T4M Thermostat
Programmable Modulating Thermostat
OpenTherm Boiler
EN
Quick Start Installation Guide
Compatible with OpenTherm appliances only.
Not compatible with 230V boilers, zone valve
applications or 230V electric heating.
Installation in 3 steps...
Wire the
1
Thermostat
T
T
T
T
S
S
Must be installed by a competent person.
To ensure your safety make sure the mains power
is switched OFF before accessing wiring.
Power Up
2
and Test
Configure
3
the System
OpenTherm
Communication
32318058001 B
Thermostat
A
B
C
T
T
S
S
Polarity free
OT OT
OpenTherm
Boiler
To prevent a short circuit from a loose wire -
• When using multi-core cables: Only remove enough outer
insulation to allow secure fixing of the cores into the terminal block.
• When using single core cables: Secure them together with
a cable tie as close as possible to the terminal block.
1
Wire the Thermostat
Find a suitable wall location away from draughts,
direct sunlight or other heat sources, and where cables
can be run from the boiler to the thermostat.
A) Separate the wallplate from
the thermostat, and using a
screwdriver open the wallplate
terminal cover to connect wires.
max 6mm
1.2-1.5m
B) Connect wires according
to wiring diagrams and
clip the cover closed.
A
B
C
T
T
T
T
S
S
2
Power Up and Test
Power Up the Heating System and do a quick functional test
on the thermostat to check that it switches the boiler.
Press the button to increase
the temperature to maximum and
check the boiler switches on
– The heat demand icon on the
thermostat should be on.
Now press the button to decrease
the temperature to minimum and
check the boiler switches off
– The heat demand icon on the
thermostat should also go off.
min 0.25mm²
max 1.5mm²
3
Configure the System
Specific settings for the thermostat
and heating system can be
configured in the advanced menu.
Press and hold
and then
buttons together until the display
changes (approx. 3 seconds).
A) Press
and buttons to navigate
through the parameter list
C) Press
button to save the change
(or press to cancel the change)
B) Press
and buttons to
change a parameter
D) Press
button to exit advanced
menu and save any changes
Parameter
Number
Parameter
Setting
Parameters
o
N
10:BL
12:DS
13:TO
15:SD
16:FS
Description Settings (default in bold)
Language 1 = EN, 2 = NL, 3 = DE, 4 = FR, 5 = ES
1:LA
Lower Temperature Limit 5 - 21 (°C)
4:LL
Upper Temperature Limit 21 - 35 (°C)
5:UL
Schedule options 1 = 7 day (different schedule each day of the week)
6:SO
Number of periods per day 4 or 6
7:NP
Wired Remote Sensor 0 = No Remote Sensor, 1 = Wired Remote Sensor
8:SS
Fail Safe mode 0 = Boiler off, 1 = Boiler 20% on / 80% off
9:LC
Backlight 0 = Off, 1 = On (only on demand)
Clock Format 0 = 24 hr, 1 = AM/PM
11:CL
Daylight Saving time change 0 = Off, 1 = Auto
Temperature Display Offset +/1. 5°C
Restore Schedule Defaults 0, 1 = reset
Restore Factory Settings 0, 1 = reset
2 = 5 + 2 day (weekday + weekend schedule)
3 = 1 day (same schedule every day)
OpenTherm Data ID's
NoDescription Settings (default in bold)
Low load control 0 = Off, 1 = On
O T1
Control setpoint 5 - 99°C
OT2
Supply water temperature 5 - 99°C
OT3
Return water temperature 5 - 99°C
OT4
Max. supply water temperature 5 - 99°C
OT5
Hot water temperature 5 - 99°C
OT6
Hot water setpoint 5 - 99°C
OT7
Actual power 0 - 99%
OT8
Water pressure 0.0 - 9.9
OT9
OTC control 0 = Off, 1 = On
O T1 0
OTC curve 4 - 40 (16)
O T11
Room compensation 0 = Off, 1 = On
O T1 2
Conforms to protection requirements of the following directives:
EMC: 2014/30/EU and LVD: 2014/35/EU
ErP: Class VI (+4%), (EU) 811/2013
WEEE Directive 2012/19/EC - Waste Electrical and Electronic Equipment directive
At the end of the product life dispose of the packaging and product in a corresponding recycling
centre. Do not dispose of the unit with the usual domestic refuse. Do not burn the product.
Troubleshooting
What’s happening? What it could mean... How to fix it...
Thermostat
display is blank
Display =
Thermostat shows
heat demand
but boiler doesn't
respond
Honeywell Control Systems Ltd.
Skimped Hill Lane,
Bracknell,
Berkshire
RG12 1EB
www.honeywelluk.com
No power to
heating system
Faulty wiring connection Check wiring at thermostat
Faulty temperature
sensor
Boiler (water) already
at temperature
Faulty wiring connection Check wiring at thermostat
Manufactured for and on behalf of the Environmental & Energy Solutions
Division of Honeywell Technologies Sàrl, ACSE&ES, Z.A., La Pièce 16,
1180 Rolle, Switzerland by its Authorised Representative Honeywell Inc.
© 2016 Honeywell International Inc. | Printed in UK
Check heating system is powered
and boiler terminals
Replace thermostat or check wiring to
remote temperature sensor if fitted
Normal behaviour - wait for
water temperature to drop
and boiler terminals