What if something happens to my heating system? How can I check that the CM61 is working?
See the troubleshooting guide below. If you need assistance after this, call your installer. The CM61 should only be opened or removed by a qualified profes-
sional to prevent possible injury from electric shock.
Incorrect battery cartridge insertion
Batteries need replacing
Display shows flashing
No power to system
Display works but heating does not
Program does not call for heat
CM61 not connected to boiler properly
CM61 not set correctly for your system
Heating switches ON/OFF too slowly
or too quickly
CM61 not set correctly for your system
Temperature swings between too hot
and too cold
Fault in the CM61
Your installer has set a scheduled
Display shows the word 'SERVICE'
maintenance alert period on your CM61 as
a recommendation that your heating system
should receive a routine inspection.
This product and its associated documentation and packaging are protected by various intellectual property rights belonging to Honeywell Inc and its
subsidiaries and existing under the laws of the UK and other countries. These intellectual and property rights may include patent applications, registered
designs, unregistered designs, registered trade marks, unregistered trade marks and copyrights and also include the following UK registration rights:
UK patent application number 98062207.8
UK registered design numbers 2073334, 2073340 and 2073343.
Honeywell Control Systems Ltd.
Arlington Business Park
Bracknell, Berkshire RG12 1EB
User Help Line: 01344 656511
Check batteries are in the battery compartment and that the
paper tab has been pulled out
Check that the batteries have been installed in the correct
Remove battery cartridge and re-insert
Change the batteries as described previously
Check that there is power to the system
to increase the temperature a few degrees
above the current room temperature.The heating should come
on after a few seconds.
Call installer to check electrical connection between the CM61
and the boiler
Remove battery cartridge and re-insert. If the
does not clear itself in a few minutes call the installer
Call your installer to arrange a maintenance visit.
The CM61 and heating system will continue to operate as
What is a Programmable Thermostat?
The Honeywell CM61 is a programmable thermostat which controls your
heating system so that you can have comfortable temperatures when you
are at home and energy savings when you are away.
It is important to understand that the CM61 is not a traditional "ON/OFF"
controller but a "HI / LOW" temperature controller.
This means that to program the heating to go 'OFF' at a particular time a
lower (setback) temperature setpoint is entered which you would choose
to protect you and your home.
What will the CM61 Programmable Thermostat do
Attractive slim styling makes it ideal for location in any suitable
room in your home.
Display Backlight illuminates the display when a key is pressed for
easier viewing in low light conditions.
6 daily independent temperature levels let you set any 6
temperatures from 5 to 30°C to match your daily lifestyle.
Holiday button saves energy by letting you reduce the temperature
for 1 to 99 days while you are on holiday, returning to normal operation
on the day you return.
Memory holds the user program indefinitely so that it is never lost
even if you take the batteries out.
Outside Temperature Sensor (optional accessory) can be fitted to
the CM61 to display the outside temperature.
Remote Temperature Sensor (optional accessory) can be fitted to
the CM61 to control the temperature from another room.
Optimum Start option is a program which ensures that the optimum
temperature conditions are achieved at the required times as
described below (not available on T6661B1040).
What is Optimum Start?
Optimum Start is an Energy Efficiency Feature that adjusts the start time
of your heating system depending upon how cold it is.
On cold days your Heating will be started earlier to ensure that your home
is warm when you get up and on warmer days the heating system will be
started later to save energy.
So, if the Optimum Start Feature is used, the time / temperature settings
which are entered into the CM61 are when you want to be warm by and
not when you want the heating to start. (not available on T6661B1040)