Honeywell Home T6861H2WG Fancoil On/Off Thermostat

T6861 Series Large LCD Digital Thermostat Overview

Features:

• Modern design for office, hotel, and residential buildings.
• Horizontal and vertical models.
• Slim design for direct installation on 86-size boxes.
• Blue/green backlight with a color ring.
• Integrated 2-pipe/4-pipe configuration.
• Large LCD display with English and icons.
• Easy installation and setup.
• Time on/off function.
• Selectable room temperature or setpoint display.
• Manual or automatic fan speed selection.
• Remote temperature sensor.
• Energy-saving mode activation.
• Cycle per Hour (CPH) function.
• Adjustable display room temperature.
• Temperature unit selectable (°C or °F).
• User settings retention during power off.
• Freezing protection function.
• Lock/unlock keys or part of keys in Installer Setup.
• Heat and cool setpoint limitations for energy saving.

Application: Designed for 3-speed fan and valve control in fan coil systems. It supports:

• 2-pipe cool only/heat only/manual changeover.
• 4-pipe manual or automatic changeover.
• Ventilation mode.
• Manual or automatic 3-speed fan control.
• Water valve control.

Models:

• Horizontal and vertical models with blue or green backlight and color ring.
• Power supply options: 110V or 220V.

Mechanical Design:

• Thermostat appearance includes a large LCD display and various buttons (power, mode, fan, up, down).
• Indicates room temperature, current fan setting, mode setting, time on/off, keypad lock status, freezing protection, and thermostat activity.

Functions:

• Valve Control: Maintains setpoint by delivering on/off valve control commands.
• Fan Operation: Manual or automatic 3-speed operation based on room temperature.
• Four-Pipe Application: Manages heating and cooling setpoints with a fixed deadband for Automatic Change Over (ACO).
• Cycle per Hour (CPH): Ensures accurate temperature control by opening the valve several times per hour.
• Time On/Off: Allows setting a time range from 0 to 12 hours for automatic on/off functionality.
• Backlight: Activates with any key press and has a timeout of 8 or 60 seconds.
• Remote Temperature Sensor: Supports control based on room or return air temperature.
• Keypad Lock: Allows locking of all or part of the keys.
• Ventilation Mode: No valve output; fan operates based on selected speed.
• Energy Saving Mode: Activatable by dry contact or button press, adjusts setpoints for energy efficiency.
• Operating Modes: Includes comfort mode, cool only, heat only, and manual heat/cool changeover.
• Temperature Display: Can show room temperature or setpoint.

Technical Specifications:

• Power Supply: 110V (+/-10%) or 220V (+10%, -15%) VAC.
• Frequency: 50/60Hz.
• Control Algorithm: PI, On/off output.
• Accuracy: +/-1°C at 21°C.
• Rating Capacity: 4(2)A for fan load, 2(1)A for zone valve.
• Cycle Times: 100,000.
• Setpoint Range: 10~32°C.
• Display Range: 0~37°C.
• Installation: 86×86mm junction box or US2×4 inch.
• Protection Class: IP20.
• Environmental Conditions: Operation temperature -1849°C, shipping temperature -3565°C, relative humidity 5~90%.

Wiring Diagrams:

• Provided for various configurations including 2 pipes heat only, cool only, 1H1C, and 4 pipes with manual/auto changeover.

Installation & Commissioning:

• Step-by-step instructions for pulling wires, loosening screw terminals, inserting wires, and securing the power box.

Installer Set-Up (ISU):

• Access ISU by pressing specific buttons simultaneously.
• Various settings and options can be configured, including system type, remote sensor, temperature scale, fan control type, sequence deadband, CPH values, display temperature adjustment, temperature display mode, heating and cooling range stops, keypad lockout, remote setback enable method, and freeze protection.

Troubleshooting Tips:

• Solutions for issues like heating or cooling system not turning on, fan not working, mode button not working, and other button functionality problems.

Diagram and Dimension Notes:

• Horizontal and vertical model dimensions provided.
• Detailed diagrams for wiring and installation steps.

