Page 1
Users manual
Wall-mounted
condensing gas boiler
Buderus 800 - 24/29/43/60 and
Buderus 800 - 24T25/29T25 H/V
7212 3900 (03/2010) GB
For the user
Please read thoroughly
before operating the unit
Page 2
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
2
Subject to technical modifications !
Constant development efforts may result in minor deviations in
illustrations, functional steps and technical data.
Updating the documentation
If you have suggestions for improvement or have found
discrepancies, please do not hesitate to contact us.
Contents
1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
1.1 Dimensions, connections and assembly . . . . . . . . .6
1.2 Boiler assembly - exploded view. . . . . . . . . . . . . . .8
1.3 Flue Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . .9
1.4 Items supplied with unit. . . . . . . . . . . . . . . . . . . . .11
1.5 Gas boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
1.6 Water circulation system. . . . . . . . . . . . . . . . . . . .12
1.7 Pipe connections. . . . . . . . . . . . . . . . . . . . . . . . . .12
1.8 Flue installation. . . . . . . . . . . . . . . . . . . . . . . . . . .15
1.9 Electrical connections . . . . . . . . . . . . . . . . . . . . . .18
2 Initial start-up . . . . . . . . . . . . . . . . . . . . . . . . . . .23
2.1 Preparing the boiler for operation . . . . . . . . . . . . .23
2.2 Start-up work. . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
3 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
3.1 Preparing the heating boiler for inspection . . . . . .34
3.2 Checking for internal leaks . . . . . . . . . . . . . . . . . .34
3.3 Visual inspection . . . . . . . . . . . . . . . . . . . . . . . . . .34
4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
4.1 Cleaning the heat exchanger, burner and syphon 35
5 Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
5.1 Operating codes . . . . . . . . . . . . . . . . . . . . . . . . . .39
5.2 Fault codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
5.3 Checking and replacing parts . . . . . . . . . . . . . . . .48
6 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
6.1 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . .63
6.2 Residual pump lift for wall-hung gas boilers . . . . .65
6.3 Short list of spare parts . . . . . . . . . . . . . . . . . . . . .66
7 Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
7.1 Start-up report. . . . . . . . . . . . . . . . . . . . . . . . . . . .67
7.2 Inspection and service reports . . . . . . . . . . . . . . .68
The boiler meets the basic requirements of the
appropriate standards and directives.
Conformity has been substantiated by the
proper documents which - together with the
declaration
of conformity - are filed with the manufacturer.
Page 3
Preface
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
3
Preface
These installation and servicing instructions apply to:
Buderus wall-mounted condensing gas boilers
800 – 24/29/43/60 and 800 – 24T25/29T25 H/V.
Model B23, B33, C13, C33, C43, C53 and C
73
800 – 24/29/43: Category GB II
2H3P
20 mbar; 37 mbar
(natural gas
H and LPG)
In this document LPG = 3P-G31-37 mbar
800 – 60: Category GB I
2H
20 mbar
(natural gas
H)
Power rating: 230 VAC, 50 Hz, IP4X
Fuse rating: 1.25 slow blow
G. C. Aplliance No. :
Buderus 800 – 24 41-110-19
Buderus 800 – 29 41-110-20
Buderus 800 – 24 T25/V
Buderus 800 – 29 T25/V
Buderus 800 – 24 T25/H
Buderus 800 – 29 T25/H
Buderus 800 – 43 41-110-14
Buderus 800 – 60 41-110-15
Important general instructions for use
Only use the boiler in accordance with its designated
use and the installation and servicing instructions.
Servicing and repair must be carried out by Gas Safe
registered installer. Only use the boiler in combinations
and with the accessories and spare parts indicated in
the installation and servicing instructions. Other
combinations, accessories and consumables may only
be used if they are expressly provided for the designated
use and if system performance and safety are not
affected in any way.
The boiler is suitable for connection to fully pumped,
sealed water systems ONLY
. Adequate arrangements
for completely draining the system by provision of
draining valves must be provided in the installation
pipework.
Pipework from the boiler is routed downwards as
standard, but may be routed upwards behind the boiler
using the distance frame (supplied in a seperate kit).
Subject to technical modifications.
As a result of our policy of constant development, there
may be small differences between illustrations,
functional steps and technical data.
BENCHMARK' Log Book
All Buderus gas fired boilers now include an installation,
commissioning and service record log book. The details
of the log book will be required in the event of any
warranty work being requested. Please complete the
appropriate sections on completion of the installation
and commissioning.
REMEMBER: Please hand the log book back to the
user.
Regulations and directives
It is law that all gas appliances are installed and serviced
by a Gas Safe registered installer in accordance with the
regulations. Failure to install appliances correctly could
lead to prosecution. It is in your own interest, and that of
safety, to ensure the law is complied with.
The installation of the boiler MUST be in accordance
with the latest I.E.E. (
BS7671) Wiring Regulations, local
building
regulations, water regulations, the building regulations
and the Building Standard (Scotland) and any relevant
requirements of the local authority.
Detailed recommendations are contained in the
following British Standard Codes of Practice:
BS. 5440:1 Flues (for gas appliances of rated input
not exceeding 70 kW).
BS. 5440:2 Ventilation (for gas appliances of rated
input not exceeding 70 kW).
BS. 5449 Forced circulation hot water systems.
BS. 5546 Installation of gas hot water supplies for
domestic purposes (2nd. family Gases).
BS. 6798 Installation of gas fired hot water boilers
of rated input not exceeding 60 kW.
BS. 6891 Low pressure installation pipes.
IGE/UP/1b Tightness testing and purging domestic
sized gas installations.
Health and & Safety Document No. 635.
The Electricity at Work Regulations, 1989.
The manufacturer's notes must not be taken, in any way,
as overriding statutory obligations.
The design and construction of the Buderus wallmounted condensing gas boilers 800 – 24/29/43/60 and
800 – 24T25 /29T25 conforms to the basic
specifications listed in the European directive governing
gas-fired appliances 90/396/EEC, and with respect to
EN 625, EN 483 and EN 677.
Page 4
Preface
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
4
Timber Framed Buildings
If the boiler is to be fitted in a timber framed building it
should be fitted in accordance with the Institute of Gas
Engineering document
IGE/UP/7:1998.
Bathroom Installations
This appliance is rated IP4X.
The boiler may be installed in any room or internal
space, although particular attention is drawn to the
requirements of the current IEE (
BS. 7671) Wiring
Regulations and, in Scotland, the electrical provisions of
the building regulations applicable in Scotland, with
respect to the installation of the boiler in a room or
internal space containing a bath or shower.
If the appliance is to be installed in a room containing a
bath or shower then, providing water jets are not going
to be used for cleaning purposes (as in communal
baths/showers), the appliance can be installed in Zone
3, as detailed in
BS. 7671.
Compartment Installations
A compartment used to enclose the boiler should be
designed and constructed especially for this purpose.
An existing cupboard or compartment may be used,
provided that it is modified for the purpose.
