WORCESTER Comfort II RF Programmable Room Thermostat Installation and operating instructions

NOTICE indicates a situation that could result in damage to property or equipment.
CAUTION indicates a situation that could result in minor to medium injury.
WARNING indicates a situation that could result in severe injury or death.
DANGER indicates a situation that will result in severe injury or death.

Important information
This symbol indicates important information where there is no risk to people or property

Additional symbols

Symbol	Explanation
▶	Step in an action sequence
à	Cross-reference to another part of the document
•	List entry
–	List entry (second level)

Abbreviations

CH	=	Central Heating
DHW	=	Domestic Hot Water
RF	=	Radio Frequency
DST	=	Daylight Savings Time
BST	=	British Summer Time
GMT	=	Greenwich mean time
RPB	=	Rotary Push Button

Definitions (DST/BST)
Daylight Saving Time (DST) and British Summer Time (BST) begin on the last Sunday in March at 1:00 am GMT and clocks are put forward by one hour. British Summer Time (BST) ends on the last Sunday in October at 2:00 am BST and the clocks are put back by one hour.

General safety instructions
These installation instructions are intended for heating engineers and electricians.

Read any installation instructions (boiler, heating controls, etc.) carefully before starting the installation.
Observe the safety instructions and warnings.
Observe national and regional regulations, technical rules, and guidelines.
Record all work carried out.

Appliance operation
This appliance can be used by children aged 8 years and above and persons with reduced physical, sensory or mental capabilities or lack of experience and knowledge if they have been given supervision or instruction concerning the use of the appliance in a safe way and understand the hazards involved. Children shall not play with the appliance. Cleaning and user maintenance shall not be made by children without supervision. (BS EN 60335-1 2012)

Installation, commissioning, and servicing
Installation, commissioning, and servicing must only be carried out by a competent engineer.

Only use original spares.

Electrical work
Electrical work must only be carried out by a qualified electrician.

Before starting electrical work:
- Isolate the mains electrical supply and secure it against unintentional re-connection.
- Check for zero voltage.
Also, observe connection diagrams of other system components.

Handover to the user
When handing over, instruct the user on how to operate the heating system and inform him about its operating conditions.

Explain how to operate the heating system and draw the user’s attention to any safety-relevant action.
Explain that modifications and repairs must only be carried out by an authorized contractor.
Advise the user to have the system serviced annually by a competent engineer.
Leave this instruction manual with the user or at the appliance.

Comfort II RF

The Comfort II RF comprises a wall-mounted twin-channel RF programmable room thermostat and a boiler or wall-mounted RF receiver.

Programmable room thermostat
The wall-mounted unit is a twin-channel RF Programmable room thermostat. The Programmable room thermostat is for central heating and hot water control with modulating/enhanced load-compensating boiler regulation. Up to six time and temperature periods can be set to control central heating as well as up to three ON and Off times to control hot water. This enhance load-compensating function enables an intelligent conversation with the boiler to achieve the desired room temperature in the most efficient way possible. To help save the customer money by burning less fuel, and to minimize room temperature “overshoot” the boiler’s burner may stop firing just prior to the desired room temperature being reached. This behavior including reduced radiator temperature is perfectly normal. The customer should simply set a temperature on the thermostat that they are comfortable with and allow the room thermostat and boiler to do their work. All programming and adjustment is conveniently done from the Programmable room thermostat making the Comfort II RF an excellent solution if your boiler is not easily accessible. The unit has user and installer menus to allow the setting of the temperatures, time programs, monitoring of system information, setting current time/date, daylight savings, maintenance schedules, and pairing the device with the Receiver

1	Display	Temperature, time, date, CH and HW program selection, fault codes, menu symbols and operational symbols
2	Hot water program selection	ON, OFF, AUTO, ONCE, NA (NA displayed on additional Room stats in multiple CH zone applications)
3	Hot water (HW) program advance button/user menu selection button	Only functional in AUTO mode. Pressed once, advances the timer to the next programmed ON or OFF time, pressed again, returns to the current program. Hold the button down for more than 3 seconds to enter the user menu program
4	Rotary push button knob	Turn or press to select or confirm settings
5	Central heating program advance button / Return button	Only functional in AUTO mode. Pressed once, advances the timer to the next programmed ON or OFF time, pressed again, returns to the current program. When in the menu functions this button returns to next higher level
6	Central heating program selection	ON, OFF, AUTO

Receiver

This unit is only used in conjunction with the Programmable room thermostat. The unit can be mounted in the boiler fascia, refer to your boiler Installation, Commissioning and Servicing instruction manual for fitting instructions. The unit can also be wall mounted and hard-wired to the boiler via the EMS BUS connections.

