Buderus 500 - 24/C User manual

Please read thoroughly before operating the unit
7215 3500 - 02/2005 GB(EN) For the user
Users manual
Wall-mounted condensing gas combi
boiler Buderus 500 - 24/C, 500 - 28/C

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Introduction
Please read these instruc-
tions and follow them care-
fully for a safe and
economical use of your
combi boiler.
Important general
instructions for use
This device should only be
used for its intended purpose
and in accordance with the
regulations.
It is a requirement and in
your own interest, and that of
safety that this boiler must be
installed by a CORGI regis-
tered installer, in accordance
with the relevant require-
ments of the current Gas
Safety (Installation and Use)
Regulations,

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The Building Regulations, current I.E.E. Wiring Regulations
and the relevant British Standard Codes of Practise.
The device may only be used in combination with the units,
accessories and spare parts listed in the installation and
maintenance instructions.
Other combinations of units, accessories and consumables
are only to be used if they completely fulfil the specifications
involved, and if system performance and safety are not
affected in any way.
Subject to technical modifications
As a result of our policy of constant development, there may
be small differences with respect to illustrations, functional
steps and technical data.
Cleaning
For normal cleaning simply dust with a dry cloth. To remove
stubborn marks and stains, wipe with a damp cloth and soap
and finish off with a dry cloth.
DO NOT use abrasive cleaning materials.
G. C. Aplliance No. :
Buderus 500-24/C : 41-110-04
Buderus 500-28/C : 41-110-03

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Contents
1 Safety precautions . . . . . . . . . . . . . . . . . . . 6
2 Installation area / boiler room . . . . . . . . . . 7
3 Working in the heating system . . . . . . . . . 8
4 Functions of the system and operating
instructions. . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Conversion to LPG. . . . . . . . . . . . . . . . . . . 9
7 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . 9
8 Permanent clearances . . . . . . . . . . . . . . . 10
9 DBA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
10 Initial start-up . . . . . . . . . . . . . . . . . . . . . . 16
10.1 Preparing for operation. . . . . . . . . . . . . . . . . . . . . 16
10.1.1 Check water pressure . . . . . . . . . . . . . . . . . . . . . 16
10.1.2 Topping up the heating system . . . . . . . . . . . . . . 17
10.1.3 Temperature-setting adjustments. . . . . . . . . . . . . 20
10.2 Operational and fault codes . . . . . . . . . . . . . . . . . 23
11 Taking the system out of service . . . . . . 24
11.1 Draining the system in case of frost . . . . . . . . . . . 25

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Preface
Dear Customer,
Your Buderus 500 Series wall-mounted condensing gas
combi boiler has been designed and built in accordance with
state-of-the-art technological standards and the recognised
safety rules. Special focus has been placed on operator
convenience in this respect.
Carefully read the safety instructions and operating manual to
ensure safe, economic and ecologically beneficial use of the
unit.
Due to the high efficiency of the boiler a plume of water vapour
may form at the terminal during operation. This is normal.

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Safety precautions
1 Safety precautions
ADANGER! If you smell gas:
1) No naked flames ! Do not smoke !
2) Avoid sparks ! Do not operate electrical swit-
ches. Do not use the telephone, plug-in devices
of any kind or the doorbell!
3) Shut off the main gas supply!
4) Open windows and doors!
5) Warn building occupants and evacuate the
building!
6) Call the gas distributor (under 'GAS' in the
telephone directory) from outside the building!
INOTE
In the event of any other type of incident, shut off the
main gas supply and electric supply to the appliance
and seek assistance from a CORGI registered
engineer.

Installation area / boiler room
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2
2 Installation area / boiler room
ADANGER!
The air intake and outlet openings must not be reduced
in size or closed.
ADANGER!
Do not store or use inflammable materials or liquids
near the heating boiler.
INOTE
To prevent the boiler from being damaged, care must
be taken not to contaminate the combustion air with
halogenated hydrocarbons (e. g. contained in aerosol
sprays, solvents, detergents, paints, and adhesives), or
with high quantities of dust. The room in which the
boiler is installed must be frost-proof and be well
ventilated.

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Working in the heating system
3 Working in the heating system
ADANGER!
Only a CORGI registered Engineer is to be entrusted
with the installation of this boiler, the gas supply and the
flue connection. Commissioning, Servicing and any
Repairs must be carried out by a competent person i.e.:
a CORGI Registered Engineer.
All CORGI Registered Installers carry a CORGI
identification card and have a registration number.
Both should be recorded in your boiler logbook.
You can check if your installer/Engineer is registered by
telephoning 01256 372300 or by writing to:
CORGI, 1 Elmwood, Chineham Business Park,
Crockford Lane, Basingstoke. RG24 8WG.
INOTE
It is mandatory to clean and service the system once a
year ! This includes an inspection of the entire system
to see if it is in full working order. Any faults and defects
found in the course of inspection must be rectified
immediately.
It is recommended to enter into a service contract with a
specialist company.

