Honeywell TH1110D2009 Manual: A Comprehensive Guide
This manual details the Honeywell TH1110D2009/U T1 Pro thermostat, a non-programmable device for 24 Vac systems. It covers installation, operation, and troubleshooting,
specifically for single-stage heating and cooling, including heat pumps without auxiliary heat.
Overview of the Honeywell TH1110D2009 Thermostat
The Honeywell TH1110D2009/U is a T1 Pro Series non-programmable thermostat designed for straightforward control of home heating and cooling systems. Manufactured by Resideo Technologies, Inc. under license from Honeywell International, Inc., this thermostat is ideal for 24 Vac systems.
It supports single-stage heating and cooling configurations, and is also compatible with single-stage heat pump systems without auxiliary heat. The thermostat features simple, push-button controls for easy temperature adjustments and system mode selection.
Importantly, due to local regulations, as of January 1, 2026, this product is not available for sale within the state of Colorado. It is exclusively available for purchase and use within the United States. This thermostat offers a reliable and user-friendly solution for maintaining comfortable indoor temperatures.
Key Features and Specifications
The Honeywell TH1110D2009/U boasts several key features, including easy installation and simple push-button operation. It’s designed for 24 Vac systems and supports single-stage heating and cooling applications. Compatibility extends to single-stage heat pumps, but without auxiliary heat functionality.
Regarding specifications, the thermostat requires two AA batteries for power. It’s a non-programmable model, offering consistent temperature control without scheduling complexities. The device includes mounting hardware – screws and wall anchors – for secure installation.
A crucial note: sales are restricted in Colorado starting January 1, 2026, due to local regulations; This thermostat is exclusively available within the US market. Its compact design and straightforward interface make it a practical choice for residential and light commercial settings.
Target Applications: Residential and Commercial Settings
The Honeywell TH1110D2009/U thermostat is ideally suited for a broad range of applications, primarily within residential and light commercial environments. Its simple operation and reliable performance make it a popular choice for homeowners seeking straightforward temperature control.
Specifically, it excels in spaces utilizing 24 Vac heating and cooling systems, including those with single-stage furnaces and air conditioners. The thermostat’s compatibility with single-stage heat pumps (without auxiliary heat) further expands its usability.
Small businesses, rental properties, and individual homes benefit from its ease of use and installation. However, it’s important to remember the sales restriction in Colorado after January 1, 2026. The thermostat’s US-only availability also limits its application geographically.
Installation Guide
This section provides step-by-step instructions for installing the Honeywell TH1110D2009/U thermostat, detailing required tools, wiring diagrams, and mounting procedures for 24 Vac systems.
Package Contents: What’s Included
Upon opening the Honeywell TH1110D2009/U package, you should find all the necessary components for a standard installation. The kit includes the thermostat itself, designed for simple push-button control of your heating and cooling system. You will also receive two AA batteries, essential for powering the thermostat’s operation.
Furthermore, the package contains screws and wall anchors, facilitating secure mounting of the thermostat base plate. Crucially, the documentation for the TH1110D2009, TH1010D2000 thermostats is included – please read this thoroughly before beginning installation. An optional cover plate is also provided; however, installation instructions for the UWP mounting system are separate if the cover plate isn’t needed. Ensure all listed items are present before proceeding.
Required Tools for Installation
To ensure a smooth and successful installation of your Honeywell TH1110D2009/U thermostat, gathering the correct tools beforehand is crucial. A Phillips head screwdriver is essential for securing the base plate and connecting the wiring. A small, flathead screwdriver may also be useful for certain terminal connections.
Depending on your wall material, you might need a drill with appropriately sized drill bits to create pilot holes for the mounting screws and wall anchors. Wire strippers are necessary for preparing the thermostat wires, ensuring clean and reliable connections. A level will help guarantee the thermostat is mounted straight for aesthetic appeal and accurate readings. Finally, a voltage tester is highly recommended to verify power is off before working with any wiring.
Mounting the Thermostat Base Plate
Before mounting, ensure power to the heating and cooling system is completely switched off at the breaker. Carefully remove your old thermostat, noting the wire connections. Use the provided mounting screws and wall anchors to securely attach the Honeywell TH1110D2009/U base plate to the wall.
