Honeywell CM721 Programmable Room Thermostat User Guide
- June 9, 2024
- Honeywell
Table of Contents
- Description
- Features
- SETTING-UP THE CM721
- Modifying the Heating Program
- OPERATING THE CM721
- FAQ’s
- TROUBLESHOOTING THE CM721
- Description
- Features
- SETTING-UP THE CM727
- PROGRAMMING THE CM727
- OPERATING THE CM727
- Using the Features’
- TROUBLESHOOTING THE CM727
- WHAT IS A PROGRAMMABLE ROOM THERMOSTAT?
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
Honeywell CM721 Programmable Room Thermostat User Guide
Description
The Honeywell CM721 is a programmable room thermostat designed to control your heating system efficiently, providing comfortable temperatures when you are at home and energy savings when you are away. The following instructions explain how to program and use the thermostat to provide the most home comfort at the least cost.
Features
- Ergonomic user interface featuring an ‘OK-button’.
- Large LCD (Liquid Crystal Display) Screen.
- 4 independent temperature levels (from 5°C to 35°C).
- Automatic Summer/Winter Time Change.
- Optimum Start to achieve the right temperature at the right time.
- Built-in Memory holds the user program indefinitely
Controls Layout
- LCD Screen
- Battery Low Indicator
- Time Display
- Burner On Indicator
- Temperature Display
- Temperature Change Buttons
- Temperature Enquiry Button
- Operating Mode Buttons
- Green OK Button
- Battery Compartment
- Battery Cover
- Program Buttons
- Time Change Buttons
- Set Date Button
SETTING-UP THE CM721
This section shows you how to setup and run the thermostat in 3 simple steps:
STEP 1: Installing the Batteries
Note: Please follow the instructions in this section only if the
thermostat screen is blank (no symbols or digits are displayed). If the room
temperature is already displayed move on to Step 2: Setting the Date and Time.
To install the Batteries:
a. Lift up the front cover of the thermostat to reveal the battery cover
and product controls.
b. Remove the battery cover by pressing down and sliding out.
c. Insert the 2 x AA LR6 Alkaline Batteries supplied with the thermostat,
ensuring the correct orientation (see ‘Controls Layout’ on page 2).
d. After a short pause the thermostat will display information on the
screen and is now ready for use.
e. Replace the battery cover by sliding it firmly back into the front of
the thermostat.
STEP 2: Setting the Date and Time
To set the Date and Time:
a. Press the DATE button to begin setting the date. When you set the date
for the first time after the batteries are inserted, the display will show:
Press the or buttons to set the current day of the month (e.g. d 01 = 1st day
of the month) then press the green button to confirm.
b. Press the or buttons to set the current month of the year (e.g. m 01 = January) then press the green button to confirm.
c. Press the or buttons to set the current year (e.g. yr 06 = 2006) then press the green button to confirm. The date is now stored.
d. Use the or buttons to set the correct time then press the green button to confirm. Each press of the buttons will change the time by one minute and holding them down will change the time slowly at first and get progressively quicker.
Note: If this mode is entered accidentally then press theAUTO, MAN or OFF buttons to exit
STEP 3: Running the Built-in Heating Program
The thermostat is now ready for operation. Press the AUTO button and the
built-in heating program will start running.
Note: The built-in heating program has been designed to provide normal
comfort requirements, but if you want to customise the settings please see the
next section ‘Programming the CM721
The Built-in Heating Program
The built-in heating program has 4 temperature level changes that can be set
between 3.00am and 2.50am the following day – allowing you to maintain the
evening temperature after midnight. Each temperature level can be set between
5°C and 35°C, and adjusted in 0.5°C increments. The factory default program
for heating is as follows.
Period | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Time | 6:30 | 8:00 | 18:00 | 22:30 |
Temperature | 21°C | 18°C | 21°C | 16°C |
Reviewing the Heating Program
To review or edit the heating program use the PROGRAM or buttons to navigate
between the 4 individual programming periods.
Modifying the Heating Program
To change the heating program:
a. Press either of the PROGRAM or buttons to enter the programming
mode. The time / temperature settings for period 1 will be flashing as shown.
The active period is highlighted by a flashing square around the numbers at
the bottom of the screen.
b. To adjust the period start time use the or buttons, the display will
stop flashing and the ‘OK?’ indicator will be displayed. Holding the button
down will change the time quickly.
