supplied via the C terminal for hardwired operation. The touchscreen should display the home screen with time, temperature, and system status.
3. Configure System:

Press MENU, then hold the Thermostat Options Configuration Menu key for 5 seconds.
Select system type (SS1, MS2, HP1, HP2), program days per week (7 or 0 for non-programmable), temperature offset (±5°F), and maintenance reminders (e.g., humidifier pad).
Exit by pressing RUN SCHEDULE or waiting for the display to return to normal.

Setting the Clock and Day

1. Press MENU, then select SET TIME.
2. Use up/down arrows to adjust hours, minutes, and AM/PM.
3. Select SET DAY and adjust to the current day of the week.
4. Press RUN SCHEDULE to save and exit.

Operating in Non-Programmable Mode

1. Select Mode: Press SYSTEM to choose HEAT, COOL, AUTO, EM (emergency heat for heat pumps), or OFF. When AUTO is selected, the thermostat switches between Heat and Cool based on the last mode used; press both arrow keys simultaneously to toggle modes.
2. Adjust Temperature: Press up/down arrows to set the desired temperature. “Low” displays for first-stage heat/cool; “High” displays for second-stage (if applicable).
3. Fan Control: Press FAN to select AUTO (runs only when heating/cooling) or ON (continuous).
4. Manual Override: Press HOLD and adjust temperature to bypass any schedule until RUN SCHEDULE is pressed. In non-programmable mode (set to 0 days in Configuration Menu), the thermostat maintains the set temperature indefinitely.

Operating in Programmable Mode

1. Factory Schedule: The thermostat is pre-programmed with energy-saving settings (e.g., Heat: 70°F day, 62°F night; Cool: 78°F day, 82°F night). Press RUN SCHEDULE to use defaults.
2. Custom Schedule:

Press MENU, then select SET SCHEDULE, and choose HEAT or COOL.
Select 7-day programming (individual days).
Set times/temperatures for Morning, Day, Evening, Night periods for each day using up/down arrows.
Save by pressing RUN SCHEDULE.

3. Temporary Override: Press up/down arrows to adjust temperature temporarily until the next period; “Hold At” displays to the left of the setpoint.
4. Permanent Hold: Press HOLD and adjust temperature to maintain it until RUN SCHEDULE is pressed; “Hold At” displays.
5. Disable Programming: Press MENU, hold Thermostat Options Configuration Menu for 5 seconds, and set program days to 0 (non-programmable).

Advanced Features

1. Temperature Offset: Adjust in Configuration Menu (scrolling message “TEMPERATURE ADJUSTMENT”) to calibrate display temperature (±5°F) to match a previous thermostat.
2. Maintenance Reminder: Displays in the scrolling message area for accessory maintenance (e.g., filter, humidifier pad) if enabled in Configuration Menu. Clear by pressing the Clean Display key, resetting the timer.
3. Keypad Lockout: Enable in Configuration Menu with a PIN (000-999); unlock by entering the PIN when prompted.
4. Fast Stages: Enable in Configuration Menu (scrolling message “FAST STAGES”) to engage all heat/cool stages when setpoint is changed by 3°F or more.
5. System Problem Detection: Displays “Call for Service” and “CHECK CROSSOVER” if a system fault is detected; clears when corrected. Contact a qualified technician if persistent.
6. Continuous Backlight: Enable in Configuration Menu for constant display lighting (requires C wire).

Troubleshooting

No Display: Check battery polarity or replace with fresh AA alkaline batteries. Verify C wire connection for hardwired setups. Reset by pressing SYSTEM and up/down arrows simultaneously until the display blanks; settings revert to factory defaults.
No Heat/Cool: Ensure SYSTEM is set to HEAT/COOL/EM, setpoint is above/below room temperature, and circuit breaker is on. Check for compressor delay (up to 5 minutes). Verify wiring and system configuration. If “Call for Service” displays, contact a technician.
System Runs Continuously: Set SYSTEM to HEAT or COOL (not AUTO) and FAN to AUTO. Check setpoint settings. Verify no shorted wires or incorrect configuration.
Inaccurate Temperature: Adjust temperature offset in Configuration Menu (±5°F). Ensure thermostat is not near drafts, heat sources, or exterior walls.
Maintenance Reminder Persists: Clear by pressing Clean Display key when the reminder appears in the scrolling message area.
Erratic Operation: Reset by pressing SYSTEM and up/down arrows simultaneously. If issues persist, remove batteries for 2 minutes and reinsert. If the display remains blank or erratic, contact a professional technician.

Installation Instructions

Warning: Thermostat installation and all components of the control system shall conform to Class II circuits per the NEC code. Direct wiring to the furnace board is required; homeowner installation is not recommended. Disconnect power at the main fuse or circuit breaker before installation to prevent electrical shock or equipment damage.

Remove Old Thermostat

Before removing wires, mark wires for terminal identification to ensure proper connections to the new thermostat. Take a picture of the wiring for reference.

Installing New Thermostat

Pull the thermostat body off the thermostat base. Do not force or pry to avoid damage.
Place base over the hole in the wall and mark mounting hole locations using the base as a template.
Move base out of the way, drill mounting holes. Use plastic screw anchors if existing holes are too large.
Fasten base snugly to the wall using mounting holes and two mounting screws. Leveling is for appearance only and does not affect operation.
Connect wires to the terminal block on the base using the appropriate wiring schematic. Ensure direct wiring to the furnace board as per system requirements.
Push excess wire into the wall and plug the hole with fire-resistant material (e.g., fiberglass insulation) to prevent drafts.
Carefully line the thermostat up with the base and snap into place.

Battery Location

Includes 2 AA alkaline batteries at the factory with a battery tag to prevent power drainage. Remove the tag to engage batteries.
To replace, set system to OFF, remove thermostat from the wall, and install batteries in the rear along the top. Use premium brand AA alkaline batteries like Duracell or Energizer.
If the home will be unoccupied for over 3 months and the battery level indicator shows low, replace batteries before leaving.

Power Stealing Switches

Leave switches in the “On” position for most systems. Details in the following table:

Thermostat Power Method	Switch Position/Description
Battery Powered, no 24 Volt system	Switches “On”, thermostat runs on batteries.
Hardwired with Battery Back-up, for 24 Volt systems with common connection from transformer to “C” terminal	Switches “On”, thermostat runs on power directly from transformer with battery back-up.
Battery Powered with Power Stealing Assist, for 24 Volt systems with no common connection	Switches “On”, thermostat runs on batteries and supplemental power drawn through heat or cool circuit.

Caution: Power Stealing Assist may cause issues on systems with high impedance electronic modules (e.g., furnace draft inducer motor running with no call for heat, furnace fan not turning off). If incompatible, set switches to “Off” to operate on batteries.