Comfort II RF installation

Refer to the boiler’s Installation, Commissioning and Servicing instruction manual for information on the boiler. Refer to this manual for detailed information on installing and using the Comfort II RF. A brief overview of the Comfort II RF installation procedure is listed below:

Isolate the boiler
Remove any panels or casings required to gain access to the control panel
Mount the Receiver (boiler fascia or a suitable wall location using the optional Wall Mounting Plate Kit, this will require wiring between the boiler EMS BUS connections and Wall Mounting Plate)
Turn the boiler on
Insert batteries in the Programmable Room thermostat
Set time and date on the Programmable room thermostat
The units will automatically connect to each other
Ensure that the signal strength is adequate at the Programmable room thermostat before mounting in a suitable reference room  Section 5.1.4 Info – Signal strength on page 12

The Comfort II RF Programmable room thermostat consists of two units: the Receiver that mounts into the boiler fascia or, with an optional wall mounting kit, onto the wall and the Programmable room thermostat which mounts on a wall in a suitable reference room

Receiver mounting
There are two methods of mounting the Receiver:

In the boiler fascia
On the wall (optional wall mounting kit 7 733 600 039)

If your boiler is mounted remotely i.e. in the loft or an outbuilding, you may want the Receiver to be conveniently located for easy access

Boiler fascia mounted
Refer to your boiler’s Installation, Commissioning and Serving instruction manual for mounting the Receiver into the boiler fascia.

Wall mounted
Choose a convenient wall location, approximately 1.2 meters from the floor, to mount the Timer. The Receiver is a radio frequency (RF) device and as such is flexible for positioning.

EMS connection

Run a two-core cable from the boiler to the Receiver location. Use an electrical cable with a minimum rating of H05VV-F. For cable runs up to:

100 meters, use 0.50mm2 conductor cross-sectional area
300 meters, use 1.5mm2 conductor cross-sectional area

Connect the cable to the EMS bus point connections on the boiler control circuit board, refer to the Installation, Commissioning and Servicing instruction manual for your boiler to locate the EMS connections.

Optional wall mounting kit

Using the wall plate as a template, mark the position of the mounting screws. The optional wall mounting kit contains:

2 x countersunk screws
2 x plastic wall plugs
Wall plate
Top retainer
Drill two holes to suit the size and depth of the wall plugs
Fit the wall plugs
Feed the two core cable through the back of the wall plate
Fit the wall plate [1], ensuring that it is level and tighten the screws to secure
Connect the two core cable to the terminal block, one coreto each outer connection, ignore the middle connection
Engage the four clips on the back of the Receiver [2] with the four slots on the wall plate as shown in Figure 4
Push the Receiver down into the body of the wall plate to secure
- Engage the tabs on the top retainer [3] into the slots on the wall plate [1] and push down onto the Receiver to secure

Programmable room thermostat mounting
Before mounting the Room thermostat wall plate, fit batteries in the Room thermostat unit and turn the boiler on to identify a location that offers a good RF signal.

Fitting the batteries

Ensure that the batteries are the correct type (LR6/AA) and oriented as shown in Figure 5
Insert the batteries ensuring that the positive + end of the battery is inserted into the positive + terminal of the holder.

Room Thermostat positioning
Before mounting the room Programmable room thermostat on the wall, it is good practice to find a position that affords good signal strength.

Signal strength

Press the menu button for more than three seconds.
Turn the knob to select Info and press the knob.
Turn the knob to select Signal strength and press the knob to enter the function.
The signal strength is displayed as a number from 0 to 10 in the area where the temperature is normally displayed

0	=	no signal
1 – 3	=	weak signal
4 – 6	=	acceptable signal
7 – 10	=	very good signal

Wall mounting plate
To remove the wall mounting plate:

Insert a suitable flat-bladed screwdriver into the slot on the bottom edge of the thermostat
Twist the screwdriver and gently release the bottom catch.
Remove the wall plate from the programmable room thermostat

Wall mounting

The Programmable room thermostat is a radio frequency device and as such is flexible for positioning, there is no requirement to hard wire the device. The thermostat requires free air flow and should be mounted in an open area and not obscured by curtains or furniture. The thermostat should be mounted no closer than 300mm to metal objects, including metal wall boxes. Mount the thermostat on a wall that is not subject to direct sunlight or draughts, preferably on an inside wall at 1.2 meters above the floor. The thermostat must not be directly influenced by radiators or other appliances giving off heat, such as televisions or lamps

Using the wall plate as a template, mark the position of the mounting screws. The wall mounting kit provided with the Programmable room thermostat contains:

2 x countersunk screws
2 x plastic wall plugs
Drill two holes to suit the size and depth of the wall plugs
Fit the wall plugs
Fit the screws, but leave a sufficient amount proud to allow the wall plate to be fitted over the screw heads
Fit the wall plate, ensuring that it is level, and tighten the screws to secure

Operation

Date and time set up

A21 will be displayed at the initial switch-on until the two units have established an RF communication link
Set the current time and date
Hold the menu button down for more than 3 seconds to enter the user menu, turn the knob to select Settings, and press to enter
Refer to section 5.1.5 Settings – Time/ Date for setting the Time and Date, and the clock format
The Programmable room thermostat and Receiver are delivered together and are factory paired, they automatically connect when the system is switched on. There is no need to pair/unpair the units during installation. In the unlikely event that signals issues are suspected refer to the section

The Programmable room thermostat is supplied with factory-set default CH times and temperature periods and DHW ON and OFF times that are shown in the table below. These settings can be reset according to the homeowner’s requirements via the User menu function on the Programmable room thermostat, section 5.1. The times and temperatures can be reset to the factory setting via the User menu section 5.1.5. Settings – Reset all.

06:30		08:30	16:30	22:30
CH	1st	2nd	3rd	4th
CH TEMP	20 °C	16 °C	21 °C	10 °C
DHW	ON	OFF	ON	OFF

Normal operation
During normal operation the display shows:

current room temperature
the operational modes of the central heating and hot water
the current time and day, with am or pm for the 12-hour time format are displayed when the screen is backlit, but are not displayed when the screen dims after 20 seconds of inactivity

Low battery
A battery symbol indicates the batteries require replacing, refer to section 9.1

Burner ON indicator
The symbol is shown when the boiler is firing and heating up, there can be up to a six-minute delay between the boiler indication and the programmer display

Low RF signal strength
The A21 fault code indicates no RF signal, refer to section 5.2 Installer/Radio settings and section 6.2 Pairing/ Unpairing. 5.2.6

Programmable room thermostat
During normal operation the display shows:

The operational mode for the central heating, are either ON, OFF, AUTO, or ADV press the Central heating select button to choose either:
- ON = heating is permanently on
- OFF = heating is permanently off
AUTO = programmed times and temperatures for heating
In the Auto mode, press the Advance button once to move to the next on or off time, and press for a second time to return to the current program
the operational modes for the hot water, are either ON, OFF, ONCE, AUTO or ADV, press the HW select button to choose either:
- ON = hot water is permanently on
- OFF = hot water is permanently off
- ONCE = hot water is on from the first programmed on time to the last programmed off time
- AUTO = programmed times for hot water
In the Auto mode, press the Advance button once to move to the next on or off time, press for a second time to return to the current programme
the current time and day,
am or pm for the 12 hour time format

Graphical indication of the current time/temperature settings, the black markers indicate half hour time periods, and the height of the markers gives an approximation of the temperature setting. The flashing black marker indicates the current time position in the programmed sequence.

Current room temperature
HW operational status
Current day
Current time
Burner ON – display when boiler is heating (can be up to 6 minutes delay)
Frost protection – displayed when boiler is set to OFF
am or pm indication when in the 12 hour clock format
Central heating operational status
Battery condition indicator

Room temperature indication in Auto mode
When the Programmable room thermostat is in Auto mode, pressing the knob once and releasing will display the current desired room temperature setting, and also when the next temperature increase time is scheduled. The example shown below indicates that the room temperature is 15 °C until 16:30 (4:30pm).

Room temperature indication in the On mode
When the Programmable room thermostat is in the On mode, pressing the knob once and releasing will display “Permanently” and the temperature that is permanently set.

Room temperature indication in the Off mode
When the Programmable room thermostat is in the Off mode, pressing the knob once and releasing will display “Permanently”and the temperature of 5 °C. After three seconds the display will revert back to show the actual room temperature and also the frost symbol indicating that if the room temperature goes below 5 °C the boiler will come on and maintain that temperature to prevent freezing.

Setting a new room temperature
Under normal operation the display shows the current room temperature. When the Auto or On mode, turn the knob anti-clockwise to decrease the temperature or clockwise to increase. The new temperature setting will flash for three seconds. The display will briefly show the new temperature up to the next time period change.

Programmable room thermostat settings

There are two levels of settings:

User
Installer

User
Press the menu button for more than three seconds to enter the User setting area of the Timer/programmer. Five icons are shown across the top of the display:

Heating (CH)
Hot Water (HW)
Holiday
Info
Settings

Heating
The top line of the display shows the words Time programs plus flashing arrow heads at each end, this indicates that there are more programs available:

Time programs

Time programs
Select Time programs with the knob, and press to enter

Press the Return button at any time to return to the previous higher level. In the Time program you can set up to 6 time and temperature periods for CH. Using the knob you can select various combinations of days, for example:

Mon to Fri
Sat and Sun
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday

Whether you choose to set the same times for Monday to Friday and different times for Saturday and Sunday or set times for individual days the setting operation is the same.

