Honeywell T4 Programmable Thermostat
Thermostat Interface
Status Icons
Schedule On: Programmed schedule is active.
AUTO 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% (see Changing the Batteries).
Heat Demand: Room temperature is below setpoint – indicating
there is a demand for heating (boiler activity might occur).
Wireless Signal: The thermostat (T4R only) is connected to the Receiver Box.
Menu: Options and settings of your Thermostat:
Heating schedule
Clock
Date
Keypad lock
Optimization
OpenTherm® boiler alerts (T4M only)
Away Mode
Back: Return to the previous screen/menu.
Confirm: Confirm a change or selection.
Timed override: Set a timed duration for the override.
Standby: Turns the heating on or off.
Home: Returns you directly back to the home screen.
- Press
the button to enter the main menu.
- Press
or
buttons to select a menu item – the selected item will flash.
- Press
to confirm the selection.
- Press
or
to adjust a setting and
- press to
save change or advance to the next selection.
- press to
go back to the previous selection.
- press to
save the change and return to the home screen.
Heating schedule
Your Thermostat comes with the following default schedule. Follow the next steps to adjust the heating schedule
Days 1 to 5 (Mon to Fri) | Days 6 & 7 (Sat & Sun) | |||
Period | Time | °C | Time | °C |
P1 | 6:30 – 8:00 | 19 °C | 8:00 – 10:00 | 19 °C |
P2 | 8:00 – 18:00 | 16 °C | 10:00 – 18:00 | 16 °C |
P3 | 18:00 – 22:30 | 21 °C | 18:00 – 23:00 | 21 °C |
P4 | 22:30 – 6:30 | 16 °C | 23:00 – 8:00 | 16 °C |
Days 1 to 5 (Mon to Fri) | Days 6 & 7 (Sat & Sun) | |||
Period | Time | °C | Time | °C |
P1 | 6:30 – 8:00 | 19 °C | 6:30 – 10:00 | 19 °C |
P2 | 8:00 – 12:00 | 16 °C | 10:00 – 12:00 | 16 °C |
P3 | 12:00 – 14:00 | 21 °C | 12:00 – 14:00 | 21 °C |
P4 | 14:00 – 18:00 | 16 °C | 14:00 – 18:00 | 16 °C |
P5 | 18:00 – 22:30 | 21 °C | 18:00 – 23:00 | 21 °C |
P6 | 22:30 – 6:30 | 16 °C | 23:00 – 6:30 | 16 °C |
- Press
to enter the main menu
- Press
or
select the schedule menu
and press
- Press
or
to select the day to be adjusted and press
- Press
or
to select the period to be adjusted and press
- Press
or
to adjust the start time and press
- Press
or
to adjust the end time and press
- Press
or
to adjust the temperature and press
- To copy the schedule you have set, go to the day you want to copy to, press
then select “YES” and press
to confirm
- Repeat these steps to make adjustments to the remaining periods and days – or press
to save changes and return to the home screen
Clock
- To make adjustments to the clock format or time.
- Press
to
enter the main menu.
- Press
or
to select the Clock menu
and press
- Press
or
to change the clock format and press
- Press
or
to adjust the time and press
Date
To make adjustments to the date – Year/Month/Day.
- Press
to enter the main menu.
- Press
or
to select the Date menu
and press
- Press
or
to adjust year (JA) and press
- Press
or
to adjust month (MO) and press
- Press
or
to adjust day (DA) and press
Keypad lock
You can lock the keypad to prevent unnecessary adjustments to the Thermostat.
- Press
to enter the main menu.
- Press
or
to select the Keypad lock
- Press
then select ON to activate it or OFF to cancel it.
- To unlock the Keypad press and hold the Left and Right buttons for 5 sec.
- To lock the Keypad repeat step 2
Optimization
Your Thermostat has optimization functions that aim to save energy while maintaining suitable comfort levels. The Thermostat displays during the optimization period if set. By default optimization is disabled,
see instructions in the installation guide on how to activate it.
- 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 optimization function:
- Press to enter the main menu.
- Press
or
to select the Optimisation menu
and press
- Press
or to
select an option and press
- Press
or
to change the optimization function and press
- Press
to save changes and return to the home screen.
OpenTherm® boiler alerts (T4M only)
If you have T4M Thermostat fitted to an OpenTherm® boiler, you can view alerts received from the boiler about your heating system.
- Press
to enters the main menu.
- Press
or
to select the OpenTherm alerts menu
and press
- Press
or to
cycle through the list of boiler alerts.
- Press
to return to the home screen.
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.
- Press
to enter the main menu.
- Select the Away mode by pressing the icon
from the sub-menu.
- Press
or
to select the number of days you will be away and press
- Press
or
to set the temperature while you are away and press
- Deactivate the Away mode by following the same steps.
Standby mode (with frost protection)
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 of time. If the temperature drops to 5°C the heating will come on to prevent the heating pipes from freezing.
- Press
to switch the heating off – the display will show OFF
- Press
a gain to switch the heating on – the display will show
Schedule Override
During normal use, your Thermostat will follow the programmed schedule – indicated by the AUTO icon in the top right of the display. There are a few ways you can override the schedule to suit your current needs
AUTO Temporary Override
Set until the next programmed setpoint is reached.
