PRO 3000 Thermostat TH3110D1008

Honeywell Home PRO 3000 TH3110D1008

The Honeywell Home PRO 3000 Series is a line of non-programmable digital thermostats designed to control compatible heating and cooling systems. The installation instructions cover models TH3110D1008 and TH3210D1004, including wallplate mounting, electrical wiring, power options, installer settings, system testing, and troubleshooting.

The TH3110D1008 supports single-stage heating and cooling configurations, including compatible 1H/1C heat pump systems. The TH3210D1004 is designed for 2H/1C heat pump installations with auxiliary and emergency heating controls.

Both thermostats provide digital temperature adjustment, heating and cooling operation, and compressor protection. The devices can use AA alkaline batteries for primary or backup power, with an optional 24 VAC common-wire connection.

Important: Disconnect electrical power before installing or wiring the thermostat. Incorrect electrical connections may cause electric shock or equipment damage. Installation and system configuration should be completed by a qualified HVAC technician.

Product Overview

The Honeywell PRO 3000 Series provides direct temperature control without requiring a programmable heating or cooling schedule.

Users can select the desired operating mode using the System switch and change the temperature setting using the Up and Down buttons.

The thermostat also includes installer configuration functions that allow its heating cycle rate, compressor cycle rate, temperature display, and compressor protection settings to be matched to the connected equipment.

Main Features

• Non-programmable temperature control: Adjusts heating and cooling setpoints manually.
• Digital temperature display: Shows indoor temperature and operating status.
• Heat and Cool operation: Controls compatible heating and cooling equipment.
• Emergency Heat: Available on the TH3210D model.
• Fan control: Provides automatic and continuous fan operation.
• Multiple power options: Supports AA alkaline batteries and 24 VAC common-wire power.
• Single-transformer and two-transformer wiring: Supported on the TH3110D.
• Heat pump compatibility: Supports the heat pump configurations specified for each model.
• Adjustable heating cycle rate: Configures heating cycles per hour.
• Compressor cycle rate: Provides multiple cycle-rate options.
• Fahrenheit and Celsius: Allows the temperature display unit to be selected.
• Compressor protection: Delays compressor restarting to help prevent equipment damage.
• Installer system test: Allows heating, cooling, and emergency heat operation to be checked.
• Troubleshooting indicators: Displays Heat On and Cool On messages during operating conditions.

Honeywell PRO 3000 Models

The installation instructions cover two models with different heating capabilities and terminal configurations.

TH3110D1008

The TH3110D1008 supports these wiring configurations:

• 1H/1C conventional heating and cooling with one transformer.
• 1H/1C conventional heating and cooling with two transformers.
• 1H/1C heat pump.
• Heat-only.
• Heat-only with fan.
• Cool-only.

TH3210D1004

The TH3210D1004 supports a 2H/1C heat pump system.

Its additional terminals provide connections for auxiliary heat, emergency heat, and an emergency heat output.

Technical Specifications

Parts and Components

The Honeywell PRO 3000 thermostat consists of a thermostat body, digital display, temperature adjustment buttons, System and Fan switches, and a removable wallplate with electrical terminals.

Digital Display

The thermostat display shows indoor temperature information and heating or cooling status.

During installer setup, the screen displays a function number and its selected setting.

During system testing, it displays the test number and system status.

Temperature Adjustment Buttons

The Up and Down buttons are used to change the selected temperature.

They are also used to enter Installer Setup, change configuration values, and test the connected equipment.

System Switch

The System switch selects the operating mode.

The TH3210D includes an additional Emergency Heat position.

Fan Switch

The Fan switch provides two standard operating settings:

• Auto: The fan operates according to the connected heating or cooling equipment.
• On: The fan runs continuously.

Thermostat Controls and Display Guide

System Switch Settings

Fan Switch Settings

Temperature Adjustment Buttons

Display Messages

Important Safety Instructions

The thermostat controls electrical heating and cooling equipment. Installation and testing must follow the manufacturer’s electrical and equipment precautions.

Electrical Safety

Caution: Electrical hazard.

Electrical contact during installation may cause shock or equipment damage.