In both cases, details of essential features of cupboard/
compartment design, including airing cupboard
installation, are to conform to the following:
BS 6798 (No cupboard ventilation is required - see 'Air
Supply' for details).
It is not necessary to have a porpose-provided air vent
in the room or internal space in which the boiler is
installed. Neither is it necessary to ventilate a cupboard
or compartment in which the boiler is installed, due to
the low surface temperatures of the boiler casing during
operation; therefore the requirements of
BS 6798, Clause
12
, and BS 5440:2 may be disregarded.
The position selected for installation MUST allow
adequate space for servicing in front of the boiler.
For the minimum clearances required for safety and
subsequent service, see the wall mounting template.
In addition, sufficient space may be required to allow
lifting access to the wall mounting plate.
Wall-mounted condensing gas boilers must only be
operated with the combustion air/flue gas systems
especially devised and authorised for this type of boiler.
Observe the relevant standards, regulations and
legislation of the country of final use.
NOTE
Observe the corresponding technical rules
and the building supervisory and statutory
regulations when installing and operating
the system.
WARNING!
Keep the burner-control unit housing
CLOSED when working on water-bearing
components.
NOTE
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. Defects and faults
must be eliminated immediately.
NOTE
When instructions aren’t followed, warranty
expires.
CAUTION
Use this device for its intended purpose
only.
Page 5
Preface
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
5
DANGER!
Notes relating to the heating system water.
Thoroughly flush the system before it is
filled with water. Use only untreated water
or water treatment product such as Sentinal
X100 to fill and top up the system.
When using water treatment, only products
suitable for use with Buderus heat
exchangers are permitted (eg Sentinel
X100). Your warranty is at risk if an
incorrect water treatment product is used in
conjunction with this appliance. For more
information, contact Buderus Product
Support Department.
It is most important that the correct
concentration of the watertreatment product
is maintained in accordance with the
manufacturer's instructions.
If the boiler is used in an existing system
any unsuitable additives MUST be removed
by thorough cleaning.
BS.7593:1992 details
the steps necessary to clean a domestic
central heating system.
In hard water areas, treatment to prevent
lime scale may be necessary - however, the
use of artificially softened water is NOT
permitted.
Under no circumstances should the boiler
be fired before the system has been
thoroughly flushed.
Do not use water softened in a salt
bedding exchanger.
Do not use inhibitors, anti-freeze or
other additives.
The expansion vessel must be of
sufficient size.
When oxygen-permeable pipes are used
(e. g. for floor heating systems) the system
must be separated by means of heat
exchangers. Unsuitable heating water
promotes sludge formation and corrosion.
This may cause malfunctions and damage
in the heat exchanger.
NOTE:
Notes relating to domestic hot water.
The domestic hot water service must
be in accordance with
BS 5546 and BS
6700
.
The boilers are suitable for connection
to most types of washing machine and
dishwasher appliances.
When connecting to suitable showers,
ensure that:
a. The cold inlet to the boiler is fitted with
an approved anti-vacuum or syphon
non-return valve.
b. Hot and cold water supplies to the
shower are of equal pressure.
Where the water hardness exceeds
150 mg/litre, it is recommended that a
proprietary scale reducing device is
fitted into the boiler cold supply with
the requirements of the local water
company.
CAUTION
Provision must be made to accomodate
the expansion of DHW contained within
the appliance, if a non-return valve is fitted
to the DHW inlet, as detailed in
BS. 6798: 5.4.3.
Page 6
Installation1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
6
1 Installation
1.1 Dimensions, connections and
assembly
800 - 24T25V / 800 - 29T25V 800 - 24 / 800 - 29
800 - 43 / 800 - 60
CH flow
CH return
CWDO
GAS
CH flow
CH return
CWDO
GAS
CH flow
CH return
CWDO
GAS
DHW warm
DHW cold
1250 mm (49 ")
1
5
55 mm (2 ")
1
7
152 mm
(6")
152 mm
(6")
560 mm (22")
335 mm (13 ")
1
7
55 mm (2 ")
1
7
46 (1 ")
4
5
46 (1 ")
4
5
30 (1 ")
1
5
30 (1 ")
1
5
431 mm (17")
431 mm (17")
55
1
7
(2 ")
75
(3")
75
(3")
150
(6")
150
(6")
55
1
7
(2 ")
75
(3")
4 x 75
(3")
150
(6")
152 mm
(6")
46 (1 ")
4
5
30 (1 ")
1
5
431 mm (17")
75
(3")
55
1
7
(2 ")
323
209
(8 ")
1
4
(12 ")
4
3
335 mm
(13 ")
1
7
115 mm
(4 ")
1
2
900
mm (35 ")
1
2
(7 ")
1
2
190
(7 ")
1
2
190
(26 ")
1
5
665 mm
685 mm (27")
685 mm (27")
(7 ")
1
2
190
420 mm
1
2
(16 ")
420 mm
1
2
(16 ")
420 mm
1
2
(16 ")
560 mm (22")
335 mm (13 ")
1
7
DHW warm out = hot water outlet 15 mm dia.
DHW cold in = cold water inlet 15 mm dia.
GAS = gas connection R½ (800 - 24/29/43)
and (800 - 24T25V/29T25V)
gas connection R¾ (800 - 60)
CH return = boiler return line 28 mm dia.
CH flow = boiler flow line 28 mm dia.
CWDO = condensate water drain 32 mm dia.
Page 7
Installation 1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
7
800 - 24T25H / 800 - 29T25H
(7 ")
1
2
190
685 mm (27")
420 mm
1
2
(16 ")
75
(3")
40 (1 ")
1
2
30 (1 ")
1
5
431 mm (17")
75
(3")
55
1
7
(2 ")
335 mm
(13 ")
1
7
115 mm
(4 ")
1
2
900 mm (35 ")
1
2
75
(3")
300
(11 ")
5
4
152 mm
(6")
CH flow
CH return
CWDO
GAS
DHW warm
DHW cold
DHW warm
out
= hot water outlet 15 mm dia.
DHW cold in = cold water inlet 15 mm dia.
GAS = gas connection R½ (800 - 24T25H/29T25H)
CH return = boiler return line 28 mm dia.
CH flow = boiler flow line 28 mm dia.
CWDO = condensate water drain 32 mm dia.
