T855iSH Manual: A Comprehensive Guide
This comprehensive guide details the T855iSH thermostat, covering installation, operation, programming, and advanced features. It includes manuals for installation and operation, alongside submittal and spec sheets.
Access the Technician Setup Menu by holding the TECH SET button for three seconds. Pro1 Technologies provides extensive documentation, with copyright 2020, and supports various configurations like heat pump setups.
Find English and French manuals, alongside 800 other manuals from PRO1. Optimize comfort and energy efficiency through custom schedules and understand system operation indicators and delays.
The T855iSH thermostat represents a significant advancement in home climate control, offering a versatile and user-friendly experience. This thermostat is designed for both professional installers and homeowners seeking enhanced comfort and energy savings. It’s a 24V powered device, compatible with universal sub-bases for flexible mounting options – directly on a wall or within a standard junction box.
This manual serves as a complete resource, guiding users through every aspect of the T855iSH, from initial installation to advanced programming and troubleshooting. Pro1 Technologies, the manufacturer, provides comprehensive documentation, including submittal and spec sheets, ensuring a smooth and informed experience. The thermostat boasts a clear display and intuitive menu navigation, making adjustments straightforward.
Whether you’re configuring a standard heating and cooling system or a more complex heat pump application, the T855iSH offers the flexibility and control you need. This guide will unlock the full potential of your new thermostat, maximizing efficiency and comfort within your home environment.
Key Features and Specifications
The T855iSH thermostat boasts several key features designed for optimal performance and user convenience. It supports custom heating and cooling schedules, allowing for personalized comfort and energy efficiency. A prominent feature is its compatibility with a remote sensor, enabling temperature monitoring in various locations within a home.

This thermostat operates on 24V power and offers a clear display for easy readability. The T855iSH includes system operation indicators and delays, providing insights into system status and preventing short-cycling. Installation is simplified with a universal sub-base, accommodating both wall and junction box mounting.
Pro1 Technologies ensures quality with a U.S. Registered Trademark and pending patents. Detailed spec sheets and submittal sheets are available for comprehensive technical information. The manual provides access to a Technician Setup Menu, accessed by holding the TECH SET button for three seconds.
Package Contents
Upon opening the T855iSH package, users will find a comprehensive set of components for a successful installation and operation. The core component, the T855iSH thermostat itself, is included, alongside a universal sub-base designed for versatile mounting options – whether on a wall or directly onto a junction box.
Essential documentation is provided, encompassing both the Installation/Operation Manual and access to detailed submittal and spec sheets. These resources guide users through setup, programming, and troubleshooting. Pro1 Technologies ensures clarity with readily available manuals in both English and French.
While specific hardware like mounting screws may be included, it’s advisable to verify compatibility with your existing setup. The package facilitates a streamlined experience, backed by Pro1 Technologies’ commitment to quality and comprehensive support, with copyright 2020.

Installation Guide
Installation involves utilizing the universal sub-base for wall or junction box mounting, ensuring proper 24V power wiring, and configuring for heat pump applications as needed.
Universal Sub-Base Mounting
The T855iSH thermostat utilizes a versatile universal sub-base designed for broad compatibility. This sub-base facilitates straightforward installation onto either a standard wall surface or directly onto an existing electrical junction box.
Prior to mounting, ensure the chosen location meets all safety regulations and provides convenient access for future maintenance. The sub-base securely anchors to the wall using appropriate screws (not always included, check package contents), or it can be directly affixed to a junction box using the provided mounting points.
Proper alignment is crucial for a clean and professional installation. Once the sub-base is firmly in place, the T855iSH thermostat unit easily snaps onto the sub-base, establishing a secure electrical and mechanical connection. This modular design simplifies both initial setup and any subsequent servicing or replacement.
Wall Mounting Instructions
For direct wall mounting of the T855iSH thermostat, begin by selecting a suitable location, ensuring it’s away from direct sunlight, drafts, and heat-generating appliances. Use the universal sub-base as a template to mark the screw hole positions on the wall.
Drill pilot holes at the marked locations, appropriate for the wall material. Secure the sub-base to the wall using suitable screws (typically not included), ensuring it is level and firmly attached. Avoid over-tightening, which could damage the sub-base or wall surface.
Once the sub-base is securely mounted, carefully align the T855iSH thermostat with the sub-base and gently snap it into place. Verify a secure connection before proceeding with wiring. A properly mounted thermostat ensures accurate temperature sensing and reliable operation.
Junction Box Mounting Instructions
The T855iSH thermostat is designed for convenient mounting onto a standard junction box, utilizing its universal sub-base. Begin by removing the existing cover plate from the junction box, ensuring power is disconnected at the breaker for safety.