Troubleshooting Tips:

• Heating system does not turn on:
  • Set the mode to Heat by pressing the Mode button.
  • Ensure the heat temperature setting is above the room temperature and “Heat On” is displayed solidly.
  • Wait five minutes for the heating system to respond.
• Cooling system does not turn on:
  • Set the mode to Cool by pressing the Mode button.
  • Ensure the cool temperature setting is below the room temperature and “Cool On” is displayed solidly.
  • Wait five minutes for the cooling system to respond.
• The fan doesn’t work:
  • Check whether the Fan mode is set to Auto.
  • Ensure the heating or cooling system works.
• The Mode button doesn’t work:
  • Check whether the keypad is locked.
  • Verify if the system is in Energy saving mode.
  • Ensure the thermostat is not off.
• The Fan button doesn’t work:
  • Check whether the keypad is locked.
  • Verify if the system is in Energy saving mode.
  • Ensure the thermostat is not off.
• The Up or Down button doesn’t work:
  • Check whether the keypad is locked.
  • Verify if the system is in Energy saving mode.
  • Ensure the thermostat is not off.

Setup Function Settings & Options:

• System type:
  • 0: Heat only
  • 1: Cool only
  • 2: Two pipes 1H1C manual (Default)
  • 4: Four pipes manual
  • 5: Four pipes auto
• Remote sensor:
  • 0: Onboard Sensor (Default)
  • 1: Remote (NTC20K)
• Temperature scale:
  • 0: °F
  • 1: °C (Default)
• Fan control type:
  • 0: Cycle only
  • 1: Constant only (3 speed: Low->Med->High->Low)
  • 2: User can choose Cycle or Constant (3 speed: Low->Med->High->Auto->Low) (Default)
• Sequence Dead band for four pipes:
  • 1°C (2°F)
  • 1.5°C (3°F) (Default)
  • 2°C (4°F)
  • 3°C (5°F)
  • 3.5°C (6°F)
  • 4°C (7°F)
  • 4.5°C (8°F)
  • 5°C (9°F)
• CPH value for Heat:
  • Range from 1 to 12, default is 4
• CPH value for Cool:
  • Range from 1 to 6, default is 3
• Display Temperature adjustment:
  • Range from -2°C (-4°F) to 2°C (4°F), default is 0°C (0°F)
• Temperature Display mode:
  • 0: Display Room Temperature
  • 1: Display Setpoint
  • 2: Display both (Default)
• Heating Range Stops:
  • 10-32°C default 32°C (50-90°F default 90°F)
• Cooling Range Stops:
  • 10-32°C default 10°C (50-90°F default 50°F)
• Keypad Lockout:
  • 0: All keys available (Default)
  • 1: System button Locked out
  • 2: Fan and System button Locked out
  • 3: All buttons locked out
• Remote setback enable method:
  • 0: Hotel card NO
  • 1: Hotel Card NC
  • 2: Button (Default)
• Remote setback heating setpoint:
  • Range 10-21°C Default: 18°C (Range 50-70°F Default: 64°F)
• Remote setback cooling setpoint:
  • Range 22-32°C Default: 26°C (Range 72-90°F Default: 79°F)
• Freeze Protection:
  • 0: Disabled (Default)
  • 1: Enabled

Installer Set-Up (ISU) Settings:

• Number: Describes the setting.
• Setting: Possible options and default values.
• Operation: Change settings with buttons, advance functions, and save by holding buttons for 3 seconds.

Installer System Test:

• Heat:
  • 0: Heat turn off.
  • 1: Heat turns on.
• Cool:
  • 0: Cool off.
  • 1: Cool on.
• Fan:
  • 0: Fan off
  • 1: Low speed Fan on
  • 2: Medium speed Fan on
  • 3: High speed Fan on
• Thermostat information:
  • Includes software revision numbers, configuration identification codes, and production dates.

Dimensions:

• Horizontal Model
• Vertical Model

Summary:

This document provides comprehensive details about the T6861 Series Large LCD Digital Thermostat, including its features, applications, mechanical design, functions, technical specifications, wiring diagrams, installation instructions, troubleshooting tips, and detailed setup options for both the thermostat and the system.