Honeywell Home T4, T4R & T4M Thermostat User Guide

Introduction

This document provides a user guide for the Honeywell Home T4, T4R, and T4M thermostats.

The T4 is a programmable thermostat.

The T4M is a programmable modulating thermostat.

The T4R is a wireless programmable thermostat.

Thermostat Interface

The thermostat display and controls are organized as follows:

Key Elements:

• Setpoint periods: Indicates the programmed heating periods.
• Days of week: Shows the current day or selected days (1-7).
• Current time / Timer: Displays the current time or timer setting.
• Menu items: Icons representing available menu options.
• Alert / Fault: Indicates system alerts or faults.
• Room temperature: Displays the current ambient room temperature.
• Setpoint temperature: Shows the target temperature.
• Heat demand: Indicates when the heating system is active.
• Low battery: Appears when the battery power is low.
• Wireless Signal (T4R only): Shows the strength of the wireless connection.
• Schedule status: Indicates if the programmed schedule is active or overridden.
• Temperature adjustment / Menu navigation: Buttons (+) and (-) for adjusting settings and navigating menus.

Navigation Buttons:

• ☰ Menu: Accesses the main menu options.
• ↩️ Back: Returns to the previous screen or menu.
• ✅ Confirm: Confirms a selection or change.
• ❌ Cancel: Rejects a change without saving.
• ⏱️ Timed override: Sets a temporary override for a specific duration.
• ? Standby mode: Turns the heating on or off.
• ✈️ Away mode: Turns heating off for a set period.
• ? Home screen: Returns to the main display.

Status Icons

• ?️ Schedule On: Programmed schedule is active.
• ?️➡️ Schedule Override: Active until the next scheduled period starts or the timed override duration has ended.
• ?️❌ Schedule Off: Programmed schedule is turned off.
• ? Low Battery: Power has reached approximately 10% - flashes when critically low.
• ? Heat Demand: Room temperature is below setpoint, indicating a demand for heating.
• ? Wireless Signal: Thermostat (T4R only) is connected to the Receiver Box.

Menu & Navigation

Menu Options:

• ? Heating schedule: Set and adjust heating times and temperatures.
• ⏰ Clock: Set the clock format and time.
• ? Keypad lock: Lock the keypad to prevent accidental changes.
• ⚙️ Optimisation: Configure energy-saving features like Optimum Start/Stop.
• ⚠️ OpenTherm® boiler alerts (T4M only): View alerts from an OpenTherm® compatible boiler.

Navigating the Menu:

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select a menu item; the selected item will flash.
3. Press the ✅ button to confirm the selection.
4. Press the ◀️ or ▶️ buttons to adjust a setting:
   • Press ✅ to save the change or advance to the next selection.
   • Press ↩️ to go back to the previous selection.
   • Press ? to save changes and return to the home screen.

Heating Schedule

Your Thermostat comes with a default schedule. Follow these steps to adjust it:

Default Schedule:

Adjusting the Schedule:

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select the schedule menu ? and press ✅.
3. Press the ◀️ or ▶️ buttons to select EDIT and press ✅.
4. Press the ◀️ or ▶️ buttons to select the day to be adjusted and press ✅.
5. Press the ◀️ or ▶️ buttons to select the period to be adjusted and press ✅.
6. Press the ◀️ or ▶️ buttons to adjust the start time and press ✅.
7. Press the ◀️ or ▶️ buttons to adjust the end time and press ✅.
8. Press the ◀️ or ▶️ buttons to adjust the temperature and press ✅.
9. Repeat these steps to make adjustments to the remaining periods and days, or press the ? button to save changes and return to the home screen.

Clock Settings

To make adjustments to the clock format or time:

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select the Clock menu ⏰ and press ✅.
3. Press the ◀️ or ▶️ buttons to change the clock format and press ✅.
4. Press the ◀️ or ▶️ buttons to adjust the time and press ✅.

Date Settings

To make adjustments to the date - Year/Month/Day:

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select the Date menu ? and press ✅.
3. Press the ◀️ or ▶️ buttons to adjust the year and press ✅.
4. Press the ◀️ or ▶️ buttons to adjust the month and press ✅.
5. Press the ◀️ or ▶️ buttons to adjust the day and press ✅.

Keypad Lock

You can lock the keypad to prevent unnecessary adjustments to the Thermostat.

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select the Keypad lock ? and press ✅ to activate it.
3. To unlock the Keypad, press and hold the ◀️ and ▶️ buttons simultaneously for 5 seconds.
4. To lock the Keypad, repeat step 2.

Optimisation

Your Thermostat has optimisation functions that aim to save energy while maintaining suitable comfort levels. The Thermostat displays an optimisation icon ⚙️ during the optimisation period if set.

• Optimum Start: Learns how long it takes your home to reach a set temperature and then turns the heating on a bit earlier to achieve that temperature at the programmed time.
• Delayed Start: Saves energy by slightly delaying the start of heating depending on the difference between the set temperature and the room temperature. The closer these temperatures are, the longer it will delay the start.
• Optimum Stop: Saves energy by switching off a little bit earlier than the programmed time. If your home is up to temperature, you will not notice the effect on the temperature, but you should see a difference in your fuel bill.