Note: If you are pressing the or buttons and the display flashes the next
period, it means the next period will be pushed forward.
c. Once the required time is reached press the green button to confirm.
Note : If the original time setting did not require adjustment press the
green button to move to step ‘d’.
d. The temperature setting for period 1 will now be flashing. To adjust
this press the or buttons and confirm the setting again by pressing the green
button.
e. The next time and temperature period will now be active. Adjust this
by repeating steps b – d above until all 4 periods are set or press the AUTO
button to run the program as set, at any time.
Disabling / Enabling Time Periods
The thermostat has 4 periods that can be programmed, but you may not need all
of these switch points for your heating requirements. Therefore, any period
from 2 to 4 can be removed from (or returned to) the heating program profile.
To disable or enable time periods:
a. To disable unwanted periods go to the desired period ( 2 to 4 ) using
the PROGRAM or buttons to navigate, ensure the correct period is highlighted
with the flashing square symbol. Press and hold the button for at least 2
seconds and the display will indicate the period has been removed from the
program.
b. To enable periods again follow the same procedure as above, navigating
to the already disabled period. To enable this period again press and hold the
button for at least 2 seconds.
OPERATING THE CM721
Choosing the Operating Mode
The thermostat can operate in three different modes: Automatic, Manual or Off.
To set the operating mode press either of the AUTO, MAN or OFF buttons. The
screen indicates which mode is currently active by displaying AUTO, MAN or
OFF.
- AUTO (automatic) mode sets the thermostat to follow the built-in temperature program (default or personalised). Operating the thermostat in this mode is the best way to maintain a high level of temperature comfort whilst maximising your energy savings.
- MAN (manual) mode sets the thermostat to act as a simple thermostat with a fixed setpoint throughout the day. The setpoint can be adjusted from 5°C to 35°C by using the or buttons. The thermostat will continue to maintain this temperature until another operating mode or temperature is selected.
- OFF mode sets the thermostat to control to a minimum temperature setting of 5°C (default) that acts as a frost protection measure for your home.
During Normal Operation
-
Temperature Enquiry
In AUTO, MAN and OFF operating modes the thermostat will display the current room temperature. To review the programmed ‘target’ temperature (the temperature which the thermostat is trying to maintain) press the button. This ‘target’ temperature value will be displayed flashing for 5 seconds before returning to the current room temperature value. -
Temperature Override
During normal operation (AUTO mode) the programmed temperature can be adjusted manually by pressing the or buttons or the button. The ‘target’ temperature will be displayed and flash for 5 seconds – during this time the or buttons can be used to modify the set value.
Note: This temperature override is cancelled at the next programmed temperature change.
Adjusting the Time
To adjust only the time during normal operation use the or buttons to adjust
the time and press the green button again to confirm any changes.
Using the Special Features
-
SERVICE indicator
Note: This option only works if activated by your installer. The ‘SERVICE’ indicator is displayed at set intervals as a reminder that your heating system requires a routine check. Please call your installer to arrange a maintenance visit. The ‘SERVICE’ indicator will remain on the display of the CM721 until it is either reset or disabled by your installer. The CM721 and heating system will continue to operate as normal. -
Automatic Summer/Winter Time Change
The CM721 has a built-in Automatic Summer/Winter Time Change feature that will automatically adjust the clock forward or backward by one hour for ‘Daylight Saving Time’. This is carried out on the last Sunday of March and October each year. -
Optimum Start
Optimum Start is a program which ensures that the optimum temperature conditions are achieved at the required times. This is an Energy Efficiency feature that adjusts the start time of your heating system depending upon how cold it is. For example, on cold days your heating system will be started earlier to ensure that your home is warm when you get up (at the target temperature) and on warmer days the heating system will be started later to save energy. So, if the Optimum Start Feature is used, then the time / temperature settings which are entered into the thermostat should be set to when you want to be warm by and not when you want the heating system to start.
FAQ’s
How do I change the batteries on the thermostat when they run out?
The thermostat constantly monitors the battery power level, which typically
lasts for about 2 years before needing replaced. When the power is running low
a flashing symbol will be displayed on the screen. To change the batteries
follow the steps in the above section (‘STEP 1: Installing the Batteries’ on
page 3), replacing the used batteries with new ones in Step c.