Minimum side clearance required for all boilers is 100 mm (4")
Page 8
Installation1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
8
1.2 Boiler assembly - exploded view
Single unit (type 800 – 24 / 800 – 29)
Legend
10 Casing complete
20 Door
30 Casing clamp
40 Casing seal
50 Back panel
60 Mounting bracket
70 Seal lid for air vent
80 Heat exchanger
90 Revision set for air vent
100 Seal
110 Sight glas complete with
sealing rings
120 Restriction plate
130 Seal for condensate collector
140 Condensate collector incl. seal
150 Sensor complete with O-ring
160 Mounting clip
170 Seal for hot surface ignitor/
ionisation electrode
180 Hot surface ignitor
190 Ionisation electrode with cable and
connector
200 Safety sensor-ntc complete
210 Flue gas collector
220 Lip ring seal DN 80mm
230 Condensate by-pass
240 Syphon complete
260 Safety valve pipe
270 Seal set for syphon
280 Burner housing
290 Burner thermostat 107 °C
300 Burner seal
310 Gas/air distribution plate
320 Secondary gas/air distribution plate
330 Burner plaque assembly
340 Gas/air manifold
350 O-ring gas/air manifold to burner
360 Gas injector, natural gas (G20)
incl. O-ring
370 Air restrictor natural gas (G20)
375 Connection tube, fan/burner
380 Connection tube, fan/burner
430
420
360
340
350
290
280
370
230
220
330
320
310
300
210
70
100
110
90
80
120
260
270
240
60
530
550
560
565
540
545
570
520
510
470
500
480
490
40
30
630
540
640
590
620
610
650
580
600
375
380
410
390
400
460
430
440
170
180
190
200
160
130
140
20
10
150
150
50
660
390 Air inlet pipe incl. gasket
400 Support mounting bracket fan anti
vibration
410 Fan
420 Connection pipe gas valve/burner
430 Connection nipple 3/4"x1/2" with O-ring
440 Gas unit
460 Gas inlet pipe 1/2"
470 Control uba
480 Temperature / pressure gauge
490 Bracket for uba
500 Power switch
510 230V cable
520 Cable harness complete
530 Supply pipe heat exchanger
540 O-ring
550 Spring clip heat exchanger/supply
560 Pressure relief valve
570 Non return valve R 1/4''
580 Pump
590 Gasket for pump DN 44 x 2.5
600 Pump power cable complete with
connector
610 Ring
620 Nut for heat exchanger 1 1/2''
630 Nut for heat exchanger 1 1/2''
640 Return pipe
650 Filling-, draining valve
660 RTH converter
Page 9
Installation 1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
9
1.3 Flue Installation
1.3.1 Siting the flue terminal
The flue must be installed in accordance with the
recommendations of BS. 5440-1:2000.
Pluming will occur at the terminal so terminal positions
where this could cause a nuisance should be avoided.
The air supply and the flue gas exhaust must meet the
applicable general regulations. Please consult the
instructions provided with the flue terminal kits prior to
installation.
The boiler MUST be installed so that the terminal is
exposed to external air.
It is important that the position of the terminal allows the
free passage of air at all times.
Minimum acceptable spacing from the terminal to
obstructions and ventilation openings are specified in
table 1.
If the terminal is fitted within 1000 mm of a plastic or
painted gutter or within 500 mm of painted eaves, an
aluminium shield of at least 1000 mm long should be
fitted to the underside of the gutter or painted surface.
If the lowest part of the terminal is less than 2 metres
above the level of the ground, balcony, flat roof or place
to which any person has access, the terminal must be
protected by a guard. Protective guards are available
from Quinnell Barrett and Quinnell, Old Kent Road,
London.
Ensure that the guard is fitted centrally.
The flue assembly shall be so placed or shielded as to
prevent ignition or damage to any part of the building.
The air inlet/products outlet duct and the terminal of the
boiler MUST NOT be closer than 25 mm (1'') to
combustible material. Detailed recommendations on the
protection of combustible material are given in BS.
5440- 1:2000.
If this could occur the appliance MUST be turned off
(with the owners permission), and labelled as unsafe
until corrective action can be taken.
fig. 1 Flue terminal position
A
A
F
M
G
M
B,C
F
F
B,C
K
G
K
K
G
C
L
L
FJ
K
G
D
H, I
under carport
Terminal Position
Minimum
Spacing
A. Directly below or alongside an opening
window, air vent or other ventilation opening
300 mm (12")
B. Below guttering, drain pipes or soil pipes
75 mm (3")
C. Below eaves
200 mm (8")
D. Below balconies or a car port roof
200 mm (8")
E. From vertical drain pipes or soil pipes
150 mm (6")
F. From internal or external corners
300 mm (12")
G. Above adjacent ground, roof or balcony level
300 mm (12")
H. From a surface facing the terminal
600 mm (24")
I. From a terminal facing a terminal
1200 mm (48")
J. From an opening in a car port (e.g. door or
window) into dwelling
1200 mm (48")
K. Vertically from a terminal on the same wall
1500 mm (60")
L. Horizontally from a terminal on the wall
300 mm (12")
M. Adjacent to opening
300 mm (12")
table 1 Balanced flue terminal position
NOTE
It is absolutely essential to ensure, in
practice, that products of combustion
discharging from the terminal cannot reenter the building or any other adjacent
building through ventilators, windows,
doors, other sources of natural air
infiltration, or forced
ventilation/airconditioning.
Page 10
Installation1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
10
1.3.2 Air supply and flue gas exhaust in a closed
installation
To ensure optimal operation, the 800 Series appliances
must be connected to a Buderus wall-mounted or roofmounted flue terminal. These terminals have been
developed specifically for the 800 Series condensing
gas boilers and have been comprehensively tested. The
Buderus wall and roof-mounted flue terminal kits ensure
trouble-free operation.
The following items for the flue (see fig. 2) are included
in the delivery of the boiler:
– pos. 1: 1 Concentric bend 80/125;
– pos. 2: 1 Horizontal flue terminal 80/125;
– pos. 3: 1 Flue finishing kit.
1.3.3 Maximum Flue length
The maximum pipe length of the air supply and flue gas
exhaust pipes for the 800 Series condensing gas boilers
(see table 2) is determined by the total pressure loss of
all components in the flue gas exhaust / air supply
system.
Maximum wall thickness without extensions is 550 mm.
Maintain a minimum side wall clearance of 50 mm (see
fig. 3).
1.3.4 Additional flue parts
Additional flue parts (see table 3) can be ordered from
your supplier.
fig. 2 Horizontal flue pack
1
2
3
fig. 3 Side flue and rear flue installation
550 mm
50 mm
L
Boiler
Maximum
pipe length
For every 90° bend the
maximum pipe length has
to be reduced by
800 – 24 / 24T25 H/V L = 14 m 0 m
800 – 29 / 29T25 H/V L = 14 m 0 m
800 – 43 L = 14 m 1.5 m
800 – 60 L = 9 m 1.5 m
table 2 Pipe length
Flue parts Order No.
Concentric pipe, 500 mm long, adjustable NE 83713
Concentric pipe, 1000 mm long, adjustable NE 83714
Concentric bend 90° NE 83715
Concentric bend 45° NE 83716
24-43 kW adaptor plate NE 79061
60 kW adaptor plate NE 79064
table 3 Additional flue parts
Page 11
Installation 1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
11
1.4 Items supplied with unit
Check the contents against the packing list to ensure
that nothing is missing.
Requirements to be met by the place of installation
1.5 Gas boiler
Remove the packing and discard to ensure proper
recycling.
Do not remove the polystyrene foam bottom slab
protecting the connection nozzles. During installation
the gas boiler and the flue gas adapter must be
protected to prevent site dirt from entering, e.g. using
aluminum foil.
Fit the wall bracket.