To enable or disable an optimisation function:

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select the Optimisation menu ⚙️ and press ✅.
3. Press the ◀️ or ▶️ buttons to select an option and press ✅:
   • 0:8P for Optimum Start or Delayed Start
   • 0:9S for Optimum Stop
4. Press the ◀️ or ▶️ buttons to change the optimisation function and press ✅:
   • 0:8P 0 = Optimum Start disabled
   • 0:8P 1 = Optimum Start enabled
   • 0:8P 2 = Delayed Start enabled
   • 0:9S 0 = Optimum Stop disabled
   • 0:9S 1 = Optimum Stop enabled
5. Press the ? button to save changes and return to the home screen.

OpenTherm® Boiler Alerts (T4M only)

If you have a T4M Thermostat fitted to an OpenTherm® boiler, you can view alerts received from the boiler about your heating system. You can view these in the 'OpenTherm® boiler alerts' menu.

1. Press the ☰ button to enter the main menu.
2. Press the ◀️ or ▶️ buttons to select the OpenTherm alerts menu ⚠️ and press ✅.
3. Press the ◀️ or ▶️ buttons to cycle through the list of boiler alerts.
4. Press the ? button to return to the home screen.

Standby and Away Modes

Standby Mode (with frost protect)

Save energy by switching the heating off when not required, e.g., during warmer summer months, or when doors and windows are open for extended periods. If the temperature drops to 5°C, the heating will come on to prevent the heating pipes freezing.

1. Press the ? button to switch the heating off - the display will show "OFF".
2. Press the ? button again to switch the heating on - the display will show the current temperature.

Away Mode

Save energy by switching the heating off for a set period of time while you are away from home, and back on again in time for your return.

1. Press the ✈️ button to enter the away mode menu.
2. Press the ◀️ or ▶️ buttons to select the number of days you will be away and press ✅.
3. Press the ◀️ or ▶️ buttons to set the temperature while you are away and press ✅.
4. To cancel Away mode, press the ✈️ button again from the home screen.

Schedule Override

During normal use, your Thermostat will follow the programmed schedule, indicated by the ?️ icon. There are a few ways you can override the schedule to suit your current needs.

Temporary Override

Set until the next programmed setpoint is reached. The programmed schedule will resume at the next programmed setpoint.

1. Press the ◀️ or ▶️ buttons to set the new desired temperature.

Timed Override (1 or 2 hours)

Can be used to Boost (increase) the heating for a short period or as an Economy (decreased) setting if leaving the house for a short period.

1. Press the ◀️ or ▶️ buttons to set the new desired temperature and press the ⏱️ button to activate the timer.
2. Press the ◀️ or ▶️ buttons to select 1 or 2 Hours and press ✅.
3. To cancel the timed override, press the ⏱️ button again from the home screen.

Turn Schedule Off (Manual Mode)

Turn the heating schedule off and permanently follow a single (adjustable) temperature until the schedule is turned on again.

1. Press the ◀️ or ▶️ buttons to select the schedule menu ? and press ✅.
2. Press the ◀️ or ▶️ buttons to select OFF and press ✅.
3. Press the ◀️ or ▶️ buttons to adjust the permanent temperature.
4. Repeat above steps and choose ON to follow the schedule.

Changing the Batteries (T4 & T4R only)

The Thermostat is powered by batteries. A battery icon ? is displayed when battery power has reached approximately 10%, indicating they should be prepared for replacement soon.

A flashing ? with ➕ will appear when battery power is critically low, requiring immediate replacement to ensure uninterrupted heating system operation.

Replace with 2 new 1.5V LR6 AA Alkaline batteries. These should last approximately 2 years depending on Thermostat use.

Battery Replacement Steps:

1. Pull the Thermostat off the wall bracket or tablestand.
2. Remove old batteries and insert new ones.
3. Clip the Thermostat onto the wall bracket or tablestand.

Please help to protect the environment by recycling old batteries in accordance with local regulations. ♻️

Wireless Receiver Box (T4R only)

The T4R Thermostat communicates wirelessly to the Receiver Box, which is wired to the boiler. If wireless communication is lost or the Thermostat becomes faulty, the boiler can be switched on or off manually using the button on the Receiver Box.

• A ? icon displayed on the Thermostat indicates good wireless signal, and the Receiver Box LED will be solid GREEN.
• A flashing ? with ➕ on the Thermostat indicates the wireless signal is lost, and the Receiver Box LED will flash RED.
• If communication is lost, move the Thermostat to another location to try and restore communication.

Manually Overriding the Boiler:

To manually override the boiler using the Receiver Box:

1. Press the button once to switch the boiler ON or OFF. The button LED should be:
   • Solid YELLOW when the boiler is ON.
   • OFF when the boiler is OFF.

Important: Do not press the small reset 'pinhole' button, as this will clear the receiver box binding data and disrupt the operation of the heating system.

Troubleshooting

If you encounter difficulties with your Thermostat, try these suggestions. Most problems can be corrected quickly and easily.

All Models

T4R (Wireless) Thermostat & Receiver Box Specifics

T4M (OpenTherm) Thermostat Specifics

An OpenTherm boiler can report alerts back to the Thermostat, which can be useful when contacting an installer or maintenance engineer. You can view these in the 'OpenTherm® boiler alerts' menu.