Align the universal sub-base with the screw holes on the junction box. Secure the sub-base using the screws provided with the junction box, ensuring a flush and stable fit. Do not overtighten the screws, as this could damage the sub-base or the junction box itself.
Once the sub-base is firmly attached, carefully align the T855iSH thermostat with the sub-base and gently snap it into place. Verify a secure connection. This mounting method provides a clean and professional installation.
Wiring Diagram – 24V Power
The T855iSH thermostat operates on 24V power, requiring careful wiring for proper functionality. Connect the Rh (Red) wire to the R terminal and the C (Common) wire to the C terminal; These are essential for consistent power supply.
For heating, connect the W (White) wire to the W terminal. For cooling, connect the Y (Yellow) wire to the Y terminal. The G (Green) wire controls the fan and connects to the G terminal. Ensure all wire connections are secure and properly inserted into their respective terminals.
Double-check all wiring against the diagram before restoring power. Incorrect wiring can damage the thermostat or the HVAC system. Refer to a qualified technician if you are unsure about any aspect of the wiring process.
Heat Pump Configuration
Configuring the T855iSH thermostat for heat pump applications requires specific settings within the Technician Setup Menu. Access this menu by pressing the MENU button, then holding the TECH SET button for three seconds – a deliberate delay to prevent accidental access.
Within the setup, you’ll need to define the system type as a heat pump. This involves specifying whether it’s a standard heat pump or a dual-fuel system. Correctly identifying the system ensures proper operation of both heating and cooling modes.
Refer to page 16 of this manual for detailed, step-by-step instructions on heat pump configuration. Incorrect settings can lead to inefficient operation or system malfunction. Always verify the configuration after completion.

Operation and User Interface
The T855iSH boasts an intuitive interface. Understanding the display and navigating the menu system are key to optimal use. Access the Technician Setup Menu easily.
Understanding the Display
The T855iSH thermostat features a clear and informative display designed for easy readability. The primary area showcases the current room temperature, prominently displayed for quick reference. Adjacent to this, you’ll find the setpoint temperature, indicating your desired heating or cooling level.
Various icons illuminate to communicate the system’s status. A flame icon signifies active heating, while a snowflake indicates cooling is in progress. A fan icon displays the fan’s operational mode – auto or on. Flashing indicators signal system delays, such as compressor or cooling delays, providing valuable insight into system operation.
The display also incorporates indicators for remote sensor status, if applicable, and system mode (heat, cool, auto, off). Understanding these visual cues allows for effortless monitoring of your home’s climate control system and quick identification of any operational states.
Navigating the Menu System
The T855iSH thermostat’s menu system is accessed by pressing the “MENU” button on the front panel. This initiates a series of options, allowing for customization of settings and review of system information. Use the up and down arrow buttons to scroll through the available menu items, such as schedule programming, temperature settings, and system configuration.
Selecting a menu item is confirmed by pressing the “SELECT” or “ENTER” button. To return to the previous menu or exit entirely, utilize the “BACK” or “CANCEL” button. The menu structure is logically organized, facilitating intuitive navigation for users of all technical levels.
For advanced settings, including Technician Setup, a prolonged press (3 seconds) of the “TECH SET” button is required, preventing accidental alterations. This ensures that critical system parameters remain secure and are only adjusted by authorized personnel.
Technician Setup Menu Access
Accessing the Technician Setup Menu on the T855iSH thermostat requires a deliberate action to prevent unintended changes to critical system parameters. To enter this mode, press and hold the “TECH SET” button for a full three seconds. This intentional delay is a built-in safety feature, safeguarding against accidental adjustments by standard users.
Upon successful entry, the display will shift to a specialized interface offering advanced configuration options. These options include detailed settings for heat pump operation, sensor calibration, and system diagnostics. Technicians can fine-tune the thermostat’s performance to optimize efficiency and address specific installation requirements.
Remember to exit the Technician Setup Menu after completing adjustments to restore normal user operation. Improper settings can affect system functionality, so careful consideration is crucial.