Removing the casing:
Open the cover of the control panel (fig. 5, item 1).
fig. 4 Items supplied with unit
Key to fig. 4:
1: wall-mounted condensing gas boiler
2: wall bracket
3: technical documents
4: wall-mounting template
5: screw fittings for connecting the boiler (heating system)
gas service valve ½" (800-24/29/43)
gas service valve ¾" (800-60)
2
3
5
1
4
6
NOTE
Observe all statutory building regulations
applying to the place of installation.
DANGER!
Inflammable materials or liquids must not be
stored or used near wall-mounted
condensing gas boilers. The site of
installation must be frost-protected.
fig. 5 Removing the casing
6
1
2
5
5
5
4
3
NOTE!
Note the clearance required to install the
flue system (see chapter 1.8 "Flue
installation").
Note the side wall minimum clearance of
100 mm. If a storage-type water heater is
installed underneath, take care that the
minimum clearances according to the
installation instructions are adhered to.
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Installation1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
12
Remove the screw (fig. 5, item 2).
Open the locks (fig. 5, item 3) with the radiator key
(fig. 5, item 4).
Release the clasps (fig. 5, item 5).
Remove the boiler casing forwards (fig. 5, item 6).
Do not carry the casing by the clasps !
Combination unit type 800 - 24T25V / 29T25V:
Vertical boilers:
Pull forward the casing of the hot water reservoir and
lift it clear from the top holders. This is only possible
with the upper casing removed.
Attach the gas boiler to the wall bracket (fig. 6).
1.6 Water circulation system
The central heating system should be in accordance
with BS.6798 and, in addition, for smallbore and
microbore systems, BS.5449.
1.7 Pipe connections
1.7.1 Heating circuit connection
On type 800 – 60 an automatic air-release valve must
be fitted in the return line.
A servicing valve has to be installed in the flow and
return lines to allow the gas boiler to be serviced and
repaired.
Make sure that the expansion vessel, pressure relief
valve and draining valve are installed between the
service valve and the boiler.
In order to ensure an optimum and efficient operation of
the heating system, care must be taken that the heating
boiler always has the required minimum amount of
circulation water.
In single-circuit systems the required minimum amount
of circulation water can be provided e.g. by means of an
bypass valve.
A bypass valve is not needed when a hydraulic shunt is
installed.
fig. 6 Installation
Page 13
Installation 1
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
13
Thoroughly flush pipes and radiators !
For sizes of pipe connections please refer to the wall
mounting template.
Fit expansion vessel in compliance with the separate
installation instructions
or
install the expansion vessel in the boiler return line.
Fit the service valve in the flow and return lines (see
subsection 1.1 on pages 6 and 7).
Connect pipes free of tension.
1.7.2 Gas Supply
The gas installation must be installed in accordance with
BS6891.
The complete installation MUST be tested for gas
tightness and purged as described in IGE/UP/1b.
1.7.3 Gas connection
For the size of the pipe connection please refer to the
wall mounting template.
Connect the boiler to the gas supply in accordance
with the relevant standards. Fit the supplied service
valve in the gas feed line. Connect the pipe free of
tension (fig. 7).
Fit a gas service valve with a size of R¾ on type 800 –
60.
1.7.4 Hot water connection
On type 800 – 24/29/43/60:
Connect the external storage-type water heater in
accordance with the appropriate installation instructions
using the connection kit.
fig. 7 Gas connection
CAUTION!
Pipework from the meter to the boiler MUST
be of adequate size.
CAUTION!
Work on gas-bearing components may only
be carried out by a Gas Safe registered
installer.
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14
On type 800 – 24T25 H/V and 800 – 29T25 H/V:
When using plastic pipes, note the information provided
by the pipe manufacturer. This particularly applies to the
mode of connection recommended by manufacturer.
In certain situations to prevent hammering within the
system when closing taps, controls can be installed
to counter act this action. For further information
please contact Buderus.
For the size of pipe connections please refer to the
wall mounting template.
1.7.5 Condensate water drain
When shorter aluminium flue-gas systems are used
There is no integrated condensate water outlet in the
flue gas adapter of the aluminium exhaust flue.
The condensate water from the exhaust flue flows via
the gas boiler and into the boiler's odour trap (syphon,
see fig. 10).
fig. 8 Hot water connection vertical boilers
(type 800 – 24T25V / 800 – 29T25V)
CAUTION!
Do not use galvanised pipes or fittings. The
hot water heat exchanger is made of copper
and risks electrolytic corrosion.
fig. 9 Hot water connection horizontal boilers
(type 800 – 24T25H / 800 – 29T25H)
fig. 10 Condensate water outlet for exhaust flue systems
made of aluminium
NOTE!
The condensate water collecting in the gas
boiler and possibly in the flue gas line must
be drained. Local regulations must also be
noted.
CAUTION!
If the flue gas adapter is made of aluminium,
the sealing cap (fig. 12, item 1) MUST NOT
be removed.
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15
When longer aluminium flue-gas systems are used
There is no integrated condensate water outlet in the
flue gas adapter of the aluminium exhaust flue.
The condensate water from the exhaust flue flows via
the external condensate water outlet with odour trap
(syphon, see fig. 11).
This additional component is required:
– from 10 m expanded overall length of exhaust flue
with 800 Series to boiler size of 24 kW or
– from 5 m expanded overall length of exhaust flue with
type
800 – 29, 800 – 43 and 800 – 60.
1.8 Flue installation
The only flue systems that may be used are those
supplied by Buderus. The flue system must be installed
in accordance with the requirements of BS5440:1. 2000.
Standard 125 mm flue systems
See subsection 1.3.3 for the maximum horizontal
straight length of each type boiler. Full instructions for
fitting this flue are in Section 1.8.2: "Installation of the
horizontal flue“ on page 16.
fig. 11 Condensate water outlet for longer exhaust flue
systems made of aluminium
CAUTION!
If the flue gas adapter is made of aluminium,
the sealing cap (fig. 12, item 1) MUST NOT
be removed.
fig. 12 Remove sealing cap on condensate water bypass
(applies only to boiler connection pieces made of
plastic)
1
2
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1.8.1 Fitting the boiler's adaptor plate
Place the boiler's adaptor plate onto the boiler
(fig. 13).
Secure with 6 screws.
1.8.2 Installation of the horizontal flue
The standard 125 mm diameter horizontal flue system is
suitable for length upto 595 mm. Flue length above this
will require extension duct assemblies.
See table 2 on page 10 for the maximum pipe length for
each type boiler.
fig. 13 Adaptor plate
IMPORTANT
Any horizontal flue system fitted to a
condensing boiler must be incline towards
the appliance at an angle of 3% (30 mm per
metre length) to prevent condensate
dripping from the flue terminal.
This means that the clearance above the
appliance must be increased to match the
duct length. See figure on page 6.
fig. 14 Elbow with flue gas testing point
fig. 15 Standard flue
Flue
Turret
Maximum 595 mm
Terminal
assembly
Outer
Wall
NOTE
Use the wall-mounting template to help you
mark the position of the side flue opening
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1.8.3 Flue duct preparation and assembly
Measure the flue length L. Refer to figure 16.