• Disconnect power before beginning installation.
• Do not work on energized thermostat wiring.
• Follow the electrical ratings for the connected equipment.
• Provide the required electrical disconnect and overload protection.
• Use the terminal connections specified for the HVAC configuration.
• Do not remove the factory R/Rc jumper unless installing a two-transformer system.
• Use the correct common-wire connection when installing a two-transformer system.
• Secure the wiring connections before mounting the thermostat.
• Have electrical installation and equipment testing performed by a qualified technician.

Compressor Protection Warning

Caution: Equipment damage hazard.

Compressor protection is bypassed during installer system testing.

Rapidly switching the compressor on and off may damage the equipment.

Avoid repeated compressor cycling while testing heating or cooling operation.

Mercury Disposal Notice

If the thermostat replaces an older control containing mercury in a sealed tube, the old thermostat must not be placed in ordinary household trash.

Contact the local waste management authority for recycling and disposal instructions.

Electronic Waste Disposal

The thermostat must not be disposed of with ordinary household waste.

Use an authorized collection center or electronics recycler when the product reaches the end of its usable life.

Before Installation

Before mounting the Honeywell PRO 3000 thermostat, identify the HVAC equipment, existing thermostat wiring, and required power connection.

Installation Preparation

1. Turn off electrical power to the heating and cooling equipment.
2. Identify the thermostat model being installed.
3. Determine whether the equipment uses conventional heating and cooling or a heat pump.
4. Identify the number of transformers in the system.
5. Identify the thermostat wires and their required terminal connections.
6. Determine whether battery or 24 VAC common-wire power will be used.
7. Prepare the wallplate and mounting hardware.
8. Confirm the required fan operation setting.
9. Keep the appropriate wiring configuration available for reference during installation.

Thermostat Wire Requirements

Use 18- to 22-gauge thermostat wire.

Shielded cable is not required.

Wallplate Installation Instructions

The thermostat body must be separated from its wallplate before installation.

Step 1: Remove the Wallplate

1. Hold the thermostat securely.
2. Locate the bottom of the wallplate.
3. Pull the wallplate away from the thermostat body from the bottom.
4. Separate the wallplate.

Step 2: Position the Wallplate

1. Pull the thermostat wires through the wallplate’s central opening.
2. Position the wallplate against the wall.
3. Level the wallplate.
4. Mark the mounting hole positions with a pencil.

Step 3: Drill the Mounting Holes

Use the drill bit size appropriate for the wall material.

1. 
   Drill the marked holes.
2. Insert the supplied wall anchors.
3. Tap the anchors into position.

Step 4: Secure the Wallplate

1. Position the wallplate over the wall anchors.
2. Insert the mounting screws.
3. Tighten the screws.
4. Check that the wallplate is properly secured.

The thermostat wiring can now be connected.

Power Options and Battery Installation

The Honeywell PRO 3000 thermostat supports battery power and a 24 VAC common-wire connection.

Available Power Methods

How to Install AA Batteries

1. Separate the thermostat body from the wallplate.
2. Locate the battery compartment on the back of the thermostat.
3. Insert fresh AA alkaline batteries.
4. Follow the polarity markings in the compartment.
5. Check that the batteries are correctly seated.

The installation guide identifies AA alkaline batteries for primary or backup power.

Using the C Terminal for AC Power

The C terminal provides a 24 VAC common-wire connection.

This connection is optional when batteries are installed.

For a two-transformer TH3110D system, the common connection must come from the cooling transformer.

R and Rc Jumper

The TH3110D has a factory-installed jumper between the R and Rc terminals.

Important: Remove the factory-installed jumper only for a two-transformer system.

Honeywell TH3110D1008 Wiring Instructions

The TH3110D1008 uses eight thermostat terminals for supported heating, cooling, fan, and heat pump connections.

TH3110D Wiring Terminal Designations

TH3110D 1H/1C Conventional System With One Transformer

A single-transformer heating and cooling system uses the following terminals.

The factory R/Rc jumper remains installed.

TH3110D 1H/1C Conventional System With Two Transformers

For separate heating and cooling transformers:

Important: Remove the R/Rc jumper when using two transformers.

The optional C terminal connection must come from the cooling transformer.

TH3110D 1H/1C Heat Pump System

The TH3110D also supports a single-stage heat pump.

Use either O or B according to the heat pump’s changeover valve requirements.

A short wire, not supplied, must connect the W and Y terminals.