Utilize a level to confirm the base plate is straight. If using the optional cover plate, install it now. Feed the thermostat wires through the opening in the base plate. Ensure sufficient wire length is available for easy connection to the terminals. Double-check that the base plate is firmly mounted and won’t wobble before proceeding to the wiring stage. Proper mounting is vital for stable operation.
Wiring Diagram: 24 Vac Systems
The Honeywell TH1110D2009/U thermostat is designed for standard 24 Vac heating and cooling systems. Refer to the wiring diagram included in the product documentation for precise terminal connections. Typically, you’ll connect wires labeled R (power), W (heat), Y (cool), and C (common).
Carefully match the wire labels from your existing thermostat to the corresponding terminals on the Honeywell base plate; Ensure each wire is securely inserted into the terminal block. Incorrect wiring can damage the thermostat or your HVAC system. If unsure, consult a qualified HVAC technician. A properly wired connection is crucial for safe and efficient operation.
Connecting to Single-Stage Heat and Cool Systems
For single-stage heating and cooling systems, the Honeywell TH1110D2009/U utilizes a straightforward wiring configuration. Connect the R wire to the Rh terminal for heating power and Rc for cooling power (jumper if combined). The W wire connects to the W1 terminal for heat activation, and the Y wire connects to the Y1 terminal for cooling activation.
The common (C) wire provides continuous power to the thermostat. Ensure all connections are secure. After wiring, power on the HVAC system and verify proper operation in both heating and cooling modes. If the system doesn’t respond correctly, double-check the wiring against the diagram and consult a professional if needed.
Heat Pump Compatibility (Without Auxiliary Heat)
The Honeywell TH1110D2009/U thermostat is compatible with single-stage heat pump systems that do not utilize auxiliary heat. Wiring differs slightly from conventional systems. Connect the R wire to Rh, and the C wire to the common terminal for consistent power. The heat pump’s reversing valve control wire (O/B) connects to the O/B terminal – configuration depends on the heat pump’s wiring (check manufacturer’s instructions).
The Y wire activates cooling, and W1 activates heating. Verify the O/B wire setting is correct for your system to ensure proper heating and cooling cycles. Incorrect wiring can lead to reversed operation. Always consult the heat pump’s documentation and a qualified technician if unsure.
Operation and Programming
The Honeywell TH1110D2009 features simple, push-button control for temperature setting, system mode selection (heat, cool, off), and fan operation adjustments.
Basic Button Controls and Functions
The Honeywell TH1110D2009 thermostat utilizes a straightforward interface with intuitive button controls. The primary buttons allow users to easily adjust the set temperature, increasing or decreasing it as needed for desired comfort levels. A dedicated ‘Mode’ button cycles through the available system modes: Heat, Cool, and Off. Selecting ‘Heat’ activates the heating system, while ‘Cool’ engages the cooling system. The ‘Off’ mode disables both, allowing for manual control or ventilation.
The ‘Fan’ button controls the fan operation, offering options like ‘Auto’ – where the fan runs only during heating or cooling cycles – and ‘On’ – for continuous fan operation. These simple controls ensure ease of use for all users, providing direct access to essential thermostat functions without complex programming. The thermostat’s design prioritizes simplicity and accessibility.
Setting the Temperature
To adjust the desired room temperature on the Honeywell TH1110D2009 thermostat, utilize the Up and Down arrow buttons located on the control panel. Each press of these buttons will incrementally increase or decrease the set temperature by one degree. The current set temperature is prominently displayed on the thermostat’s screen, providing a clear visual reference.
The thermostat responds immediately to button presses, allowing for precise temperature adjustments. Users can continue pressing the buttons until the desired temperature is reached. The system will then automatically activate the heating or cooling system to maintain the set temperature. This simple process ensures comfortable and consistent climate control within the space. Remember to allow sufficient time for the system to respond to temperature changes.