Mark of the lengths shown onto the ducts and cut the
length. The cuts must be square and free from burrs.
Terminal assembly outer (air) duct - L-70 mm, inner (flue)
duct - L-50 mm. The measurement is made from the ridge
at the terminal indicating the outer face of the wall.
Refer to figure 18.
Extension air duct - L-70 mm, flue duct - L-50 mm.
The measurement is from the formed end.
Assemble flue system completely. Push the ducts
fully together. The slope of the terminal outlet must
be face downwards.
The assembly will be made easier if a solvent free
grease is lightly applied to the male end of the ducts.
Push the assembly through the wall and slide the tur-
ret onto the flue connector. Refer to figure 14.
Ensure that the turret is fully entered into the socket
on the boiler. From the outside fix the flue finishing kit
to the terminal and, after ensuring the duct is properly
inclined towards the boiler, fix the finishing kit to the
wall.
If the terminal is within 2 m of the ground where there
is access then an approved terminal guard must be
fitted.
The guard must give a clearance of at least 50 mm
around the terminal and be fixed with corrosion resistant screws.
fig. 16 Flue length - rear
152
L
NOTE
The flue must be inclined to the boiler.
fig. 17 Flue length - side
L
NOTE
An inner wall sealing plate is provided which
should be fitted to the ducts before
assembly.
fig. 18 Flue terminal position
Outer
Wall
Face
Flue Terminal
Raised Ring
locating the
terminal relative
to the outside
wall face
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1.9 Electrical connections
1.9.1 Mains connection
A mains supply of 230 V - 50Hz is required.
External controls are suitable for volt free or 230 V
installation.
Wiring to the boiler MUST be in accordance with the
current I.E.E. (BS.7671) Wiring Regulations and any
local regulations.
Wiring should be a 3 core PVC insulated cable, not less
than 0.75 mm
2
(24 x 0.2 mm), and to table 16 of
BS.6500.
Connection must be made in a way that allows complete
isolation of the electrical supply such as a double pole
switch having 3 mm (1/8'') contact separation in both
poles, or by a three pin connector, serving only the boiler
and system controls. This boiler is equipped with a
double pole switch see fig. 19, item 1. The means of
isolation must be accessible to the user after installation.
The electrical connection to the mains supply should be
readily accessible and adjacent to the boiler.
If the supply cord is damaged, it must be replaced by a
registered Gas Safe installer to avoid a hazard and must
be an original spare part.
The electrical supply for both the boiler and the system
must
be taken from the same fused spur outlet.
fig. 19 UBA
1
NOTE
All Buderus boilers require a permanent
live.
WARNING!
Do not connect 230V to the connection
block on the UBA.
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19
1.9.2 Wiring Diagram
fig. 20 Wiring diagram
24 VAC
0 VAC
0
max 6 VA
12
RC
1)
12
Incandescent
firing electrode
Remove bridge when
carrying out connection
12
1234
M
N
L
12
M
231
1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
20 pin connection strip 18 pin connection strip
12 34 56 78 9 1110
24V output (AC)
External sensor
Fuse, main switch, emergency OFF switches and safety
measures to comply with local regulations and standards
STB
MV2
MV1
HT1
HT2
24Vdc
ATB
PA
FR FS
FB
FK
Flame-monitoring electrode
Note:
Circulation pump (PH)
(max. 2A)
KIM
Ventilator
230V 50Hz
Mains power source
~
1) Only one room-temperature regulating
device may be connected.
ATB Flue-gas temperature-limiting device
FB Mains-water temperature sensor
FK Boiler water-temperature sensor (supply)
FR Return-temperature sensor (return)
FS Safety-temperature sensor (safety)
HT Hand-held terminal
KIM Boiler identification module
MV1 1. Solenoid valve
MV2 2. Solenoid valve
PA Potential-free connection (br idge connector)
STB Burner thermostat
Internal three-way
reversing valve
for mains water
(AC operation)
Digital Room
Controller
I/O
communication port
Turn-on voltage for
external, customer-supplied
three-way reversing valve
(AC operation)
Bridge is conductive
(remove when connecting)
Loop is non-conducting
(remove when connecting)
UBA connection block
Burner-control unit (UBA)
Fuse 1.25 slow blow
21
2
1
1
2
12
external
230V controls
Volt free external
control device
*) remove wirebridge
when used
Volt free room
thermostat
when used with
230V timer *)
IMPORTANT
The wires in this mains lead are coloured in accordance with the following code:
GREEN AND YELLOW - EARTH ; BLUE - NEUTRAL ; BROWN - LIVE
As the colours of the wires in the mains lead of of the appliance may not correspond with the coloured markings identifying the terminals in your plug proceed as follows:
The wire coloured green and yellow must be connected to the terminal on the plug marked with the letter E or by the earth symbol or coloured green or green-and-yellow. The wire coloured brown must be connected to the terminal marked with
the letter L or coloured red. The wire coloured blue must be connected to the terminal marked with the letter N or coloured black.
WARNING
THIS APPLIANCE MUST BE EARTHED
Ensure that your appliance is connected correctly - if you are in any doubt consult a qualified electrician.
WARNING!
Do not connect 230V to the connection block on the UBA.
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1.9.3 Connecting a three-way valve of an external
storage-type water heater
Three-way valve with plug:
Connect the plug-and-socket connector to the plug of
the external storage-type water heater (fig. 21).
Three-way valve without plug:
Connect the three-way valve to terminals 9 and 11 of
the terminal strap (fig. 22, item 5).
1.9.4 External controls
The wall-mounted condensing gas boiler can be fitted
with the following control devices:
– Buderus programmable room thermostat
(see subsection 1.9.5).
– A room-temperature control device at 230V
connected to the RTH converter (see subsection
1.9.6);
– ON/OFF temperature controller, volt free
(see subsection 1.9.7);
fig. 21 Connecting a three-way valve of an external storage-
type water heater
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21
If the boiler has to be temporarily put into operation
without control unit, place a conducting bridge in
terminal 12 and set the feed temperature and the
required heating capacity on the UBA.
1.9.5 Buderus room temperature control device
connection
Remove the bridge in terminal 34 (fig. 22, item 2)
and connect the control unit to the terminal strap.
Remove the wire in terminal 12 (fig. 22, item 1).
1.9.6 230V room-temperature control device connection
Remove the cover of the RTH converter (fig. 22,
item 6).
Lead the control device wire through the cable lead
(fig. 22, item 8).
Fix the wire to terminal 1 and 2 of the 230 Volt con-
nection (fig. 22, item 9).
Secure the wire with the bracket and the two screws
onto the RTH converter.
1.9.7 Volt free external control device connection
Remove the cover of the RTH converter (fig. 22,
item 6).
Lead the control device wire through the cable lead.
Fix the wire to terminal 1 and 2 of the volt free con-
nection (fig. 22, item 10).
1.9.8 Service tool
The service tool allows you to determine the operating
status of the boiler, check components and carry out fast
fault
diagnosis.