The installer must also:

1. Set the fan operation switch to Electric or Heat Pump.
2. Configure Installer Setup Function 1 for a heat pump.

TH3110D Heat-Only System

TH3110D Heat-Only System With Fan

TH3110D Cool-Only System

Honeywell TH3210D1004 Wiring Instructions

The TH3210D1004 supports a two-heat, one-cool heat pump system with auxiliary and emergency heat connections.

TH3210D Wiring Terminals

TH3210D 2H/1C Heat Pump Configuration

The wiring arrangement includes:

• R for the power supply.
• C for the optional 24 VAC common connection.
• G for the fan relay.
• Y for the compressor contactor.
• O or B for the changeover valve.
• Aux for auxiliary heat.
• E for emergency heat.
• L for the emergency heat output signal.

TH3210D Heat Pump Wiring Notes

Changeover Valve: Use either O or B according to the connected equipment.

L Terminal: Sends a continuous output when the thermostat is set to Emergency Heat. The output can be connected to compatible Honeywell Home zoning panels to switch the panel to Emergency Heat.

Aux and E Terminals: Install a field jumper between Aux and E if the system has no emergency heat relay.

Electrical Protection: Provide the required disconnect means and overload protection for the power supply.

These terminal arrangements must match the actual heat pump and heating equipment.

TH3110D Fan Operation Switch Settings

The TH3110D has an internal fan operation switch.

This switch determines whether the heating equipment or thermostat controls the fan during a heating call.

Gas or Oil Heating

For gas or oil systems:

• Leave the fan operation switch in the factory-set Gas or Oil position.

This setting is intended for heating equipment that controls the fan during a call for heat.

Electric Heating or Heat Pump

For electric heating or heat pump systems:

1. Locate the fan operation switch.
2. Set it to Electric or Heat Pump.
3. Confirm that the system has the appropriate fan connection to the G terminal.

This setting is intended for systems that allow the thermostat to control the fan during heating.

Fan Operation Settings Summary

Mounting the Thermostat

After wiring and fan configuration are complete, attach the thermostat body to the installed wallplate.

Installation Steps

1. Identify the four tabs on the wallplate.
2. Align them with the matching slots on the back of the thermostat.
3. Push the thermostat gently until it snaps into place.
4. Push excess wiring back into the wall opening.
5. Plug the wall opening using nonflammable insulation.

The thermostat must be securely attached before proceeding with system configuration and testing.

Installer Setup Instructions

The Installer Setup menu allows the thermostat to be configured according to the connected HVAC equipment.

How to Enter Installer Setup

1. Locate the Up and Down temperature buttons.
2. Press and hold both buttons simultaneously.
3. Continue holding until the display changes.
4. The screen will show a function number and selected setting.

Installer Setup Button Functions

Installer Setup Function 1: System Type

Applicable model: TH3110D1008.

Function 1 selects the HVAC system type.

Selecting Heat Pump provides a five-minute compressor off time during heating and cooling.

Installer Setup Function 5: Heating Cycle Rate

Applicable model: TH3110D1008.

Function 5 controls heating cycles per hour.

CPH means cycles per hour.

Additional selectable values include:

2, 4, 6, 7, 8, 10, 11, and 12 CPH.

The setting should match the heating equipment.

Installer Setup Function 6: Auxiliary Heat Cycle Rate

Applicable model: TH3210D1004.

Function 6 controls auxiliary heating cycles per hour.

Additional settings include:

2, 4, 6, 7, 8, 10, 11, and 12 CPH.

Installer Setup Function 8: Emergency Heat Cycle Rate

Applicable model: TH3210D1004.

Function 8 controls emergency heating cycles per hour.

Additional settings include:

2, 4, 6, 7, 8, 10, 11, and 12 CPH.

Installer Setup Function 9: Compressor Cycle Rate

Function 9 controls the compressor cycle rate.

Other available settings:

1, 2, 4, 5, and 6 CPH.

The recommended setting for most compressors is 3 cycles per hour.

Installer Setup Function 14: Temperature Display

Function 14 changes the thermostat temperature display between Fahrenheit and Celsius.

How to Change Fahrenheit to Celsius

1. Enter Installer Setup.
2. Advance to Function 14 using the Up button.
3. Press the Down button to select 1.
4. Press and hold both temperature buttons to save and exit.

