Emerson 1F75P-21PR Thermostat Operation Manual

The Emerson 1F75P-21PR is a programmable thermostat designed for single-stage cooling and one or two stage heating systems, offering easy-to-use features and energy-saving programming. It is suitable for electric only systems with auxiliary heat. Below are the key specifications and operation instructions.

Key Specifications

• Type: Programmable thermostat for single-stage cooling and one or two stage heating
• Compatibility:
  • Electric only systems
  • One stage auxiliary heat
  • Not compatible with systems exceeding 30 VAC
• Power Source:
  • Battery: 20 to 30 VAC, NEC Class II, 50/60 Hz
  • Input-Hardwire: 20 to 30 VAC, NEC Class II, 50/60 Hz
• Electrical Rating:
  • Terminal Load: 1.5 A per terminal, 2.5A maximum all terminals combined
  • Rated Differentials (@ 6°F/Hr): Heat Pump (Heating): 0.9°F (Fast), 1.2°F (Med), 1.7°F (Slow); Heat Pump (Cooling): 0.9°F (Fast), 1.2°F (Med), 1.7°F (Slow); Auxiliary Heat: 0.5°F (Fast), 0.75°F (Med), 1.9°F (Slow)
• Temperature Range: Setpoint 60° to 85° F (16° to 29° C); Display Temperature Range: 32°F to +99°F (0 to 37°C)
• Operating Conditions:
  • Ambient: 32°F to +105°F (0° to +41°C)
  • Humidity: 90% non-condensing maximum
  • Shipping: -20°F to +150°F (-29° to +65°C)
• Dimensions: 3-3/4" H x 6" W x 1-1/8" D
• Features:
  • Programmable scheduling
  • Automatic heat/cool changeover
  • Compressor protection
  • Keypad lockout
  • Energy-saving pre-programmed schedules
• Thermostat Configuration Options:
  • Single Stage Cooling, One or Two Stage Heating – 1 Stage Aux Heat
  • Electric only
  • Maximum Stages Heat/Cool: 2/1

Operation Instructions

Initial Setup

1. Insert Batteries: Install 2 AA alkaline batteries in the rear compartment. Replace when the battery indicator shows low.
2. Power On: If hardwired, ensure 20-30 VAC is supplied. The display should show the home screen.
3. Configure System:

• Hold MENU for 8 seconds to access INSTALLER MENU.
• Select system type, fan settings, and other options.
• Exit by pressing RUN.

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 to save and exit.

Operating in Non-Programmable Mode

1. Select Mode: Press SYSTEM to choose HEAT, COOL, AUTO, or OFF.
2. Adjust Temperature: Press up/down arrows to set the desired temperature.
3. Fan Control: Press FAN to select AUTO or ON.
4. Manual Override: Press HOLD to set a constant temperature.

Operating in Programmable Mode

1. Factory Schedule: Pre-programmed with energy-saving settings.
2. Custom Schedule:

• Press MENU, then Program.
• Set times/temperatures for periods.
• Save by pressing RUN.

3. Temporary Override: Adjust temperature with up/down arrows.
4. Permanent Hold: Press HOLD to maintain temperature.
5. Disable Programming: Set in INSTALLER MENU.

Advanced Features

1. Humidity Control: Configure in INSTALLER MENU if compatible equipment is installed.
2. Dual Fuel: Set balance point for optimization.
3. Keypad Lockout: Enable to restrict access.

Troubleshooting

• No Display: Check batteries or connections.
  
• No Heat/Cool: Ensure settings and wiring are correct.
  
• System Runs Continuously: Verify mode and fan settings.

Installation Instructions

Warning: Conform to Class II circuits per the NEC code.

Remove Old Thermostat

• Mark wires for terminal identification.

Installing New Thermostat

1. Pull body off base.
2. Mark mounting holes.
3. Drill holes.
4. Fasten base.
5. Connect wires.
6. Push excess wire into wall.
7. Snap onto base.

Battery Location

• Install 2 AA batteries.
• Replace when low.

Power Stealing Switches

Leave in "On" for most systems.

Thermostat Power Method	Switch Position/Description
Battery Powered, no 24 Volt system	Switches "On", thermostat runs on batteries.
Hardwired with Battery Back-up	Switches "On", runs on power from transformer with battery back-up.
Battery Powered with Power Stealing Assist	Switches "On", runs on batteries and supplemental power.

Caution: May cause issues on high impedance systems. Set to "Off" if incompatible.