Open the flap at the front of the boiler unit and insert
the twin plug connector of the service tool into the
sockets provided (fig. 23, item 1).
fig. 22 Connecting the control unit
Key to fig. 22:
item 1: ON/OFF temperature controller (non-conducting
bridge)
item 2: Room temperature controller iRT (digital)
item 3: I/O port/communication port
item 4: Outdoor temperature sensor
item 5: Power supply 24 VAC/max: 6 VA switching voltage
three-way valve (9+11)
item 6: RTH converter
item 7: 24 VAC connection
item 8: 230 VAC connection
item 9: Volt free connection
2
4
5
6
7
8
10
11
12
1
3
1
2
3
4
9
5
6
0 VAC
0 V
24 VAC
- max. 6VA
1
2
3
4
5
6
10
9
7
8
NOTE
RTH converter is no longer in use.
fig. 23 Service-tool connection
1
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1.9.9 System examples
Prog
reference room / main living area
other rooms
CT
ZV
TRV
LSV
LSV
LSV
Cylinder
radiator radiator
AV
WC
RT
CHF CHR
ZV
Condensing gas boiler
Buderus 800
PL
JB
CB
EV
PRV
Prog
reference room / main living area
other rooms
CT
DV
TRV
LSV
LSV
LSV
Cylinder
radiator radiator
AV
WC
RT
CHF
CHR
Condensing gas boiler
Buderus 800
PL
JB
CB
EV
PRV
Boulter Buderus
programmable
room thermostat
reference room / main living area
other rooms
Condensing gas boiler
Buderus 800
PL
JB
CB
BCT
BDV
TRV
LSV
LSV
LSV
Cylinder
radiator radiator
AV
CHF
CHR
EV
PRV
Key to abbreviations :
AV = Air Vent
BCT = Buderus cylinder thermostat
BDV = Buderus diverter valve
CB = Connection Block
CHF = Central Heating Flow
CHR = Central Heating Return
EV = expansion vessel
JB = Junction Box / RTH Relay
LSV = Lockshield Valve
PL = Permanent Live
PRV = Pressure relief valve
TRV = Thermostatic radiator valve
Buderus 800 with Buderus controls
Buderus 800 with external 230V connection
Key to abbreviations :
AV = Air Vent
CB = Connection Block
CHF = Central Heating Flow
CHR = Central Heating Return
CT = Cylinder thermostat
DV = Diverter valve
EV = expansion vessel
JB = Junction Box / RTH Relay
LSV = Lockshield Valve
PL = Permanent Live
Prog = Programmer
PRV = Pressure relief valve
RT = Room Thermostat
TRV = Thermostatic radiator valve
WC = Wiring Centre
Buderus 800 with external 230V connection and two port zone
Key to abbreviations :
AV = Air Vent
CB = Connection Block
CHF = Central Heating Flow
CHR = Central Heating Return
CT = Cylinder thermostat
EV = expansion vessel
JB = Junction Box / RTH Relay
LSV = Lockshield Valve
PL = Permanent Live
Prog = Programmer
PRV = Pressure relief valve
RT = Room Thermostat
TRV = Thermostatic radiator valve
WC = Wiring Centre
ZV = Two port Zone Valve
Page 23
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23
2 Initial start-up
2.1 Preparing the boiler for operation
2.1.1 Filling the heating system
When using oxygen-permeable pipes (e.g. for floor
heating), heat exchangers must be used to separate the
system.
Move the mechanical switch on the three-way valve
to centre position (fig. 24) (applicable for 800-24T25
and
800-29T25 only) and systems with an external storage-type water heater.
If necessary open the CH flow and CH return mainte-
nance valves.
Connect temporary hose of the filling loop (for pipe
locations see page 6 and 7).
Open both stop valves.
Fill the system to a pressure of 1.0 to 1.2 bar (fig. 26,
item 1). Max. water pressure is 2.0 bar.
Shut both stop valves and disconnect the filling loop.
fig. 24 Mechanical switch on the three-way valve
WARNING
The wall-mounted condensing gas boiler
must not be activated at this stage.
fig. 25 Connecting temporary hose
temporary
hose
stop
valve
stop
valve
double
check
valve
DHW
cold
CH
return
fig. 26 Pressure display
12
10
1
01
11
KW
10
1
10
1
I
0
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24
To drain the system take the following steps:
Close the CH flow and the CH return service valve.
Place hose on the draining tule.
Turn to drain the system.
2.1.2 Preparing the automatic air release valve
Open the protective cap on the automatic air release
valve one full turn (fig. 27).
Should the air purging operation cause the pressure
to drop below minimum, top up water.
2.1.3 Filling the hot water reservoir
Open the cold water inlet on the service valve.
Open the hot water valve until a full jet of water is
flowing.
2.1.4 Filling the syphon with water
Pull the hose from the condensate plate (fig. 28,
item1).
Fill the syphon with water.
Fit the hose to the condensate plate.
2.1.5 Checking for leaks
Disconnect the system from power supply.
Check all sections of gas pipework and connections
for signs of leaks before starting up system for the
first time.
If a leak is detected during tightness testing, use an
approved leak detector to check all connections for
possible escapes.
The product must be certified as a gas leak-testing
agent.
DO NOT allow the product to come into contact with
electrical wiring.
fig. 27 Automatic air release valve
fig. 28 Filling the syphon with water
1
2
3
4
5
6
7
8
9
10
24 VAC
- max 6 VA
0
24 VAC
1
2
3
4
5
6
12
11
1
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25
2.1.6 Purging air from the gas supply pipe
Loosen the screw plug on the gas connection and air
purging test nipple on Honeywell gas units two turns
(fig. 29, item 1), fully unscrew the plug on SIT gas
units (fig. 30, item 1) and fit the hose.
Purge system and appliance as per relevent proce-
dures, IGE/UP/1b. Ensuring all safety requirments
are met.
fig. 29 Purging the gas supply pipe (Honeywell gas units)
fig. 30 Purging the gas supply pipe (SIT gas units)
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26
2.2 Start-up work
2.2.1 Checking the boiler equipment
Type of gas Factory setting of gas burners
Natural
gas E
(includes
natural
gas H)
When delivered ready for operation and set
to Wobbe index 14.1 kWh/m
3
(referred to
15 °C, 1013 mbar), applicable for Wobbe
index range 11.3 to 15.2 kWh/m
3
.
Inscription on type of gas label:
Category setting: G 20 2E_20 mbar
Formerly: set to Wobbe index 15.0 kWh/m3
(referred to 0 °C, 1013 mbar), applicable for
Wobbe index range 12.0 to 15.7 kWh/m3.
LPG
After change-over (see Installation
Instructions: “Changing to another type of
gas”) suitable for LPG.