System Mode Selection (Heat, Cool, Off)
The Honeywell TH1110D2009 thermostat offers three primary system modes: Heat, Cool, and Off. To cycle through these modes, use the “Mode” button on the control panel. Each press will advance the thermostat to the next available mode. The currently selected mode is clearly indicated on the display screen, ensuring easy identification.
In “Heat” mode, the thermostat activates the heating system when the room temperature falls below the setpoint. “Cool” mode activates the cooling system when the temperature rises above the setpoint. Selecting “Off” disables both heating and cooling, allowing for manual control or ventilation. This straightforward mode selection process allows users to easily adapt the thermostat to changing weather conditions and personal preferences, optimizing comfort and energy efficiency.
Fan Control Options
The Honeywell TH1110D2009 thermostat provides several fan control options to enhance comfort and air circulation. Users can select “Auto” mode, where the fan operates only during heating or cooling cycles, optimizing energy usage. Alternatively, the “On” mode keeps the fan running continuously, providing consistent air movement and potentially improving air quality.
To adjust the fan setting, utilize the designated “Fan” button on the thermostat’s interface. Each press cycles through the available options. The selected mode is visibly displayed on the screen. Continuous fan operation can help distribute air more evenly throughout the space, reducing temperature fluctuations. Selecting the appropriate fan mode allows users to tailor the system to their specific needs and preferences.
Troubleshooting
This section details common issues, solutions, and error codes for the Honeywell TH1110D2009 thermostat, alongside instructions for battery replacement to ensure optimal performance.
Common Issues and Solutions
Issue: Thermostat displays no power. Solution: First, verify the batteries are fresh and correctly installed. If the issue persists, check the 24 Vac power supply at the thermostat terminals using a multimeter. Ensure the power supply is functioning correctly.
Issue: System doesn’t respond to temperature changes. Solution: Confirm the system mode (Heat, Cool, Off) is set appropriately. Inspect wiring connections for looseness or corrosion, particularly at the thermostat base and the HVAC unit. A faulty wire can interrupt communication.
Issue: Incorrect temperature readings. Solution: Ensure the thermostat isn’t exposed to direct sunlight or drafts, which can affect accuracy. Recalibrate the thermostat if possible, consulting the full manual for specific instructions. If problems continue, professional HVAC assistance may be needed.
Issue: Heat pump not operating correctly. Solution: Verify compatibility – this model supports single-stage heat pumps without auxiliary heat. Check the reversing valve wiring if the system is switching between heating and cooling unexpectedly.
Error Codes and Their Meanings
While the Honeywell TH1110D2009 is a relatively simple thermostat, certain conditions may trigger diagnostic indicators. A flashing display, or specific patterns, can signal underlying issues. Unfortunately, detailed error code documentation for this specific model is limited in publicly available resources.
Generally, a rapidly flashing display often indicates a loss of power or a communication fault with the HVAC system. A slower flash might suggest a sensor error. If an error persists, consult a qualified HVAC technician. The manual itself provides minimal error code details, emphasizing checking power supply and wiring connections first.
Important Note: Due to the thermostat’s non-programmable nature, complex error codes are less common. Troubleshooting primarily involves verifying basic functionality – power, wiring, and system mode selection. For comprehensive diagnostics, professional service is recommended.
Battery Replacement Instructions
The Honeywell TH1110D2009 thermostat requires two AA batteries for operation, even when connected to 24 Vac power. Low battery power will be indicated by a low battery icon on the display. To replace the batteries, locate the battery compartment, typically accessed by removing the thermostat faceplate.
Carefully detach the faceplate from the base. Remove the old batteries and install two new, fresh AA alkaline batteries, ensuring correct polarity (+ and -). Reattach the faceplate securely to the base. The thermostat should now operate normally.
Technical Details
The Honeywell TH1110D2009 operates on 24 Vac and utilizes AA batteries as a power source. It complies with relevant regulations, excluding sales in Colorado after January 1, 2026.
Power Requirements: AA Batteries
The Honeywell TH1110D2009 thermostat is designed to operate using standard AA batteries as its primary power source. While compatible with 24 Vac systems, the batteries ensure continued functionality even during temporary power outages, maintaining your programmed settings and temperature control.