Select the desired day(s) using the knob
Press the knob to select Time setting 1, this should be the first on time in the morning
The hours flash, turn the knob to select the hours setting
Press the knob to confirm
The minutes flash, turn the knob to select the minutes
Press the knob to confirm
Temp. setting 1 flashes, this will be the temperature that is comfortable for your home during the first time period
Turn the knob to set the required temperature and press the knob to confirm
Time setting 2 hours flash, this will be the time that you want the temperature set lower, maybe while the house is unoccupied
Turn the knob to select the hours setting and press the knob to confirm
The minutes flash, turn the knob to select the minutes and press the knob to confirm
Press the knob to confirm
Temp. setting 2 flashes, this will be the temperature that is set for the second time period, this should be the lowest temperature you want the house to be at while unoccupied
Turn the knob to set the required temperature and press the knob to confirm
Time setting 3 hours flash, this will be the time that the temperature is set to another value, maybe higher because the house is occupied now for the afternoon/evening and you would like your heating on
Repeat the process to set the hours and minutes for Time setting 3
Temp. setting 3 flashes, this will be the temperature that is set for the third time period, this should be the temperature that you want the house to be at during the afternoon/ evening when the house is occupied
Repeat the process to set to set the required temperature for Temp. setting 3
Time setting 4 hours flash, this will be the time that the temperature is set to another value, maybe lower for the night time period
Repeat the process to set the hours and minutes for Time setting 4
Temp. setting 4 flashes, this will be the temperature that is set for the fourth time period, this should be the temperature that you want the house to cool down to during the night
Repeat the process to set to set the required temperature for Temp. setting 4
If you require time and temperature settings, repeat the whole process for the Time settings 5, 6 and Temp. setting 5

If after setting the time periods 5 and 6 you decide that you no longer require it and wish to disable it, follow these steps:

In the Time program, cycle through time periods by just pressing the knob to accept the time and temperature setting until you reach time setting 5
Turn the knob to set the flashing hours to 00
Press to accept and the minutes flash
Turn the knob clockwise to 00 and then the display changes to just dashes and time period 5 is disabled
Repeat this process for temperature setting 5 and time setting 6

HW (Hot water)
The top line of the display shows the words Time programs plus flashing arrow heads at each end, this indicates that there are more programs:

Time programs

This Time program is used to set your required ON and OFF times for the hot water. The Programmer has default time settings as shown below:

06:30		08:30	16:30	22:30
DHW	ON	OFF	ON	OFF

Time programs
Select DHW programs with the knob, and press to enter. In the DHW program you can select ON and OFF times for the hot water heating, there are three ON and three OFF programs. Using the knob you can select various combinations of days or individual days:

Mon to Fri
Sat and Sun
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday

Whether you choose to set the same times for Monday to Friday and different times for Saturday and Sunday or set times forindividual days the setting operation is the same.

Select the desired day(s) using the knob
Press the knob to select the first DHW ON setting
The hours flash
Turn the knob to select the desired hours setting
Press the knob to confirm
The minutes flash
Turn the knob to select the desired minutes
Press the knob to confirm
The first DHW OFF hours flash
Turn the knob to select the desired hours setting
Press the knob to confirm
The minutes flash
Turn the knob to select the desired minutes
Press the knob to confirm
Now the second DHW ON hours flash
Repeat the process to set the hours and minutes for the seconding DHW ON times
Repeat the process for the second DHW OFF times

Information

If the third DHW period is not required repeatedly press the knob to cycle through the third period without making any settings

Repeat the whole process for the third DHW ON and OFF times, if required
If after setting the third DHW time period you decide that you no longer require it and wish to disable it, follow these steps:
In the Time program, cycle through DHW time periods 1 and 2 by just pressing the knob to accept the time setting until you reach period 3
Turn the knob to set the flashing hours to 00
Press to accept and the minutes flash
Turn the knob clockwise to 00 and then the display changes to just dashes and period 3 is disabled

Holiday function

Turn the knob to select the Holiday function
Press the knob to enter the program and OFF is displayed
Press the knob and OFF flashes
If ON is selected and the knob pressed, two day/months selections are displayed and the first day of the holiday period flashes
Turn the knob to select the desired day
Press the knob to confirm the month now flashes
Turn the knob to select the desired month
Press the knob to confirm
Now the last day of the holiday period flashes
Turn the knob to select the desired day
Press the knob to confirm and the month now flashes
Turn the knob to select the desired month
Press the knob to confirm
Holiday will be displayed when the function is active
Press the Return button to leave the program after setting.