To return to Fahrenheit, select setting 0.

Installer Setup Function 15: Compressor Protection

Function 15 controls the minimum time that the compressor must remain off before restarting.

The feature helps prevent damage from rapid restarting.

The factory setting is 5 minutes.

How Compressor Protection Works

When the compressor shuts down, the thermostat may delay restarting it.

During the waiting period:

• Cool On flashes for cooling operation.
• Heat On may flash for heat pump operation.
• The compressor remains off until the protection interval ends.

Once the delay finishes, the system can restart.

Why Cool On or Heat On Flashes

A flashing message usually indicates compressor protection is active.

When the five-minute protection setting is used, wait five minutes before expecting the compressor to restart.

Do not repeatedly cycle the system to bypass the delay.

Installer System Test

The Installer System Test verifies that the thermostat is controlling the connected heating and cooling equipment correctly.

Caution: Compressor protection is bypassed during testing. Avoid rapid compressor cycling.

How to Run the Installer Test

1. Set the System switch to Heat.
2. Use the Down button to activate the system test.
3. Check the heating operation.
4. Press Down until the system turns off.
5. For TH3210D, move the System switch to Em Heat and repeat the test.
6. Set the System switch to Cool.
7. Repeat the test procedure for cooling.
8. Press and hold the Up and Down buttons together to terminate the test.

Heating System Test Codes

System Test 10

Emergency Heat System Test Codes

System Test 20

Applicable model: TH3210D1004.

Cooling System Test Codes

System Test 30

Thermostat Information Codes

System Test 70

Test 70 displays thermostat information for reference.

These values identify the thermostat’s software and configuration information.

Operating Instructions

After installation and testing are complete, the thermostat can be used to control the connected system.

How to Turn On Heating

1. Move the System switch to Heat.
2. Use the Up button to select a temperature higher than the current indoor temperature.
3. Allow the heating system to respond.

How to Turn On Cooling

1. Move the System switch to Cool.
2. Use the Down button to select a temperature lower than the current indoor temperature.
3. Allow the cooling system to respond.

The equipment may require several minutes to respond because of compressor protection.

How to Turn Off Heating and Cooling

Move the System switch to Off.

How to Use Emergency Heat

Applicable model: TH3210D1004.

Move the System switch to Em Heat to select emergency heat operation.

The emergency heat wiring and installer configuration must match the connected equipment.

How to Run the Fan Continuously

Move the Fan switch to On.

How to Use Automatic Fan Operation

Move the Fan switch to Auto.

The connected equipment will control fan operation according to its heating or cooling requirements.

Heating and Cooling Temperature Settings

The Honeywell PRO 3000 has separate permitted temperature ranges for heating and cooling.

Adjusting the Heating Temperature

1. Set the System switch to Heat.
2. Press Up or Down.
3. Select a temperature within the heating range.

Adjusting the Cooling Temperature

1. Set the System switch to Cool.
2. Press Up or Down.
3. Select a temperature within the cooling range.

If the selected setting does not change, check that it is within the allowed temperature range.

Battery Maintenance

The thermostat uses AA alkaline batteries for primary or backup power.

Battery Replacement

1. Disconnect power before removing the thermostat for installation or servicing work.
2. Pull the bottom of the thermostat away from the wallplate.
3. Locate the battery compartment on the back.
4. Remove the used batteries.
5. Insert fresh AA alkaline batteries.
6. Check the battery polarity.
7. Reattach the thermostat to the wallplate.

Battery Installation Checks

If the display is blank, confirm that fresh AA alkaline batteries are installed correctly.

Also check the circuit breaker, heating and cooling equipment power switch, and furnace door.

Troubleshooting Guide

The following problems and corrective actions are provided for the Honeywell PRO 3000 thermostats.

Honeywell TH3110D1008 Blank Display

If the thermostat display is blank:

1. Check the circuit breaker.
2. Reset the breaker if necessary.
3. Confirm that the heating and cooling equipment power switch is on.
4. Make sure the furnace door is securely closed.
5. Check that fresh AA alkaline batteries are installed correctly.