Programming and Settings
Customize your comfort with custom heating and cooling schedules. Easily set the date and time, and perform temperature calibration for optimal accuracy.
Maximize energy efficiency!
Custom Heating and Cooling Schedules
The T855iSH thermostat empowers users to create personalized heating and cooling schedules, optimizing both comfort and energy savings. This feature allows for precise control over indoor temperatures throughout the day, adapting to individual lifestyles and preferences.
Programming these schedules is straightforward, enabling users to define different temperature setpoints for various time periods. For example, you can schedule lower temperatures during sleep or when the home is unoccupied, and higher temperatures for when the family is awake and active. This granular control minimizes energy waste and reduces utility bills.
The thermostat supports multiple schedule programs, allowing for distinct settings for weekdays and weekends, or even for individual days of the week. This flexibility ensures that the T855iSH seamlessly integrates into any routine, providing consistent comfort and efficient operation. Detailed instructions for setting up these schedules are available within the operation manual.
Setting Date and Time
Accurate date and time settings are crucial for the proper functioning of the T855iSH thermostat, particularly when utilizing its scheduling features. The thermostat relies on the correct time to execute programmed temperature changes at the designated hours.
The process of setting the date and time is typically accessed through the thermostat’s menu system. Users navigate to the settings menu and then select the date and time options. The interface allows for individual adjustment of the month, day, year, hour, and minute.
Ensuring the correct date and time is especially important after a power outage or initial installation. Refer to the operation manual for detailed, step-by-step instructions specific to the T855iSH model. Maintaining accurate timekeeping guarantees the reliability of programmed schedules and optimal energy management.
Temperature Calibration
Temperature calibration allows for fine-tuning the T855iSH thermostat’s temperature readings to match a trusted external thermometer. While the thermostat is manufactured to high precision, slight discrepancies can occur due to environmental factors or installation location.
Accessing the calibration feature is generally found within the Technician Setup Menu. This menu, secured by a hold-down procedure (holding TECH SET for 3 seconds), prevents accidental adjustments. Calibration is expressed in degrees Fahrenheit or Celsius, allowing for incremental adjustments.
Carefully compare the thermostat’s displayed temperature with a calibrated reference thermometer. Adjust the calibration setting until the readings align. Accurate calibration ensures optimal comfort and efficient heating/cooling. Consult the operation manual for specific calibration procedures and recommended tolerances for the T855iSH.

Advanced Features
The T855iSH boasts remote sensor operation, system operation indicators with delays, and comprehensive troubleshooting for common issues, enhancing user control and diagnostics.
Remote Sensor Operation
The T855iSH thermostat supports a remote sensor for measuring temperature in a specific location, offering enhanced comfort and zoning capabilities. This feature allows users to average temperatures between the thermostat and the remote sensor, creating a more consistent and comfortable environment throughout the space.
To utilize the remote sensor, ensure it is properly connected and configured within the Technician Setup Menu. The thermostat can be set to prioritize either the thermostat’s internal sensor, the remote sensor, or an average of both. This flexibility allows for customization based on individual preferences and room characteristics.
Proper placement of the remote sensor is crucial for accurate readings. Avoid direct sunlight, drafts, and proximity to heat-generating appliances. Refer to the complete T855iSH manual for detailed instructions on sensor installation and configuration options, maximizing the benefits of this advanced feature.
System Operation Indicators & Delays
The T855iSH thermostat utilizes indicator lights to communicate the status of your heating and cooling system. A flashing Heat or Cool indicator signifies a system delay, such as compressor delay or cooling delay, preventing short-cycling and protecting equipment. Similarly, a flashing Fan indicator denotes a fan delay.
Understanding these indicators is crucial for troubleshooting. These delays are normal operational functions designed to optimize system performance and longevity. The T855iSH manual provides detailed explanations of each indicator and the corresponding delay mechanisms.
These system operation indicators offer valuable insight into the thermostat’s activity. Refer to the comprehensive manual for a complete understanding of all indicators and their meanings, ensuring proper system operation and efficient energy usage. Ignoring these signals could lead to misdiagnosis.
Troubleshooting Common Issues
The T855iSH manual offers solutions to frequently encountered problems. If the thermostat doesn’t respond, verify 24V power is connected correctly. A blank display often indicates a power issue; check wiring and the power source. For inaccurate temperature readings, utilize the temperature calibration feature detailed in the programming section.
If the system isn’t heating or cooling, confirm the correct mode is selected and that the setpoint is appropriately adjusted. Flashing indicators suggest system delays – consult the ‘System Operation Indicators & Delays’ section.
For more complex issues, accessing the Technician Setup Menu might be necessary. Always refer to the complete manual for detailed troubleshooting steps and contact Pro1 Technologies for further assistance if problems persist.