When the Holiday function is set, via this program, the function will become active at midnight of the day set and inactive at midnight on the last day set. During the holiday period the hot water and CH functions are off and will return to normal operation at the end of the holiday period. The Frost symbol is displayed, indicating that the boiler is OFF but is protected when the temperature falls below 5 °C.

To cancel the holiday function:

Press the menu key for more than three seconds to enter user menus and select Holiday, ON will be displayed.
Press the knob and ON flashes, turn the knob to select OFF
Press the knob to confirm OFF
Press the return button to go back to the normal display

Info
Turn the knob to select Info and press the knob, two menus are available:

DHW
Signal strength

DHW

Turn the knob to select DHW and press to enter. The current temperature of the DHW is displayed:
- Actual temp
Press the Return button to go back to DHW

Signal strength
Turn the knob to select Signal strength and press the knob to enter the function. The signal strength is displayed as a number from 0 to 10 in the area where the temperature is normally displayed

0	=	no signal
1 – 3	=	weak signal
4 – 6	=	acceptable signal
7 – 10	=	very good signal

Setting

Turn the knob to select Settings and press to enter the function. Three sub programs are displayed:
- Language
- Time/date
- Format
- Reset all

Language
This function allows you to choose the language used by the Programmer, by default is set to English (EN).

Turn the knob to select language, EN flashes, select either:
- EN (English)
- NL (Dutch)
- dE (German)
Press the knob to confirm the desired language

Time/Date
This function allows the current time and date to be set, this would be used on initial set up of the Programmer or if the time and date were lost due to the boiler being switched off for an extended period of time. Turn the knob to select Time/date and press to enter the function:

Press the knob to select clock time
Press the knob and the hours flash
Turn the knob to select the correct hour
Press the knob to confirm the selection and minutes flash
Turn the knob to select the correct minutes
Press the knob to confirm the selection
Turn the knob to display the date set up
Press the knob to select the function, the day flashes
Turn the knob to select the correct day
Press the knob to confirm the correct day and the month flashes
Turn the knob to select the correct month
Press the knob to confirm and the year flashes
Turn the knob to select the correct year
Press the knob to confirm to set the year
Turn the knob to display the DST (Daylight savings time)
Press the knob and ON flashes
Turn the knob to select ON or OFF
Press the knob to confirm the selection
Press the return button to go back to Time/date and turn the knob to select Format

Format
Press the knob to enter the format function and the following sub menus are available:

Date format
Time format
Sensor calib.
Contrast

Date format
This function allows you to change the way the date is displayed, by default the format is DD.MM.YYYY. Once the date and time have been set the date format can be set:

Turn the knob to select the Date format function
Press the knob to show the date format flashing
Turn the knob to select either:
DD.MM.YYYY
MM/DD/YYYY
When the desired format for the date has been selected, press the knob to confirm and wait a few seconds for the display to return to the Date format

Time format

Turn the knob to select Time format
Press the knob and the time format is displayed flashing
Turn the knob to select either:
- 12 hour
- 24 hour
Press the knob to confirm once the choice has been made
When the desired format has been selected, turn the knob to display Sensor calib.

Sensor caliber.

If it is suspected that the temperature display is off by a few degrees and if there is a precision temperature gauge/meter available, the display can be offset by ± 5 °C to compensate.

The default value is 0.0 °C.

Press the knob to enter the temperature offset function, and the offset value is displayed, by default, it is 0.0 °C.
Press the knob and the display flashes.
Turn the knob to adjust the temperature offset, between -3 and +3 °C.
Press the knob to confirm the desired setting
When the desired format has been selected, turn the knob to display the Contrast

Contrast

Press the knob to select Contrast, this function allows you to adjust the contrast of the screen, by default it is set to 10
Press the knob to select Contrast
The current contrast flashes
Turn the knob to select from 0 to 20 the desired level of contrast
Press the knob to confirm
Press the return button at any time to return to the next higher level, you can keep pressing the return button until you return to the normal display.

Reset all

Turn the knob to select Reset all, this function will reset all the Programmable Room thermostat user settings back to the factory default settings.
Any customised ON /OFF times and temperatures for heating or ON/OFF times for hot water or any other customised settings will have to be re-entered.
Any default settings are described at the beginning of the functional descriptions.
Turn the knob to select Reset all
Press the knob and NO flashes
If a reset is required turn the knob to select YES
Press the knob to confirm

Dashes progress across the screen until four are displayed briefly, then the display reverts to just showing Reset all The Programmable room thermostat will be reset to factory default settings, as shown in the table below, any customised times for heating or hot water will have to be re-entered.