Note: While changing the batteries your program settings will be stored
but you may need to adjust the time settings to be correct.
How do I set one temperature for the whole day?
To operate as a simple thermostat with one temperature throughout the day, select the manual operating mode by pressing the MAN button. Adjust the temperature by pressing the or buttons – this can be set anywhere from 5°C to 35°C in 0.5°C steps. The thermostat will continue to maintain this temperature until another operating mode is selected or the temperature is adjusted.
BDR91 Relay Box Controls Layout
The relay box will normally be found mounted close to the boiler.
What does it mean when the BDR91 relay box green LED is ON?
The green LED indicates normal operation of the radio frequency system. When
the green LED is ON the boiler is also ON. When the LED is OFF the boiler is
OFF.
When do I need to use the push button?
You should use the push button to control your boiler only when the RF
communication is lost (see the Troubleshooting Guide).
TROUBLESHOOTING THE CM721
Symptom | Remedy |
---|---|
Blank Display (Power Loss). | Check batteries are installed by removing the |
battery cover.
Check batteries have been installed in the correct orientation.
Replace the batteries.
Display shows flashing symbol.| The batteries in the thermostat are low on
power- Replace the batteries.
Display shows symbol.| A fault has occurred in your heating system. Remove
and re-insert the batteries.
If the symbol does not clear after a few minutes contact your installer.
Display shows the word ‘ SERVICE ‘| Your installer has set a scheduled
maintenance alert period on your CM721 as a recommendation that your heating
system should receive a routine inspection.
Call your installer to arrange a maintenance visit.
Note: The CM721 and heating system will continue to operate as
normal.
BDR91 red LED is constantly on or flashing| RF communication lost due to the
wrong location of the room unit – Hook the room unit back on the wall bracket
where RF communication was reliable.
Call installer
NOTE: You can control the boiler manually when the RF communication
is lost: Press the BDR91 push button to switch the boiler on and off. When the
green LED is on – the boiler is on.
Description
The Honeywell CM727 is a programmable room thermostat designed to control your heating system efficiently, providing comfortable temperatures when you are at home and energy savings when you are away. The following instructions explain how to program and use the thermostat to provide the most home comfort at the least cost.
Features
- Ergonomic user interface featuring an ‘OK-button’.
- Large LCD (Liquid Crystal Display) Screen.
- 7-day heating program to match your lifestyle, whilst maximising energy savings.
- 4 independent temperature levels per day (from 5°C to 35°C).
- Holiday button saves energy by letting you reduce the temperature for 1 to 99 days.
- Automatic Summer/Winter Time Change.
- Optimum Start to achieve the right temperature at the right time.
- Built-in Memory holds the user program indefinitely.
Controls Layout
- LCD Screen
- Battery Low Indicator
- Time Display
- Burner On Indicator
- Day Indicator
- Temperature Display
- Temperature Change Buttons
- Temperature Enquiry Button
- Operating Mode Buttons
- Green OK Button
- Battery Compartment
- Battery Cover
- Holiday Function Button
- Program Buttons
- Copy Day Button
- Set Date/Day Button
- Time Change Buttons
SETTING-UP THE CM727
This section shows you how to setup and run the thermostat in 3 simple steps:
STEP 1: Installing the Batteries
Note : Please follow the instructions in this section only if the
thermostat screen is blank (no symbols or digits are displayed). If the room
temperature is already displayed move on to Step 2:
Setting the Date and Time.
To install the Batteries:
a. Lift up the front cover of the thermostat to reveal the battery cover
and product controls.
b. Remove the battery cover by pressing down and sliding out.
c. Insert the 2 x AA LR6 Alkaline Batteries supplied with the thermostat,
ensuring the correct orientation (see ‘Controls Layout’ on page 8).
d. After a short pause the thermostat will display information on the
screen and is now ready for use.
e. Replace the battery cover by sliding it firmly back into the front of
the thermostat.
STEP 2: Setting the Date and Time
To set the Date and Time:
a. Press the DATE/DAY button to begin setting the date. When you set the
date for the first time after the batteries are inserted, the display will
show: Press the or buttons to set the current day of the month (e.g. d 01 =
1st day of the month) then press the green button to confirm.
b. Press the or buttons to set the current month of the year (e.g. m 01 = January) then press the green button to confirm.
c. Press the or buttons to set the current year (e.g. yr 06 = 2006) then press the green button to confirm. The date is now stored and the Day Indicator will be displayed under the current day of the week (e.g. 1 = Monday, 2 = Tuesday, etc.)
d. Use the or buttons to set the correct time then press the green button to confirm. Each press of the buttons will change the time by one minute and holding them down will change the time slowly at first and get progressively quicker.