Honeywell PRO 3000 Heat Not Working

If the heating system does not respond:

1. Move the System switch to Heat.
2. Check the Inside temperature displayed by the thermostat.
3. Set the desired temperature higher than the current indoor temperature.
4. Wait five minutes for the system to respond.

If the equipment still does not operate, have the connected system and installation inspected by a qualified technician.

Honeywell PRO 3000 Cooling Not Working

If the cooling system does not respond:

1. Set the System switch to Cool.
2. Check the current indoor temperature.
3. Select a cooling temperature lower than the current indoor temperature.
4. Wait five minutes.

The compressor protection feature may delay cooling operation.

Honeywell Thermostat Temperature Not Changing

If the temperature setting cannot be adjusted, verify that the requested value is within the allowed range.

The thermostat does not permit settings outside these ranges.

Honeywell Thermostat Cool On Flashing

A flashing Cool On message indicates that compressor protection is active.

The recommended protection interval is five minutes.

Wait for the delay to finish before expecting the compressor to restart.

Honeywell Thermostat Heat On Flashing

On a heat pump system, a flashing Heat On message may indicate compressor protection.

Wait five minutes when the factory protection setting is used.

The compressor is allowed to restart after the waiting period ends.

Honeywell Thermostat Heat On Not Displayed

If Heat On does not appear:

1. Set the System switch to Heat.
2. Set the desired temperature above the current indoor temperature.

Honeywell Thermostat Cool On Not Displayed

If Cool On does not appear:

1. Set the System switch to Cool.
2. Set the desired temperature below the current indoor temperature.

Model Number and Date Code Identification

The model number and date code are located on the back of the thermostat.

How to Find the Model Number

1. Disconnect power before removing the thermostat for service.
2. Pull the bottom of the thermostat away from the wallplate.
3. Turn the thermostat over.
4. Locate the model number and date code on the back.

The information can be used when contacting customer support or arranging service.

Customer Support Information

The Honeywell Home PRO 3000 Series is manufactured by Resideo Technologies, Inc. and its affiliates under license from Honeywell International Inc.

For assistance with thermostat operation, installation questions, or unresolved system problems, contact Resideo Customer Care.

Frequently Asked Questions

How do I install the Honeywell TH3110D1008 thermostat?

Disconnect electrical power before installation. Remove the thermostat from its wallplate, pull the thermostat wires through the mounting opening, level and secure the wallplate, and connect the wires according to the HVAC system. Set the internal fan operation switch, install batteries if required, attach the thermostat, and complete installer setup and system testing. Electrical wiring and testing should be performed by a qualified HVAC technician.

What is the Honeywell TH3110D1008 wiring diagram?

The TH3110D1008 uses C, B, R, Rc, O, G, Y, and W terminals. It supports conventional 1H/1C systems with one or two transformers, 1H/1C heat pumps, heat-only systems, heat-only systems with a fan, and cool-only systems. The exact connections depend on the equipment. The R/Rc jumper is removed only for two-transformer systems.

How do I change the Honeywell PRO 3000 from Fahrenheit to Celsius?

Press and hold the Up and Down temperature buttons to enter Installer Setup. Advance to Function 14 using the Up button. Press Down to select setting 1 for Celsius or setting 0 for Fahrenheit. Press and hold both buttons to save and exit.

Why is Cool On flashing on my Honeywell TH3110D1008?

Cool On flashes when compressor protection is active. The thermostat delays restarting the compressor to prevent equipment damage. The factory setting is five minutes, so the system may require approximately five minutes before cooling resumes.

What batteries does the Honeywell PRO 3000 thermostat use?

The thermostat uses AA alkaline batteries. They can provide primary power or backup power when a 24 VAC common-wire connection is installed. If the display becomes blank, check that fresh batteries are installed correctly.

Why is my Honeywell PRO 3000 thermostat not heating?

Check that the System switch is set to Heat and the selected temperature is higher than the current indoor temperature. Wait five minutes for the system to respond. If heating still does not operate, the connected HVAC equipment should be inspected by a qualified technician.

What is the difference between Honeywell TH3110D1008 and TH3210D1004?

The TH3110D1008 supports single-stage heating and cooling configurations, including a compatible 1H/1C heat pump. The TH3210D1004 supports a 2H/1C heat pump with auxiliary and emergency heat controls. The TH3210D includes Aux, E, and L terminals for these additional functions.