06:30		08:30	16:30	22:30
CH	1st	2nd	3rd	4th
CH TEMP	20 °C	16 °C	21 °C	10 °C
DHW	ON	OFF	ON	OFF

Installer

These functions are only used by the installer/service engineer and are useful during both installation of the Comfort II RF to make adjustment to suit the heating system; during an annual service/inspection, or to assist with fault finding. Press the menu button and return button for more than three seconds to enter the Installer setting area of the programmer.Six icons are shown across the top of the display:

Heating (CH)
Hot Water (HW)
Holiday
Info
Settings
Installer setting

Selections 1 to 5 are the same as the Timer / programmer user menu, section 5.1. Turn the knob to select the Installer icon and press the knob to enter the function.

Installer settings menu options

System data
Reset all
Heat circuit
Maintenance
System info
Radio settings

The menu options are displayed on the top line with flashing left and right arrows heads, indicating that there are other menu options available. Turning the knob will select each option in turn, eventually returning to the first option.

System data

Turn the knob to select System data
Press the knob to enter System data and HC assignment is displayed
The display shows the number 1 or 2 for the second heat zone
This indicates which heating zone the controller is assigned to
Press the Return button to go back to System data

Reset all
The Programmer Installer menus will be reset to factory default settings, any default settings are described at the beginning of the functional descriptions.

Turn the knob to select Reset all
Press the knob and NO flashes
Turn the knob to select NO or YES
Press the knob to confirm, if YES is chosen all menus within the Installer menu are reset back to default settings, four dashes progress across the display until the reset has taken place,
if NO is chosen, no reset takes place

Heat circuit
This function allows the Installer/Service engineer to set the maximum flow temperature for the central heating circuit to potentially increase the efficiency of the heating system, the default value is 85 °C.

Turn the knob to select Heat circuit
Press the knob to display Max flow in °C
Press the knob and the temperature flashes
Turn the knob to set the desired temperature for your system design requirements
Press the knob to confirm
Press the Return button to go back to Heat circuit

Maintenance

Fault history
- Boiler faults
- Cont. faults
Landlord func.
- Maint. date
- Maint. contact

Fault history

Press the knob and Boiler. faults is displayed. Boiler faults are displayed here and at the boiler, the Programmable Room thermostat may be located remotely from the boiler, so viewing the boiler faults at the Programmable Room thermostat may be useful
Press the knob and the first of five faults is displayed with the fault code and occurrence date. The fault screens can be scrolled through using the knob. If no faults have occurred, the text No fault will be displayed
Press the Return button to go back to Boiler faults
Turn the knob and Cont. faults is displayed
Press the knob and the first of five faults is displayed with the fault code and occurrence date. The fault screens can be scrolled through using the knob. If no faults have occurred, the text No fault will be displayed.
Press the Return button to go back to Cont. faults
Or press the Return button again to go back to Fault

History
Turn the knob to select Landlord func. or press the Return button go back to Maintenance

Call the Worcester Bosch technical support team for instructions of how to set the Maintenance message or contact telephone number

This function is for social housing landlords only and enables a maintenance/annual service date to be set. The maintenance reminder message “Maintenance” is displayed 30 days before the set date. Along with the Maintenance message a contact telephone number will also be displayed. The tenant should call this number to arrange a convenient date with the landlord for the service. If the maintenance reminder message is not cleared or reset to a later date, by the service engineer, then 14 days after the scheduled maintenance date the controller will limit the room temperature set point to 18°C.

System info

Turn the knob to select System info
Press the knob and Install date is displayed
Press the knob and the install date is displayed
Press the knob to return to Install date
Turn the knob to select SW controller
Press the knob to display the software controller version
Press the knob to return to SW controller
Press the return button to go back to System info

Radio settings – Pair/Unpair

Key lock
When the Key lock is active, no user interaction with the units is possible, if a button is pressed or the knob turned/pressed the word Key lock is displayed.

Key lock ON

To activate the Keylock:
Hold down the CH Select button and the knob at the same time for more than three seconds and the Keylock is active

Key lock OFF

To de-activate the Key lock:
Hold down the CH Select button and knob at the same time for more than 3 seconds and the Key lock is de-activated

Receiver
The Receiver is paired with the Programmable room thermostat and they communicate via an RF signal. The Receiver unit has an Override/Pairing push button and a LED to indicate various sates of operation.

