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Thermostat T4M, wired, modulating via OpenTherm output

Product Description

The Honeywell Home T4/T4M/T4R are designed to provide automatic time and temperature control of heating in domestic or light commercial premises.

  • T4: compatible with 24-230V on/off appliances such as gas boilers, combi-boilers and heat pump, wired on the wall installations.
  • T4R: compatible with 24-230V on/off and OpenTherm(R) appliances such as gas boilers, combi-boilers and heat pump, for wireless installations. Exists of a Thermostat and a Receiver box.
  • T4M: compatible with OpenTherm(R) appliances, wired on the wall installations

Also works with zone applications but not with electric heating (240V). The solution is designed with the installer in mind and includes a Receiver module with mounting options for directly on the wall or on a wall box. Wiring can be from below or from the back by lifting the terminal platform, which makes installation quick and easy. The thermostat has a large and clear fix segment Display with backlight, simple programming philosophy all to make it easier to install and very user friendly. The T4 product line is ideal for consumers who want to control their comfort remotely with a modern design, simple to program and easy to use product.

Technical Properties

Modes of operation

Off mode(frost protection), manual mode, following schedule, timed override, temporary override

Control functions

Multizone Time and temperature

Heating /Cooling application Heating only
Time setting resolution

15 minutes

Programmed on/off periods per day 4/6
Holiday mode Yes
Optimisation Yes
Temperature setpoints per day

user selectable 

Heat anticipator Yes
  • EMC:2014/30/EU
  • LVD: 2014/35/EU
  • R and TTE: 1999/05/EC
  • Wire access: From back via large wall box opening
  • WEEE: 2012/19/EU
  • Wireless LAN: IEEE 802.11b,g,n
  • RF communication: ISM 868.0-870.0 MHz Receiver Category 2
ErP Class V
Temp. element place internal
Temp. setpoint range 5 ... 35 oC
Temperature control accuracy 0,5 oC
Setpoint blocking Yes
Setpoint limiting Yes
Control output signal

Switching volt free relay and OpenTherm(R)

Display functions

Fix segment display

Earthing double insulated
Housing (HxWxD) 97 mm | 136 mm | 28 mm
Protection class


Colour White
Terminal max. wire size 1,5 mm2
Battery life


Power source


Memory back-up


Ambient temperature 0 ... 40 oC
Default time display format 24 h
Product description

T4M Wired OpenTherm(R)Thermostat

  • Minimalistic and modern design makes it easy to blend in any type of homes
  • Table stand or wall mounted thermostat options to fit new and replacement installations
  • Backlight for easier viewing in all light conditions
  • Factory programmed daily, weekly or 5+2 default heating schedule
  • Schedule options with 4 or 6 independent set-points to suit comfort needs
  • Set-point temperature always displayed
  • OFF position has an integral frost protection setting at minimum 5 C so that pipes in the house will never freeze
  • Alert messages to assist in fault finding
  • Timed override function allows to hold a targeted setpoint for 1 or 2 hours
  • Away mode allows to reduce the temperature for a period of 1 to 99 days
  • Automatic time clock adjustment for Daylight Saving Time
  • Receiver box with clear LED indication and override button
  • On/Off or OpenTherm (T4R/T4M) compatible control
  • A flip up wiring platform for easy wiring
  • User menu allows extra functions to be set at the discretion of the user: Heating schedule, Date and time setting, Optimisation, Lock function, OpenTherm(R) alerts (T4M only)
  • Installer menu allows extra functions to be set at the discretion of the installer to match the homeowners applications and needs: Language selection, Cycle rate, Upper/Lower set point limit adjustment, Minimum ON time, Daily, weekly or 5+2 schedule Option, 4 or 6 periods a day, Wired remote sensor, Fail safe mode, Clock Format, Daylight saving time change (DST), Temperature display Offset, Factory reset, Binding (T4R only)