- Press or to set the new desired temperature. The programmed schedule will resume at the next programmed setpoint. To cancel press the middle button
23 H Timed Override
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.
- Press or to set the new desired temperature and press
to activate the timer.
- Press or to select 1 or 23 Hours and press
- To cancel the timed override press
again from the home screen.
Turn the Schedule Off (Manual Mode)
Turn the heating schedule off and permanently follow a single (adjustable) temperature – until the schedule is turned on again.
- Press the middle button
- The word MAN will appear on the top right-hand corner.
- To return to the schedule press the middle button again.
- The word AUTO will appear on the top right-hand corner.
Delete period
Turn the heating schedule off and permanently follow a single (adjustable) temperature – until the schedule is turned on again.
- Go to the schedule
- Go to the period you want to delete e.g. P2*.
- Press and hold
the button for 5 seconds.
will appear on the screen.
- You re-activate a deleted period by pressing again the button
for 5 secs.
*The first period can’t be deleted.
Changing the Batteries (T4 & T4R only)
The Thermostat is powered by batteries, although a battery icon is not shown on the display during normal use. The only time you will see the battery icon is when they get low on power.
is displayed when battery power has reached approximately 10% – you should be prepared to change them soon.
-
+
will flash when battery power has become critically low – you should change them immediately to make sure there is no disruption to your heating system
- Replace with 2 new 1.5V LR6 AA Alkaline batteries only – which should last approximately 2 years depending on Thermostat use.
- Pull the Thermostat off the wall bracket or table stand.
- Remove old batteries and insert new ones.
- Clip the Thermostat onto a wall bracket or table stand.
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 the Thermostat loses wireless communication or becomes faulty, the boiler can be switched on or off manually using the button on the Receiver Box.
is displayed on the Thermostat when the wireless signal is
+
will flash on the Thermostat when the wireless signal is lost – The Receiver Box
LED will flash RED.good – The receiver box
LED will be solid GREEN.
- If communication is lost move the Thermostat to another location to try and restore communication.
To manually override the boiler using the Receiver Box:
- Press the button once to switch the boiler ON or OFF. The button LED should be:
- Solid GREEN when the boiler is ON.
- Off when the boiler is OFF.
Troubleshooting
If you have difficulty with your Thermostat, try these suggestions. Most problems can be corrected quickly and easily.
All models | |
Screen is blank![]() |
Replace the batteries (T4 & T4R only).
Check the OpenTherm boiler has power (T4M only). Contact installer. |
Thermostat shows![]() ![]() |
Batteries have less than 10% power and need to be replaced soon. |
Thermostat shows + | Batteries are critically low and need to be replaced immediately – see ‘Changing the Batteries’. |
Thermostat shows but the boiler does not switch on. | The boiler cycles on and off as it controls the temperature, and sometimes the icon will be displayed when the boiler has cycled off.
If the boiler doesn’t switch on after a long period of time contact your installer. |
Heating system does not respond to temperature adjustments. | Make sure the set temperature is higher than the actual room temperature.
Check the heating system is powered on. Check the Receiver Box is powered and the Thermostat has a wireless signal (T4R only). |
Thermostat shows
|
The temperature sensor of your Thermostat is faulty, contact your installer to repair
or replace the Thermostat. |
T4R (Wireless) Thermostat & Receiver Box only | |
Thermostat is flashing ![]() ![]() |
Wireless signal lost – Move the Thermostat to another location to try and restore communication. |
Thermostat is flashing ![]() ![]() |
Check Receiver Box has power by pressing the button to switch boiler on.
If Receiver Box has power then no wireless binding data stored – Follow binding procedure in the installation guide or contact your installer. |
Receiver Box ![]() |
Receiver Box is in binding mode – will time out of this mode after 3 minutes. |
T4M (OpenTherm) Thermostat only | |||
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. | |||
Description | ID | Error code | OT Reading |
Service request | 001 | 01SR | 0 = service not required 1 = service required |
Low water pressure | 002 | 02WP | 0 = no WP fault 1 = WP fault |
Gas/flame fault | 003 | 03GF | 0 = no GF fault 1 = GS fault |
Air pressure fault | 004 | 04AF | 0 = no AP fault 1 = AP fault |
Water Over Temperature | 005 | 05WT | 0 = no OVT fault 1 = OVT fault |
OEM specific | 006 | 06OS | Boiler manufacturer specific code |
2020 Resideo Technologies, Inc. All rights reserved.
The Honeywell Home trademark is used under license from Honeywell International Inc.
This product is manufactured by Resideo Technologies, Inc. and its affiliates.
Pittway 200 Berkshire Place, Wharfedale Road, Winnersh,
Berkshire, RG41 5RD
http://homecomfort.resideo.com/
Tel: 0300 130 1299
32318059-001 D
REFERENCE
Download Manual
Honeywell T4 Programmable Thermostat User
OTHER MANUALS
Honeywell T4 Programmable Thermostat Product SPECIFICATION SHEET
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