Technical Documentation
This section provides essential T855iSH resources, including the Submittal Sheet, Spec Sheet, and Pro1 Technologies contact details. Copyright 2020 applies to all documentation.
T855iSH Submittal Sheet
The T855iSH Submittal Sheet serves as a crucial document for contractors and installers, detailing the thermostat’s specifications for project planning and approval processes. It outlines key features like universal sub-base compatibility, enabling mounting on standard walls or directly onto existing junction boxes, simplifying installation procedures.
This sheet comprehensively lists the thermostat’s power requirements – specifically, 24V operation – and confirms its adherence to relevant industry standards. It also highlights the availability of both Installation and Operation Manuals, ensuring users have access to complete guidance. Furthermore, the T855iSH is a U.S. Registered Trademark with patents pending, reflecting Pro1 Technologies’ commitment to innovation.
The submittal sheet provides a concise overview of the thermostat’s capabilities, aiding in informed decision-making during the selection phase. It’s a vital component for ensuring a smooth and compliant installation process, backed by Pro1 Technologies’ support and quality assurance.
T855iSH Spec Sheet
The T855iSH Spec Sheet delivers a detailed technical breakdown of the thermostat, essential for engineers, architects, and technical personnel. It meticulously outlines the device’s dimensions, wiring terminal designations (including 2 Heat and 2 Cool), and operational parameters, ensuring compatibility within diverse HVAC systems.
This document confirms the thermostat’s 24V power requirement and details its compatibility with heat pump configurations, referencing specific instructions found on page 16 of the Installation Manual. It also clarifies the function of system operation indicators, explaining flashing lights signify system delays – compressor or cooling related.
The spec sheet emphasizes the thermostat’s adherence to Pro1 Technologies’ quality standards, noting its U.S; Registered Trademark status and pending patents. It’s a critical resource for verifying performance characteristics and facilitating seamless integration into building automation systems, backed by comprehensive documentation.
Pro1 Technologies Contact Information
For comprehensive support regarding the T855iSH thermostat and related products, Pro1 Technologies offers multiple avenues for assistance. Access to a vast library of 800 manuals, including dedicated Installation and Operation Manuals for the T855iSH, is readily available online.
While specific contact details like phone numbers or email addresses aren’t explicitly provided in the available information, Pro1 Technologies’ commitment to customer satisfaction is evident through their extensive documentation. This includes detailed submittal and spec sheets, alongside troubleshooting guides addressing common issues.
Further inquiries can be directed through their official website, where you can find resources and potentially submit support requests. Pro1 Technologies, located at P.O. Box [address omitted for privacy], remains dedicated to providing quality HVAC control solutions, protected by copyright 2020 and pending patents.
Copyright and Patent Information (Copyright 2020)
Pro1 Technologies asserts full ownership of the intellectual property rights associated with the T855iSH thermostat, including its design, functionality, and accompanying documentation. This encompasses all manuals – Installation, Operation, and technical specifications – as well as the submittal and spec sheets.
The entirety of this work is protected under copyright 2020, granting Pro1 Technologies exclusive rights to reproduce, distribute, and adapt the material. Furthermore, Pro1 Technologies has multiple patents pending related to the innovative technologies incorporated within the T855iSH and its broader product line.
Unauthorized reproduction or distribution of any portion of this documentation, or reverse engineering of the T855iSH thermostat, is strictly prohibited and may be subject to legal action. This protection ensures continued innovation and quality in HVAC control solutions.