Override push button

If the RF signal between the Receiver and the Programmable room thermostat is lost the LED, on the Receiver, will flash once a second, indicating a local error (not a boiler fault).
During this time, the override push button can be briefly pressed once (less than 3 seconds) to override the
Programmable room thermostat and maintain the boiler function for heating and hot water.
During override the LED will be on but will flash off briefly to indicate an override situation.
Press the override push button again briefly, to cancel the override feature.

Pairing/Unpairing

LED (for flash codes refer to the table below)
Override button/Pairing button

Green indicator LED		Indicates the status:
Normal operation	OFF	No central heating zone is calling for heat
Normal operation	ON	One or more zones calling for heat
Manual override	Flashing off, for ¼ second over a 2 second period	Manual override is active
Pairing modes	2 x ¼ second flashes over 5 a sec. period	Pairing in operation
Pairing modes	5 x ¼ second flashes over 5 a sec. period	Unpairing in operation
Push button	Press for >5 seconds for pairing Press for >10 sec. for unpairing	Pairing or unpairing the Receiver with the Programmable room thermostat(s)
Push button	Press once, briefly, for override, press again for no override	Manually switching the boiler ON or OFF

Fault finding and resolution

If a fault code is displayed the user must first press the knob to return to the main display.
The last 5 control faults can be viewed in the Faults history (refer to 5.2.4 Maintenance).
If a fault appears that is not listed within the table it could be that a boiler fault has occurred.
The boilers Installation & servicing manual should then be consulted

Fault table

Fault code Problem Description Resolution
	The temperature displayed on the thermostat unit is different than the room temperature	The temperature offset setting is other than 0	Check the temperature offset setting on the Programmable thermostat (Setting menu à Format à Sensor calib. refer to section 5.1.5) and adjust as required.
		Room-to-room temperature difference	Consider differences between rooms due to draughts, sunshine, etc. Move the Room thermostat to a more suitable location if necessary.
	The required room temperature has not been achieved	Airlock	Bleed the radiators and vent the heating system.
		Low system pressure	Top up the system pressure via the filling link.
		Time program/weather change	Is the heating on for long enough?
		Flow temperature	Set a higher flow temperature.
		Thermostat valve in the reference room	Operate the TRV to ensure that it does not stick
		Thermostat valve in the reference room	Fully open the TRV.
	The room temperature is higher than the set value	The Room thermostat is subject to draught or energy loss	Move the Room thermostat to a more suitable location (refer to section 3.2).
	No flame symbol visible on the Room thermostat	The actual temperature is close to the target temperature. The control turns the boiler off early to prevent overshoot.	Set the target temperature is at least 2 ºC above the currently displayed temperature. It takes up to 6 minutes for the flame to come on.
	The flame symbol is not available with oil-fired boiler controls.
	Cannot select DHW mode on the Room thermostat. NA is displayed.	The Room thermostat is part of a multiple heating zone system in combination with the Greenstar Wiring Centre. Only the primary Room thermostat (the first to be paired with the Receiver) is controlling the DHW mode.	Select the required DHW mode on the primary Room thermostat.
A21/ A22	Loss of RF signal	The Room thermostat unit is incorrectly positioned	Check signal strength and reposition Room thermostat for better signal. Wire the Receiver to a wall plate if the boiler is in a loft or garage.
		The receiver or Room thermostat unit has no power supply	Check that boiler has power and that the Room thermostat batteries are not running low (see Blank display or low battery symbol).
		A21 will be displayed at the initial switch-on until the two units have established an RF communication link	Allow up to 1 minute after power up for the units to communicate.
A23	Room stat internal sensor failure	Internal room temperature sensor out of valid range	Replace the RF Room thermostat.
A24	The remote RF unit has a fault	Another room thermostat in the system has a problem	Check other room thermostats within the system for fault codes.

Fault code Problem Description Resolution
A25	Multiple pairing fault	Displayed when no zone is available for this room thermostat	Unpair units and pair back up using a different zone setting for each room thermostat. Up to 3 zones can be set up.
A26	Multiple pairing fault	Displayed when 2 or more Programmable room thermostats are paired to the same Receiver, each with the same zone setting.	Unpair all units and pair back up using a different zone setting for each room thermostat.
A27	Unable to communicate with boiler’s EMS bus	Boiler is EMS compatible but no communication	Replace the Programmer/Receiver unit.
A28	Not paired	Unit is not paired	Unpair and pair all (see section 7.2).
	Receiver LED flashing once per second (1 Hz)	Not a boiler fault, possibly no RF connection with the Programmable room thermostat(s), at least one connection has been lost	Check the Programmable Room thermostat(s) for fault code (if none is displayed, turn the knob).
	Blank display or low battery symbol	Batteries are depleted	Replace batteries and clean battery contacts.
Other fault		Comfort II Room thermostat also displays boiler fault codes.	Refer to the boiler’s Installation, Commissioning and Servicing instruction manual.

