Technical data

54
The CDi regular and system series
design benefits in operation
Whenever a demand for DHW or CH is made, the boiler’s electronic
control system is energised and the burner electronically ignites via
a flame ionisation system.
The pre-mix burner automatically adjusts to the set level. The flow
temperature of the boiler is then maintained at the customer setting
by the facia mounted variable control. Should the system
requirements reduce during operation (TRVs closing down, etc.) and
the flow temperature exceed the customer setting then the burner
will modulate downwards to match the system demand level. Should
the flow temperature continue to rise then the burner will be
de-energised and the control system will go into an anti-cycle mode
and not allow the appliance to re-fire for a set period.
The Greenstar CDi regular and system
condensing boiler series
DT10RF optimiser
A seven day digital programmable RF
thermostat with a seven day programmer/
receiver in the boiler fascia. The transmitter
is the tried and tested optimiser as available
with other Worcester boilers. The optimum
start feature, where the thermostat delays
the firing of the boiler until necessary, is a
useful energy-saving option.
Intelligent System Package (30CDi System only)
An optional package for Greenstar CDi
system boilers. The combination of the
TD200 text display and RT10 room
thermostat with a built-in diverter valve motor
provides an intelligent control upgrade with
easy-to-use features.
TD200 text display*
A seven day programmer with easy-to-use
text display with automatic time and date
setup, automatic summer/winter time
changeover and a backlight for use in low
light conditions. Three on/off periods can be
set per day. The TD200 can be fascia
mounted or hard wired outside the boiler using the optional wall
mounting socket. The TD200 features an easy-to-use full text
display providing more information than standard digital controls.
A hard wired room thermostat is available to provide optimum start
functionality.
RT10 room thermostat*
A hard wired optimising room temperature
controller with digital display for use with the
TD200. The display shows current and
desired temperature and an advance button
allows the user to move to the next heating
switch point on the TD200.
Wall mounting socket
A Worcester branded wall mounting socket
which allows the TD200 to be hard wired
away from the boiler.
Increased SAP ratings
As well as the CDi models achieving very high SAP ratings for
dwellings, the addition of the optimising temperature controller
further increases these ratings as well as being part of the
recommended best practice, as covered by the CHESS design
standard.
The Worcester Greenstar CDi Conventional is a wall-mounted,
gas-fired condensing ‘heating only’ or regular boiler. The appliance
combines, within one casing, a cast-aluminium heat exchanger, fan,
gas valve and other electronic and mechanical equipment
necessary to provide central heating.
It is particularly suited to an older system which may not sustain
the higher pressures a system boiler or combi operates under.
With a feed and expansion cistern in the roof space, any ‘topping
up’ of the system is automatic, unlike a sealed system which
requires manual filling.
The Greenstar 30CDi System boiler is a compact and highly
efficient unit giving all the heating and hot water required, with
significant savings on running and installation costs. The Greenstar
30CDi System boiler incorporates all the major components
built-in, including an expansion vessel and modulating pump. All
components are pre-wired, pre-plumbed and pre-tested for greater
reliability as well as quicker and neater installation.
A condensing boiler is more efficient due to its ability to extract
more heat from the flue gases normally lost to the environment
through the flue system.
All the Greenstar CDi models use the same Aluminium-Silicon
heat cell with an extra large surface area.
As the flue gases pass through the heat exchanger this extra
surface area cools the flue gases to around 55°C whereupon the
latent heat within, which would normally be lost to the atmosphere,
is instead released and applied to the system.
It is this ability to extract as much heat as possible from the gas it
burns that gives the Greenstar CDi series an exceptionally high level
of operating efficiency.
This higher efficiency is recognised within section L of the
Building Regulations, subsequently achieving a higher SAP or
NHER rating.
Optional plug-in controls for the
Greenstar 30CDi System boiler
When used with optional diverter valve kit
DT20RF digital RF thermostat with twin
channel programmer
A wall-mounted RF room thermostat with
digital display, combined with a twin channel
digital timer in the boiler fascia. The fascia
mounted programmer benefits from
automatic time and date setup, automatic
summer/winter time changeover and a
backlight for use in low light conditions.
DT20 twin channel digital programmer
A versatile, easy-to-learn, 7 day, digital
programmer offering up to 3 on/off settings
per day. The programmer has a host of
innovative features including automatic setup,
which sets the correct time and date at
power-up, automatic summer/winter time
changeover and a green backlight for use in
low light conditions.
DT10RF digistat
A familiar wall-mounted 24 hour
programmable RF digital thermostat
combined with a fascia mounted single
channel programmer to time the hot water
cylinder or combi preheat functions. The
programmer includes a built-in receiver for
the room thermostat and all of the
functionality of the DT20.
Versatility
Gas
The Greenstar CDi regular and system series are available for use
with both natural gas and LPG.
Controls
The Greenstar CDi Conventional series feature:

Power on/off switch.

Variable temperature control selector.

An integral facia with status display lights and a digital display
which also operates as a fault diagnosis display.

DHW control for use with Intelligent System Package*.
Options
Fluing
The Greenstar CDi series features 2 different sizes of
multi-directional RSF flue systems, 100mm or 125mm.
The flue can be run horizontally or vertically with additional 90 or
45 degree in-line bends allowing changes of route or direction,
providing an extremely flexible and versatile fluing system enabling
the appliance to be sited virtually anywhere.
More details are shown on page 11.
*30CDi System boiler only.
GREENSTAR CDi
CONVENTIONAL
LAYOUT
GREENSTAR CDi SYSTEM BOILER
WITH LOW PRESSURE
HOT WATER
CYLINDER
GREENSTAR CDi SYSTEM BOILER
WITH UNVENTED HOT
WATER CYLINDER
*Not available separately. Part of the Intelligent System Package.
BBT181 Gstr CDi Conv T&S IssB 4/5/06 11:21 Page 4