Functions of the system and operating instructions
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4 Functions of the system and operating
instructions
The installer should familiarize the user with the functions and
operation of the heating system and ensure that a complete
set of technical documentation is supplied.
5 Maintenance
The appliance should be serviced at least once a year by a
CORGI registered installer.
6 Conversion to LPG
The boiler is suited for natural gas. To convert the boiler to
LPG you must contact a CORGI registered fitter.
7 Abbreviations
DBA = Control unit (Dedicated Burner Automat)
MCW inlet = Mains Cold Water inlet
DHW outlet= Domestic Hot Water warm outlet
CH flow = Central Heating flow
CH return = Central Heating return.

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Permanent clearances
8 Permanent clearances
The boiler must be located in an area with the following
permanent clearances.
fig. 1
21 mm
21 mm
8 mm 8 mm 8 mm

Permanent clearances
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8
INOTE
The permanent clearances do not change if a wall
spacing frame is used.
The installer or service engineer must be able to create
sufficient service clearences. These clearences should
have been considered at time of installation.

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DBA
9DBA
fig. 2 DBA
1
2
3
45
6
7

DBA
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9
Key to fig. 2 :
The boiler is equipped with a DBA. This is the internal control
of the boiler. The DBA is located behind the access panel.
The DBA allows you to operate the boiler and to make adjust-
ments in its settings.
DBA overview:
1. Mains switch (see fig. 2).
Use this switch to turn the boiler on or off.
2. Reset button "B" (see fig. 2)
When a blinking code is in the display, it is possible to try and
restart the boiler by pressing this button.
INOTE
It is not possible to reset the boiler when there is no
fault code blinking in the display.
item 1: mains switch
item 2: "reset" button
item 3: "service" button
item 4: display
item 5: "menu" button
item 6: adjusting arrow up
item 7: adjusting arrow down

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DBA
3. Service Button "A" (see fig. 2)
Is used for servicing purposes only.
DO NOT use this button!
4. Display (see fig. 2)
The display visualizes settings, adjustments and fault codes
(see fig. 3).
fig. 3 DBA display

DBA
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5. Menu button "E" (see fig. 2)
The menu button "E" allows you to scroll through the menu
items.
Pressing the Ebutton once, the current warm start function
setting is displayed.
Pressing the Ebutton again gives the current DHW tempe-
rature setting is displayed.
Pressing the Ebutton again gives the current setting of
summer operation.
Pressing the Ebutton once more gives the current CH flow
temperature setting.
6. and 7. Up "C"and Down "D"keys (see fig. 2)
These keys can be used for adjusting temperatures and
activating or de-activating certain summer operation.
The Ckey when pressed gives the current operating status
of the boiler.

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Initial start-up
10 Initial start-up
10.1 Preparing for operation
Please also note the user manual supplied with the
external time controls and thermostat.
10.1.1 Check water pressure
zCheck the pressure gauge (fig. 4, item 3) located at the
bottom of the boiler for the current system pressure.
Optimum system pressure is 1.5 bar.
fig. 4 Servicing valves
DHW
outlet GasCH
flow
CH
return
MCW
inlet
12
3
3

Initial start-up
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10
10.1.2 Topping up the heating system
AWARNING!
The wall-mounted condensing gas combi boiler must
not be activated at this stage.
The system should be filled with untreated mains water.
zTurn off the boiler by setting the mains switch to "0" (fig. 5,
item 1).
zIf necessary open the CH flow and CH return servicing
valves (fig. 4, item 1 and 2).
fig. 5 DBA – Mains switch
ON
OFF
1

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Initial start-up
zConnect filling loop (accessory) (fig. 6).
zOpen both stop valves (fig. 6).
zFill the system to a pressure of approx. 1.5 bar
(fig. 4, item 3).
zShut both stop valves.
zDisconnect the filling loop.
zVent all radiators from air starting with the lowest radiator
and working your way up to the highest point.
fig. 6 Filling loop
filling
loop
stop
valve
stop
valve
double
check
valve
MCW
inlet
CH
return

Initial start-up
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10
zCheck the pressure after venting. If the pressure has
dropped under 1.0 bar then top up the system as described
previously.
zDisconnect the filling loop and cap off.
INOTE
If there are frequent water losses, have the system
examined and repaired by a CORGI registered
installer. Have the inhibitor concentration checked
every year.

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Initial start-up
10.1.3 Temperature-setting adjustments
Setting the warm start function
zPress Ebutton once.
zUse the Cand Dkeys to turn the warm start function on
or off (table 1). Factory setting: warm start function is "on".
Setting the domestic hot water (DHW) temperature
zPress Ebutton (see fig. 7, item 2) twice then adjust the
DHW temperature to the desired temperature (40 °C -
60 °C) using the Cand Dkeys (fig. 7, item 1).
Factory setting is 48 °C.
Setting Meaning
H- ECO / cold start More energy efficient, less chance of
calcification, longer waiting periods.
I- comfort / warm start
Maximum comfort due to short wait-
ing period for warm water. Not as
energy efficient as the cold start and
there is more chance of calcification.
table 1 Warm start function