It’s recommended to use high-quality alkaline AA batteries for optimal performance and longevity. The thermostat requires two AA batteries for operation. Battery life will vary depending on usage patterns and environmental factors.
Regularly check the battery level, as indicated on the thermostat display. When the low battery indicator appears, promptly replace both batteries simultaneously with fresh ones to avoid any interruption in heating or cooling. Do not mix old and new batteries.
Voltage Compatibility: 24 Vac
The Honeywell TH1110D2009 thermostat is specifically designed for compatibility with 24 Vac (Volt-Alternating Current) heating and cooling systems. This low-voltage system is standard in most residential and many commercial HVAC setups. It’s crucial to verify your existing system operates on 24 Vac before installation to ensure proper functionality and avoid potential damage.
The thermostat receives its operating power from the 24 Vac transformer within your heating and cooling system. This voltage provides the necessary energy for the thermostat to control the heating and cooling equipment.
Important Note: Do not connect the thermostat to any voltage source other than 24 Vac. Attempting to use a higher voltage could result in severe damage to the thermostat and potentially create a safety hazard.
Regulatory Compliance and Restrictions (Colorado, January 1, 2026)
Please be aware of specific regulatory restrictions concerning the Honeywell TH1110D2009 thermostat. As of January 1, 2026, due to local regulations within the state of Colorado, this product is not permitted for sale or installation.
This restriction applies to all channels, including retail stores and online vendors servicing Colorado addresses. Resideo Technologies, Inc., the manufacturer, adheres to all applicable state and local laws. Customers in Colorado are advised to seek alternative thermostat solutions that comply with current regulations.
This restriction is currently limited to the state of Colorado and does not affect availability in other regions of the United States. We encourage checking local regulations before purchasing or installing any HVAC control device.
Product Information
The Honeywell Home trademark is licensed from Honeywell International, Inc. This thermostat is manufactured by Resideo Technologies, Inc., with readily available datasheets and manuals.
Honeywell Home Trademark Licensing
The prominent Honeywell Home brand, featured on the TH1110D2009 thermostat and within this comprehensive guide, is not directly owned by Resideo Technologies, Inc., the manufacturer of this product. Instead, Resideo operates under a formal licensing agreement with Honeywell International, Inc. This agreement grants Resideo the authorized right to utilize the highly recognized Honeywell Home trademark on its range of smart and connected home comfort solutions.
This licensing arrangement ensures that consumers can confidently associate the quality and reliability historically linked with the Honeywell name with the innovative thermostat products developed and produced by Resideo. It’s a testament to the enduring value of the Honeywell brand and a commitment to maintaining high standards in home comfort technology. Resideo is proud to carry this legacy forward.
Manufacturer: Resideo Technologies, Inc.
Resideo Technologies, Inc. is the dedicated manufacturer responsible for the design, engineering, and production of the Honeywell TH1110D2009/U T1 Pro Series thermostat. While marketed under the esteemed Honeywell Home brand – utilized with permission from Honeywell International, Inc. – Resideo independently oversees all aspects of the product lifecycle, from initial concept to final assembly and quality control.
As a leading global provider of home comfort and security solutions, Resideo is committed to innovation and delivering reliable, user-friendly products. The company, along with its affiliated entities, maintains rigorous manufacturing standards to ensure the TH1110D2009 meets or exceeds industry expectations. Resideo’s dedication extends to providing comprehensive support and documentation, including this detailed manual.
Datasheet and Manual Availability
Comprehensive documentation for the Honeywell TH1110D2009/U T1 Pro thermostat is readily accessible to both professionals and end-users. A detailed datasheet outlining the product’s specifications, features, and compatibility information can be found online through various channels, including the Resideo website and authorized distributor platforms.
The complete installation and operation manual, as referenced throughout this guide, is also widely available. Users can conveniently view it using built-in browser PDF viewers, universal document viewers, or through cloud storage services like Google Docs and Google Drive. Digital copies allow for easy download and offline access. Honeywell Home’s usermanual.wiki provides another valuable resource for accessing this information, ensuring users have the support they need.