Note: If this mode is entered accidentally then press the AUTO, MAN or OFF buttons to exit.
STEP 3: Running the Built-in Heating Program
The thermostat is now ready for operation. Press the AUTO button and the
built-in heating program will start running. Note: The built-in heating
program has been designed to provide normal comfort requirements, but if you
want to customise the settings please see the next section ‘Programming the
CM727’.
The Built-in Heating Program
The built-in heating program has 4 temperature level changes per day that can
be set between 3.00am and 2.50am the following day – allowing you to maintain
the evening temperature after midnight. Each temperature level can be set
between 5°C and 35°C, and adjusted in 0.5°C increments. The factory default
program for heating is as follows.
Monday to Friday (Day 1 to 5)
Period | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Time | 6:30 | 8:00 | 18:00 | 22:30 |
Temperature | 21°C | 18°C | 21°C | 16°C |
Saturday & Sunday (Day 6 & 7)
Period | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Time | 8:00 | 10:00 | 18:00 | 23:00 |
Temperature | 21°C | 21°C | 21°C | 16°C |
Reviewing the Heating Program
To review or edit the heating program use the PROGRAM or buttons to navigate
between the 4 individual programming periods for that day. Use the DATE/DAY
button to step through each day of the week, so the complete 7 day heating
program can be reviewed or edited.
Modifying the Heating Program
To change the heating program:
a. Press either of the PROGRAM or buttons to enter the programming mode.
The time / temperature settings for period 1 on Monday (Day 1) will be
flashing as shown. The active period is highlighted by a flashing square
around the numbers at the bottom of the screen and the selected day is shown
with the day indicator.
b. To adjust the period start time use the or buttons, the ‘OK?’
indicator will be displayed to confirm the change. Holding the button down
will change the time quickly.
Note: If you are pressing the or buttons and the display flashes the next
period, it means the next period will be pushed forward.
c. Once the required time is reached press the green button to confirm.
Note: If the original time setting did not require adjustment press the
green button to move to step ‘d’.
d. The temperature setting for period 1 on Monday (Day 1) will now be
flashing. To adjust this press the or buttons and confirm the setting again by
pressing the green button.
e. The next time and temperature period will now be active. Adjust this
by repeating steps b – d above until all 4 periods are set for Monday or press
the AUTO button to run the program as set, at any time.
You now have a choice of how to set the program for the next day:
PROGRAMMING THE CM727
f. i) Press the COPY DAY button to copy Monday’s program into Tuesday.
The display will go blank apart from the ‘non flashing’ day indicator, which
indicates the day copied and the ‘flashing’ target day to copy the program to.
To accept this day press the green button. To select a different target day
press the DATE/DAY button until the ‘flashing’ day indicator is under the
required day, then accept it by pressing the green button. Note: Once the
target day is confirmed it becomes the day that is copied if the COPY DAY
button is pressed again. OR
ii) Press the DATE/DAY button to move the day indicator to Tuesday (Day
2). The program for that day can then be adjusted by following steps b to e.
Programs for the remaining days can be set in the same way, using the DATE/DAY
button to move to the next day.
To exit the programming mode select the desired operating mode by pressing the
AUTO, MAN or OFF buttons. Note: To run the adjusted program select the AUTO
mode.
Disabling / Enabling Time Periods
The thermostat has 4 periods each day that can be programmed, but you may not
need all of these switch points for your heating requirements. Therefore, any
period from 2 to 4 can be removed from (or returned to) the heating program
profile.
To disable or enable time periods:
a. To disable unwanted periods go to the desired period ( 2 to 4 ) using
the PROGRAM or buttons to navigate, ensure the correct period is highlighted
with the flashing square symbol. Press and hold the button for at least 2
seconds and the display will indicate the period has been removed from the
program.
b. To enable periods again follow the same procedure as above, navigating
to the already disabled period. To enable this period again press and hold the
button for at least 2 seconds.