Inscription on type of gas label:
Category setting: 3P G 31_30-50 mbar
table 4 Gas burner factory settings
Gas boiler Type of gas
Gas injector
diameter
[mm]
Air injector
diameter
[mm]
800-24
(24T25 H/V)
Natural gas H 4.65 21.55
LPG 3.45 20.10
800-29
(29T25 H/V)
Natural gas H 5.00 23.30
LPG 3.90 23.00
800-43
Natural gas H 6.40 29.30
LPG 4.85 27.40
800-60 Natural gas H 8.00 36.40
table 5 Gas and air injector diameters
NOTE
The burner must only be put into operation
with the correct injectors (table 5).
Page 27
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27
2.2.2 Settings
Setting the flow temperature
Set the controller (fig. 31, item 2) to the desired max-
imum flow temperature in accordance with the system design and table 6.
Factory setting = 80 C (controller poition 10).
With external storage-type water heater:
set the hot water temperature
Use the controller (fig. 31, item 3) to set the desired
domestic hot water temperature in accordance with
table 7.
fig. 31 Controls
Key to fig. 31
item 1: Main switch
item 2: Flow temperature controller
item 3: Domestic hot water temperature controller
item 4: Jumper 11/50 kW to limit capacity
item 5: Pump over-run time switch
item 6: Heating capacity controller
item 7: Cover for second control level
12
10
01
11
kW
10
10
1
1
123
7
4
5
6
Controller position Flow temperature in °C
140
2 44
348
4 53
558
6 62
767
8 71
976
10 80
table 6 Flow temperature
Controller
position
Domestic hot water temperature of
external reservoir in °C
127
2 31
334
4 38
541
6 45
749
8 52
956
10 60
table 7 Domestic hot water temperature
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Setting the heating capacity
Open the cover of second control level (fig. 31, item
7).
Set the heating capacity in accordance with the re-
quired heat demand (table 8) on the controller
(fig. 31, item 6). Take into account the appropriate
losses caused by the flue gas system (table 9).
Setting the pump over-run time
Move the switch
( (fig. 31, item 4) to position "1".
Pump over-run time 4 minutes.
Move the switch
( to position "2" when the system is
controlled in accordance with the room temperature
and if parts of the system outside the detection area
of the room temperature controller are at risk of freezing (e.g. radiators in the garage).
Pump over-run time 24 hours (constant operation).
Connecting the hot water sensor FW
Remove the bridge plug (fig. 32, item 1).
Cable colours: black/white and lilac.
Connect 3-m long extension cable (fig. 32, item 2) for
the hot water sensor to the plug and fit sensor in the
reservoir.
Con-trol-
ler posi-
tion
Heating capacity in kW (±5 %)
800-24
24T25
800-29
29T25
800-43 800-60
1 6.6 8.4 12.1 22.0
2 8.4 10.8 15.2 25.3
3 10.2 13.0 18.3 29.7
4 11.9 15.2 21.4 33.5
5 13.6 17.5 24.5 37.3
6 15.3 19.7 27.7 41.2
7 17.0 21.9 30.8 45.0
8 18.7 24.1 35.9 48.8
9 20.4 26.3 37.0 52.7
10 22.0 28.0 40.2 56.5
table 8 Heating capacity
Pressure loss of
flue gas system
in Pa
Available portion of
maximum capacity
in %
800-24/29/43 800-60
20 98.5 98.5
30 97.8 98.0
40 97.1 97.4
50 96.4 96.9
60 95.6 96.3
70 94.8 95.8
80 – 95.2
90 – 94.7
table 9 Capacity losses
fig. 32 Hot water sensor FW for external storage-type water
heater
1
2
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29
type 800 – 24T25 H/V and 800 – 29T25 H/V
Setting the hot water flow limiter
Set the desired value on the flow volume limiter
(fig. 33), e.g. for 60 °C at 6 liters/min for type 800 –
24T25 or 8 liters/min for type 800 – 29T25.
2.2.3 Measuring the gas supply pressure (flow pressure)
Open at least one radiator thermostat valve.
The gas boiler must not be turned on yet.
Move the chimney sweeper switch (fig. 34) to posi-
tion "1".
On type 800 – 60 the full capacity is achieved after
approx. one minute. Therefore measurements
should be carried within one minute of boiler operation.
Loosen the screw plug on the gas distribution pres-
sure test nipple on Honeywell gas units (fig. 35,
item 1) two turns, fully unscrew the plug on SIT gas
units (fig. 36, item 1).
Fit the measuring hose of the pressure gauge to the
test nipple (fig. 35, item 2 or fig. 36, item 2).
Slowly open the gas service valve.
Insert the mains plug and move the mains switch to
"I". After about 30 seconds the burner will fire.
Measure the gas distribution pressure and enter into
the certificate.
The gas distribution pressure must be
min. 17 mbar, max. 25 mbar, rated distribution
pressure 20 mbar for natural gas H and
min. 30 mbar, max. 50 mbar, rated distribution
pressure 37 mbar for LPG.
Pull off the measuring hose and tighten up the screw
plug on the test nipple.
fig. 33 Hot water flow volume limiter
Turning to the right = reducing the flow volume
Turning to the left = increasing the flow volume
fig. 34 Chimney sweeper switch
12
10
01
11
KW
10
1
10
1
01
1
I
0
fig. 35 Measuring the gas distribution pressure
(Honeywell gas units)
Page 30
Initial start-up2
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30
Ensure all disturbed joints and connections are checked
for gas tightness on completion of tasks.
2.2.4 Checking and setting the gas/air ratio
The gas/air ratio can be checked and set in two different
ways:
– using a pressure gauge;
– in accordance with the CO
2
content.
Setting the gas/ratio using a pressure gauge:
Move the mains switch and chimney sweeper switch
to "0".
Pull off the bottom hose attached P1 (fig. 38, item 1)
and fit a hose with Tee in between.
Connect the Tee to the negative port of the pressure
gauge.
Loosen the screw in the burner pressure measuring
nipple on Honeywell gas units (fig. 38, item 2) two
turns, completely unscrew the screw on SIT gas units (fig. 39, item
1).
Connect the positive port of the pressure gauge with
a hose to the burner pressure measuring nipple
(fig. 38, item 2 or fig. 39, item 1).
Move the mains switch to "I" and the chimney sweep-
er switch to "1".
When the burner has fired after approx. 30 seconds,
press the service button (fig. 37) until "Y" is shown on
the display.
fig. 36 Measuring the gas distribution pressure (SIT gas
units)
NOTE
If the required connection pressure is not
available or too high, contact your gas
supplier or TRANSCO.
fig. 37 Service button
fig. 38 Checking and adjusting the gas/air ratio (Honeywell
gas unit)
2
3
1
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31
Move the hot water temperature controller to "1".
Read the differential pressure.
The differential pressure (p
Gas
- p
Air
) must be -5 Pa
(±5 Pa) (display on the meter: -10 to 0 Pa).
In case of gas/air ratio deviations, adjust by using the
setscrew (fig. 38, item 3 or fig. 39, item 2).
Set mains switch and chimney sweeper switch to "0".
Remove the measuring equipment, tighten up the
screw in the burner pressure measuring nipple, put
the hose back on P1.
Set the hot water temperature controller back to the
original value.
