EasyManua.ls Logo

Honeywell T8624D - User Manual

Honeywell T8624D
12 pages
Save Page as PDF
Print Icon
To Next Page IconTo Next Page
To Next Page IconTo Next Page
Loading...
® U.S. Registered Trademark
Copyright © 2002 Honeywell • • All Rights Reserved
INSTALLATION INSTRUCTIONS
69-1412-1
T8624D Chronotherm
®
IV
Deluxe Programmable
Multistage Thermostats
APPLICATION
The T8624D Chronotherm® IV Deluxe Programmable
Multistage Thermostats provides electronic control of 24
Vac single-zone multistage systems.
Refer to Table 1 for a general description of the
thermostats. All T8624 thermostats require a common
wire to supply power.
Table 1. Description of T8624 Thermostats.
MERCURY NOTICE
If this control is replacing a control that contains
mercury in a sealed tube, do not place your old
control in the trash. Dispose of properly.
Contact your local waste management authority
for instructions regarding recycling and the
proper disposal of the old control.
INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow
the instructions can damage the product or cause
a hazardous condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for
your application.
3. Installer must be a trained, experienced service
technician.
4. After completing installation, use these instructions
to check out the product operation.
Location
Install the thermostat about 1.5m (5 ft) above the floor in
an area with good air circulation at average temperature.
See Fig. 1.
Do not install the thermostat where it can be affected by:
— drafts, or dead spots behind doors and in corners.
— hot or cold air from ducts.
— radiant heat from sun or appliances.
— concealed pipes and chimneys.
— unheated (uncooled) areas such as an outside wall
behind the thermostat.
T8624 Changeover System Selection
Fan
Selection Comments
D Automatic Heat-Off-Cool-Auto On-Auto System and fan selections are done by keyboard.

Table of Contents

Questions and Answers

  • S
    Stephanie MoralesAug 12, 2025
    Why is my Honeywell T8624D heating not working?
    • S
      shannon56Aug 12, 2025
      Your Honeywell Thermostat might not be heating because of several reasons: * There may be no power to the thermostat. Check for 24 Vac between R and W terminals. If there's no 24 Vac, check the circuit breaker (reset if tripped), the system fuse (replace if blown), the HVAC equipment power switch (set to On), and the wiring between the thermostat and HVAC equipment (replace broken wires and tighten loose connections). If 24 Vac is present, continue troubleshooting. * The thermostat's minimum off time might be activated. Wait up to five minutes for the system to respond. * The system selection might not be set to Heat. Ensure the system selection is set to Heat. * The heating setpoint might be below room temperature. Check the heating setpoint and set it to the desired temperature.
  • B
    barbaracolonAug 19, 2025
    What to do if temperature settings will not change on Honeywell T8624D Thermostat?
    • J
      Joshua RobertsAug 19, 2025
      If you cannot adjust the temperature settings on your Honeywell Thermostat, it could be due to the following: * You might have reached the upper or lower temperature limits. Check the temperature setpoints. Heating limits are 40 to 90°F (7 to 31°C), and cooling limits are 48 to 99°F (9 to 37°C). * Setpoint temperature range stops may have been configured. Check Installer Setup numbers 34 and 35 and reconfigure the setpoint stops.
  • J
    john25Aug 23, 2025
    How to fix Honeywell T8624D Thermostat when display will not come on?
    • L
      Lawrence StokesAug 23, 2025
      If the display on your Honeywell Thermostat won't turn on, it might not be getting power. Check for 24 Vac between the R and C terminals. If there is no 24 Vac: * Check if the circuit breaker is tripped—reset the circuit breaker. * Check if the system fuse is blown—replace the fuse. * Check if the power switch on the HVAC equipment is in the Off position—set to the On position. * Check wiring between thermostat and HVAC equipment—replace any broken wires and tighten any loose connections. If 24 Vac is present, proceed with troubleshooting.
  • A
    Alicia LamAug 27, 2025
    Why is my Honeywell T8624D Thermostat temperature display incorrect?
    • D
      Danny WilsonAug 27, 2025
      If the temperature display on your Honeywell Thermostat is incorrect, it could be due to a few reasons: * The room temperature display may have been reconfigured. Enter Installer Setup number 37 and reconfigure the display. * The thermostat might be configured for °F or °C display. Enter Installer Setup number 14 and reconfigure the display. * The thermostat's location might be causing inaccurate readings. Relocate the thermostat.
  • J
    James MartinAug 31, 2025
    Honeywell T8624D Thermostat shows heat/cool but no air is coming out. What should I do?
    • A
      Austin StewartAug 31, 2025
      If your Honeywell Thermostat displays the system on indicator (flame for heat, snowflake for cool) but no warm or cool air is coming from the registers, the heating or cooling equipment might not be operating. Verify the operation of the heating or cooling equipment in self-test.
  • J
    James WestSep 3, 2025
    Why is the outdoor temperature display incorrect on my Honeywell T8624D Thermostat?
    • A
      andreasnyderSep 3, 2025
      If the outdoor temperature display is incorrect on your Honeywell Thermostat, it could be due to: * The outdoor sensor being connected incorrectly. Refer to the C7089B1000 Installation Instructions and check the wiring between the thermostat and the sensor. * Using the wrong sensor. Replace the sensor with a C7089B1000 Sensor.
  • A
    Anthony GarciaSep 7, 2025
    How do I display the outdoor temperature on my Honeywell T8624D Thermostat?
    • K
      Kelly WilliamsSep 8, 2025
      To display the outdoor temperature on your Honeywell Thermostat, enter Installer Setup number 24 and set it to 1. Note that the thermostat must have OT terminals and a C7089B1000 installed.
  • S
    Sandra PrattNov 15, 2025
    Why is my Honeywell Thermostat cooling not working?
    • E
      Edwin AlvaradoNov 15, 2025
      Your Honeywell Thermostat might not be cooling due to several reasons: * There may be no power to the thermostat. Check for 24 Vac between R or RC. If there's no 24 Vac, check the circuit breaker (reset if tripped), the system fuse (replace if blown), the HVAC equipment power switch (set to On), and the wiring between the thermostat and HVAC equipment (replace broken wires and tighten loose connections). If 24 Vac is present, continue troubleshooting. * The thermostat's minimum off time might be activated. Wait up to five minutes for the system to respond. You can also enter Installer Setup number 33 to reconfigure the minimum off time if needed. * The system selection might not be set to Cool. Ensure the system selection is set to Cool. * The cooling setpoint might be above room ...

