Bosch Worcester Greenstar CDi Compact ErP Series - Existing Installations

INSTALLATION
CDi Compact
ErP
- 6 720 813 276 (2015/07) 33
5.7.3 Existing installations
For boiler replacements on an existing system, it is not necessary to zone
the upstairs and downstairs separately, compliance with the zone
requirements can be achieved by a single room thermostat or
programmable room thermostat.
While the system is drained down, TRVs must be fitted to all rooms
except the bathrooms and the room with the room thermostat.
The following figures show the options of room thermostat with
programmer, room thermostat only or programmable room thermostat.
EXTERNAL 230V PROGRAMMER AND ROOM THERMOSTAT
Fig. 50 Room thermostat with programmer
[1] Series connector, not supplied. Connector to be made safe.
ROOM THERMOSTAT ONLY
Fig. 51 Room thermostat with plug in timer
PROGRAMMABLE THERMOSTAT
Fig. 52 Programmable thermostat
▶ Remove the link between L
R
(CH) and L at the 230V OUT terminal
block connection.
▶ Connect external controls LIVE supply to terminal L at the 230V OUT
terminal block connection.
▶ Connect external controls LIVE return to terminal L
R
(CH)
▶ Connect external controls NEUTRAL to terminal N at the 230V OUT
terminal block connection.
OPTIONAL EXTERNAL FROST STAT CONNECTION FOR PROTECTION
OF SYSTEM PIPEWORK IN UNHEATED AIR SPACE
▶ Connect frost thermostat cables to terminals F
S
& F
R
.
▶ These connections are not polarity sensitive.
▶ The external frost thermostat only operates the pump.
Fig. 53 Frost Thermostat
Pre-wired CH & DHW links
▶ Remove link when connecting external CH control
▶ Remove link when connecting external DHW control
1
CH ON
PreHeat
230V
MAINS
SUPPLY
N
E
L
230V
IN
230V
OUT
FR FS
LR
LR
LN
L
N
LN
LN
LN
6720646608-33.2Wo
Room Thermostat
Programmer
Room Thermostat
230V
MAINS
SUPPLY
Plug in
Worcester timer.
(see timer operating
instructions for
installation)
NEL
230V
IN
230V
OUT
FR FS
LR
LR
LN
L
N
LN
LN
LN
6720646608-34.2Wo
The programmable room thermostat may be a hard
wired or RF type.
This diagram is applicable for a hard wired unit or the
receiver section of the RF pack.
1 The link between the Live (L) and Common (C) may already be
fitted as part of the Programmable thermostat, if not then a link
must be wired in.
Live Return (L
R
) is sometimes referred to as
‘Call for Heat’ or ‘Switched Live’.
Some devices do not require connection of a neutral i.e.
battery powered devices.
Programmable
Thermostat
NL
C CALL
230V
MAINS
SUPPLY
NEL
230V
IN
230V
OUT
FR FS
LR
LR
LN
L
N
LN
LN
LN
6720646608-35.2Wo
1
Wiring to Part L
zoned controls
Frost Thermostat
230V
MAINS
SUPPLY
N
E
L
230V
IN
230V
OUT
FR FS
LR
LR
LN
L
N
LN
LN
LN
6720646608-38.2Wo
Pipe Thermostat