OPERATING THE CM727
Choosing the Operating Mode
The thermostat can operate in three different modes: Automatic, Manual or Off.
To set the operating mode press either of the AUTO, MAN or OFF buttons. The
screen indicates which mode is currently active by displaying AUTO, MAN or
OFF.
- AUTO (automatic) mode sets the thermostat to follow the built-in temperature program (default or personalised). Operating the thermostat in this mode is the best way to maintain a high level of temperature comfort whilst maximising your energy savings.
- MAN (manual) mode sets the thermostat to act as a simple thermostat with a fixed setpoint throughout the day. The setpoint can be adjusted from 5°C to 35°C by using the or buttons. The thermostat will continue to maintain this temperature until another operating mode or temperature is selected.
- OFF mode sets the thermostat to control to a minimum temperature setting of 5°C (default) that acts as a frost protection measure for your home.
Using the Features’
During Normal Operation
-
Temperature Enquiry
In AUTO, MAN and OFF operating modes the thermostat will display the current room temperature. To review the programmed ‘target’ temperature (the temperature which the thermostat is trying to maintain) press the button. This ‘target’ temperature value will bedisplayed flashing for 5 seconds before returning to the current room temperature value. -
Temperature Override
During normal operation (AUTO mode) the programmed temperature can be adjusted manually by pressing the or buttons or the button. The ‘target’ temperature will be displayed and flash for 5 seconds – during this time the or buttons can be used to modify the set value.
Note: This temperature override is cancelled at the next programmed temperature change.
Adjusting the Time
To adjust only the time during normal operation use the or buttons to adjust
the time and press the green button again to confirm any changes.
Using the Special Functions
HOLIDAY Function
The holiday function allows you to set a constant temperature (default = 10°C)
for a specified number of days (from 1 – 99 days). This lets you save energy
and related costs when you are away from home, but resumes normal operation on
the day of your return.
To set the Holiday function:
a. Ensure the thermostat is running in AUTO or MAN operating modes.
b. Press the holiday button to display the holiday days counter and
temperature setting, along with the holiday indicator .
c. Press the or time buttons to set the holiday time (1 – 99 days) and
press the green button to confirm.
d. Press the or buttons to set the holiday temperature (5°C – 35°C) and
press the green button to confirm.
Using the Special Features
-
SERVICE indicator (optional)
Note: This option only works if activated by your installer. The ‘SERVICE’ indicator is displayed at set intervals as a reminder that your heating system requires a routine check. Please call your installer to arrange a maintenance visit. The ‘SERVICE’ indicator will remain on the display of the CM727 until it is either reset or disabled by your installer. The CM727 and heating system will continue to operate as normal. -
Automatic Summer/Winter Time Change
The CM727 has a built-in Automatic Summer/Winter Time Change feature that will automatically adjust the clock forward or backward by one hour for ‘Daylight Saving Time’. This is carried out on the last Sunday of March and October each year. -
Optimum Start
Optimum Start is a program which ensures that the optimum temperature conditions are achieved at the required times. This is an Energy Efficiency feature that adjusts the start time of your heating system depending upon how cold it is. For example, on cold days your heating system will be started earlier to ensure that your home is warm when you get up (at the target temperature) and on warmer days the heating system will be started later to save energy. So, if the Optimum Start Feature is used, then the time / temperature settings which are entered into the thermostat should be set to when you want to be warm by and not when you want the heating system to start.
How do I change the batteries on the thermostat when they run out?
The thermostat constantly monitors the battery power level, which typically
lasts for about 2 years before needing replaced. When the power is running low
a flashing symbol will be displayed on the screen. To change the batteries
follow the steps in the above section (‘STEP 1: Installing the Batteries’ on
page 3), replacing the used batteries with new ones in Step c.
Note : While changing the batteries your program settings will be stored
but you may need to adjust the time settings to be correct.
How do I set one temperature for the whole day?
To operate as a simple thermostat with one temperature throughout the day,
select the manual operating mode by pressing the MAN button. Adjust the
temperature by pressing the or buttons – this can be set anywhere from 5°C to
35°C in 0.5°C steps. The thermostat will continue to maintain this temperature
until another operating mode is selected or the temperature is adjusted.
BDR91 Relay Box Controls Layout
The relay box will normally be found mounted close to the boiler.
What does it mean when the BDR91 relay box green LED is ON?