Summary

Application Overview

Mercury Disposal Notice

Installation Guidelines

Location Requirements

Install the thermostat at 1.5m (5 ft) above the floor in an area with good air circulation.

Wallplate and Wiring Installation

Wallplate Mounting Procedure

Position, level, mark, drill, and secure the wallplate, pulling wires through.

Wiring Safety Precautions

Disconnect power before wiring to avoid shock or equipment damage.

Thermostat Mounting and Wiring Details

Mounting Thermostat Unit

Engage top tabs and press lower edge to latch; procedure for removal is also noted.

Correct Wiring Technique

Ensure proper wire connection and insulation for thermostat wiring.

Thermostat Operation and Settings

Keypad Functions Overview

Overview of keys used for time, programs, overrides, and system configuration.

System and Fan Settings

Configure system operation (Heat, Cool, Auto) and fan operation (On, Auto).

Installer Setup Procedures

Entering and Navigating Installer Setup

Press 'i' with ▲/▼ to enter; use Time ▲ to advance, ▲/▼ to change, Time ▼ to go back.

Installer Setup Options

Table 3 details configuration options and factory settings for system customization.

Advanced Setup Options

Temperature Display and Timer Settings

Adjust temperature display and configure furnace filter/monitor timers.

Setting Current Day and Time

Setting Time and Day

Press Set Current Day/Time, select day, then adjust time using Time ▲ or Time ▼ keys.

Timer Settings Management

Resetting Expired Timers

Press 'i' to display timer, then Time ▼ to reset.

Installer System Test

Initiating and Cautions

Press ▲/▼ to initiate test; be aware of bypassed compressor off-time.

System Test Execution

Heating, Cooling, and Fan Tests

Execute tests for heating, cooling stages, and fan operation.

Key Operation Test

Verify the functionality of all thermostat keys during the test.

Thermostat Information and Checkout

Displaying Information Codes

View production date, software ID, revision, and EEPROM identification codes.

Checkout Procedures

Perform checkout for outdoor temperature sensor (select models).

Troubleshooting Guide

Display and Setpoint Troubleshooting

Diagnose issues with display, temperature readings, and setpoint limits.

Heating;Cooling Operation Troubleshooting

Address problems with heating/cooling not working or minimum off-time.

Additional Troubleshooting

Airflow and Indicator Issues

Troubleshoot system indicator status versus actual airflow and register output.

Outdoor Sensor Issues

Resolve problems with outdoor temperature sensor display or accuracy.

Honeywell T8624D Specifications

General IconGeneral
BrandHoneywell
ModelT8624D
CategoryThermostat
LanguageEnglish

Related product manuals