Unpair

Set the Receiver to the unpairing mode:

Press and hold override/pairing button until the LED flashes 5 times in a 5 second period, press for approximately 10 seconds. Not to be confused with the flashing frequency of the pair mode
Set the Room Thermostat in unpairing mode
Turn the knob to select the Installer icon and press the knob to enter the function
Select Radio settings and press the knob
Select Pairing and press the knob
Select Unpairing and press the knob
Wait until the action is completed
When the unpairing between the devices is completed, A28 appears on the Room thermostat display and the Receiver’s LED flashes once per second. The action takes approximately one minute.

Pair

Set the Receiver to the pairing mode:

Press and hold override/pairing button until the LED flashes twice in a 5 second period, press for more than 5 seconds but less than 10 seconds.

Set the Room Thermostat in pairing mode

Turn the knob to select the Installer icon and press the knob to enter the function
Select Radio settings and press the knob
Select Pairing and press the knob
Select Pairing and press the knob

Wait until the action is completed
When the pairing between the devices is completed, HC Assignment 1 appears on the Room thermostat display. The Receiver’s LED stops flashing, pairing is now complete. Wait or press the knob to return to the main screen. The action takes approximately one minute.

Servicing

These units can not be serviced.
Should either unit fail to function correctly check that the:
Programmable room thermostat settings are correct
RF signal link between the units is set up correctly, sections 6.2 and page 15 Radio settings
Programmable room thermostat batteries are the correct type, fitted correctly, and are not exhausted. If in doubt, fit new batteries section 9.

Maintenance
These units require no maintenance apart from replacing used batteries in the programmable room thermostat. The outer casing can be wiped clean using a dry cloth, do not used polish or detergents.

Programmable room thermostat battery replacement
If under normal operation the battery low symbol appears, the batteries require replacing within 60 days or the programmed settings will be lost. Replace the batteries with the same type: LR6/AA 1.5V alkaline.

Battery access
To remove the room thermostat from the wall mounting plate:

Insert a suitable flat bladed screwdriver into the slot on the bottom edge of the device
Twist the screwdriver gently until the bottom catches are released.
Separate the Programmable room thermostat from the its wall plate.

Battery replacement

Replace the spent batteries with new ones of the same type (AA), ensuring that they are installed in the correct orientation. Insert the batteries ensuring that the positive + end of the battery is inserted into the positive + terminal of the holder. Fit the Programmable room thermostat to the wall plate, locating the catches [1] on the top edge and then snap the bottom edge into place.

ErP Class

The data represented in the table below is required for the completion of Energy Related Product (ErP) Directive System Package fiche and, subsequently, the ErP system data label. ERP Labelling obligation applicable from 26th September 2015.

Supplier	Worcester Bosch Group
Model	Comfort II
ErP Class	V
Function and ERP description	Load compensation Modulating room thermostat, for use with modulating heaters: An electronic room thermostat that varies the flow temperature of the water leaving the heater dependant upon measured room temperature deviation from room thermostat set point. Control is achieved by modulating the output of the heater.
Additional seasonal space heating efficiency gain	+3%

Environment / disposal
Environmental protection is a fundamental corporate strategy of the Bosch Group. The quality of our products, their economy and environmental safety are all of equal importance to us and all environmental protection legislation and regulations are strictly observed. We use the best possible technology and materials for protecting the environment taking account of economic considerations.

Packaging
We participate in the recycling programmes of the countries in which our products are sold to ensure optimum recycling. All of our packaging materials are environmentally compatible and can be recycled.

Electrical and electronic equipment
Scrap electrical and electronic equipment must be collected separately and returned to an environmentally compatible recycling facility (EuropeanDirective on waste electrical and electronic equipment). Use the country specific return and collection system for the disposal of electrical and electronic equipment.

Battery recycling
Batteries, rechargeable or not, must not be disposed of into ordinary household waste. Instead, they must be recycled properly to protect the environment and cut down on the wasteof precious resources. Your local waste management authority can supply details concerning the proper disposal of batteries.

Worcester

Worcester, Bosch Group
Cotswold Way, Warndon, Worcester WR4 9SW.
Tel. 0330 123 9559
Worcester, Bosch Group is a brand name of Bosch Thermotechnology Ltd.

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WORCESTER Comfort II RF Programmable Room Thermostat Installation and operating instructions

Tagged Comfort II RF Thermostat, Comfort+ II RF, Installation and Operating Instructions, Programmable Room Thermostat, Worcester, WORCESTER Comfort II RF

WORCESTER Comfort II RF Programmable Room Thermostat Installation and operating instructions