The green LED indicates normal operation of the radio frequency system. When
the green LED is ON the boiler is also ON. When the LED is OFF the boiler is
OFF.
When do I need to use the push button?
You should use the push button to control your boiler only when the RF
communication is lost (see the Troubleshooting Guide).
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. Honeywell reserves the right to modify this document, product and functionality without notice. This document replaces any previously issued instructions and is only applicable to the product(s) described. This product has been designed for applications as described within this document. For use outside of the scope as described herein, refer to Honeywell for guidance. Honeywell cannot be held responsible for misapplication of the product(s) described within this document. Manufactured for and on behalf of the Environmental and Combustion Controls Division of Honeywell Technologies Sàrl, ACS-ECC EMEA, Z.A. La Pièce 16, 1180 Rolle, Switzerland by its Authorised Representative Honeywell Inc.
TROUBLESHOOTING THE CM727
Symptom | Remedy |
---|---|
Blank Display (Power Loss). | Check batteries are installed by removing the |
battery cover. Check batteries have been installed in the correct
orientation. Replace the batteries.
Display shows flashing symbol.| The batteries in the thermostat are low on
power- Replace the batteries.
Display shows symbol.| A fault has occurred in your heating system. Remove
and re-insert the batteries. ** If the symbol does not clear after a few
minutes contact your installer.
Display shows the word ‘ SERVICE ‘| Your installer has set a scheduled
maintenance alert period on your CM727 as a recommendation that your heating
system should receive a routine inspection. ** Call your installer to
arrange a maintenance visit. **Note: The CM727 and heating system
will continue to operate as normal.
BDR91 red LED is constantly on or flashing| RF communication lost due to the
wrong location of the room unit – Hook the room unit back on the wall bracket
where RF communication was reliable. **Call installer **NOTE:**
You can control the boiler manually when the RF communication is lost: Press
the BDR91 push button to switch the boiler on and off. When the green LED is
on – the boiler is on.
WHAT IS A PROGRAMMABLE ROOM THERMOSTAT?
an explanation for householders A programmable room thermostat is both a programmer and a room thermostat. A programmer allows you to set ‘On’ and ‘Off’ time periods to suit your own lifestyle. A room thermostat works by sensing the air temperature, switching on the heating when the air temperature falls below the thermostat setting, and switching it off once this set temperature has been reached. So, a programmable room thermostat lets you choose what times you want the heating to be on, and what temperature it should reach while it is on. It will allow you to select different temperatures in your home at different times of the day (and days of the week) to meet your particular needs. Turning a programmable room thermostat to a higher setting will not make the room heat up any faster. How quickly the room heats up depends on the design of the heating system, for example, the size of boiler and radiators.
Neither does the setting affect how quickly the room cools down. Turning a programmable room thermostat to a lower setting will result in the room being controlled at a lower temperature, and saves energy. The way to set and use your programmable room thermostat is to find the lowest temperature settings that you are comfortable with at the different times you have chosen, and then leave it alone to do its job. The best way to do this is to set low temperatures first, say 18°C, and then turn them up by one degree each day until you are comfortable with the temperatures. You won’t have to adjust the thermostat further. Any adjustments above these settings will waste energy and cost you more money. If your heating system is a boiler with radiators, there will usually be only one programmable room thermostat to control the whole house. But you can have different temperatures in individual rooms by installing thermostatic radiator valves (TRVs) on individual radiators. If you don’t have TRVs, you should choose a temperature that is reasonable for the whole house. If you do have TRVs, you can choose a slightly higher setting to make sure that even the coldest room is comfortable, then prevent any overheating in other rooms by adjusting the TRVs. The time on the programmer must be correct. Some types have to be adjusted in spring and autumn at the changes between Greenwich Mean Time and British Summer Time. You may be able to temporarily adjust the heating programme, for example, ‘Override’, ‘Advance’ or ‘Boost’. These are explained in the manufacturer’s instructions. Programmable room thermostats need a free flow of air to sense the temperature, so they must not be covered by curtains or blocked by furniture. Nearby electric fires, televisions, wall or table lamps may prevent the thermostat from working properly
Honeywell Control Systems Ltd.
Arlington Business Park,
Bracknell
Berkshire
RG12 1EB
Technical Help Desk: 08457 678999
www.honeywelluk.com