Move the mains switch to "I".
Adjustment according to the CO
2
content (natural
gas):
The mains switch must be set to "I" and the chimney
sweeper switch to "1".
Press the service button (fig. 37) until "Y" is shown on
the display.
Full load
Move the hot water temperature controller to "10".
Measure and record the CO
2
content on the flue gas
measuring point (fig. 40).
Partial load
Set the hot water temperature controller to "1".
Measure and record the CO
2
content.
The CO
2
content under partial load must be 0.7 %
lower than the one under full load.
If the measured value is too high or too low, use the
setscrew of the gas burner unit (fig. 38, item 3 or
fig. 39, item 2) to set the gas/air ratio under partial
load.
Set the hot water temperature controller to the origi-
nal value.
Set the chimney sweeper switch to "0".
2.2.5 Checking for leaks in operational condition
Check with the burner running, all joints across the
entire gas route of the burner using a foaming agent.
The agent must be certified as a gas leak test agent.
Do not apply the agent to electrical connection cables.
fig. 39 Checking and adjusting the gas/air ratio (SIT gas
unit)
1
2
fig. 40 Flue gas measuring point
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2.2.6 Measuring the carbon monoxide content
Measuring point see fig. 40 on page 31.
The carbon monoxide values under vacuum must be
smaller than 400 ppm and/or 0.04 Vol%.
Values around or exceeding 400 ppm indicate a faulty
burner adjustment, a dirty gas burner or heat exchanger
or a defective burner.
Find and eliminate the cause.
2.2.7 Checking the operation
During commissioning and the annual inspection and
servicing routine the working order of all control,
regulating and safety devices must be checked to see if
they are correctly set (provided these devices can be
adjusted).
Measuring the ionisation current
Move the mains switch to "0".
Loosen the plug-and-socket connector of the moni-
toring cable and connect the measuring device in series (fig. 41).
Select on the measuring device the µA direct current
range. The measuring device must have a resolution
of at least 1 µA.
Move the mains switch to "I" and the chimney sweep-
er switch to "1".
After the burner has fired, press the service button
(fig. 37) until "Y" is shown on the display.
Move the hot water temperature controller to "1".
Measure the ionisation current. The ionisation cur-
rent must be > 2 µA direct current under partial load.
Enter the measurement in the certificate.
Move the mains switch to "0".
Remove the measuring device and restore the origi-
nal condition of the plug-and-socket connection.
Move the chimney sweeper switch to "0".
Close the cover of the 2nd control level.
Set the temperature on the hot water temperature
controller to the desired value.
Move the mains switch to "I".
When the display shows "7" and the service button is
pressed, the display turns to "c".
Press the reset button until "r" is shown on the display.
Close the cover.
fig. 41 Measuring the ionisation current
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2.2.8 Fitting the boiler casing
Put the casing in place (fig. 42, item 1).
Close (fig. 42, item 2) and lock the clasps (fig. 42,
item 3) with the radiator key (fig. 42, item 4).
Turn in the screw (fig. 42, item 5).
Close the cover of the control panel (fig. 42, item 6).
Do not carry the casing by the clasps !
2.2.9 Handing over
After completing the installation and commissioning of
the system the installer should hand over to the
householder by the following actions:
Fill out the form at the end of this manual. This con-
firms that the system is properly set up, installed and
commissioned and that it has been handed over in
good working order.
Hand the User Manual to the householder and ex-
plain his/her responsibilities under the relevant national regulations.
Explain and demonstrate the lighting and shutting
down procedures.
The operation of the boiler and the use and adjust-
ment of all system controls should be fully explained
to the householder, to ensure the greatest possible
fuel economy consistent with the household requirements of heating. Advise the User of the precautions
necessary to prevent damage to the system and to
the building in the event of the system remaining inoperative during frosty conditions.
Explain the function and the use of the boiler heating
controls.
Explain the function of the boiler fault mode. Empha-
sise that if a fault is indicated, the boiler should be
turned off and a registered local heating installer consulted.
Explain and demonstrate the function of time and
temperature controls, radiator valves etc., for the
economic use of the system.
fig. 42 Fitting the boiler casing
6
5
2
2
2
4
3
1
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Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
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3 Inspection
3.1 Preparing the heating boiler for
inspection
Disconnect the system.
Remove the burner housing or cover from the heat-
ing boiler (fig. 5 on page 11).
3.2 Checking for internal leaks
Check all internal pipework and controls for leaks using
the appropriate methods as in IGE/UP/1b, using the
correct leak detection fluid. Please ensure that any leak
detector fluid DO NOT come into contact with any
electrical components.
3.3 Visual inspection
Check all gas-bearing and water-bearing pipes for
signs of corrosion (fig. 43).
Replace corroded pipes if necessary.
For further information, please refer to subsection 7.2
"Inspection and service reports" on page 68 and fill out
the
Benchmark.
DANGER OF FATAL INJURY
due to electric shock when system is
opened.
Before opening the system:
disconnect the heating unit at the emergency OFF switch or the corresponding
circuit breaker of the house power supply.
Ensure that the heating system cannot
be reconnected by accident.
NOTE
If the gas supply pipes are to be
disconnected from the burner, the housing
MUST ONLY be removed by a qualified
service technician and checked for
tightness on reassembly.
fig. 43 Visual inspection for signs of corrosion
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Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
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4 Maintenance
For further information, please refer to subsection 7.2
"Inspection and service reports" on page 68 and fill out
the Benchmark.
Preparations
Disconnect the system from the power supply.
Close the gas service valve.
Remove the boiler casing (fig. 5 on page 11).
4.1 Cleaning the heat exchanger, burner
and syphon
The heat exchanger can be cleaned with a brush and
compressed air.
Loosen the screw couplings of the gas injector
(fig. 44, item 1).
Pull off the hose leading to the fan (fig. 44, item 2).
Pull off the hoses at the differential pressure measur-
ing point (fig. 44, item 3).
Pull off the wiring of the burner thermostat (fig. 44,
item 4).
Pull off the plug of the fan (fig. 45, item 1).
Turn and pull out the safety retainer of the fan
(fig. 45, item 2).
fig. 44 Disconnecting
1
2
10
0
1
11
KW
1
0
1
1
0
1
4
1
3
2
1
2
fig. 45 Removing the fan
1
2
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36
Push up the fan (fig. 46, item 1).
Pivot the lower end of the fan forward (fig. 46, item 2)
and take it out downwards and forwards (fig. 46, item
3).
Loosen both retaining clamps (fig. 47, item 2) of the
burner cover and remove the burner cover and burner
(fig. 47, item 3).
Cleaning by using a brush and compressed air
Pull the syphon away from the condensate plate
(fig. 47, item 1).
Loosen the connection to the condensate water by-
pass
(fig. 47, item 6).
Loosen the retaining clamps (fig. 47, item 4) of the
condensate plate and remove the condensate plate
(fig. 47, item 5).
Pull out the baffle plate (fig. 48).
fig. 46 Removing the fan
1
2
3
fig. 47 Removing the cover and condensate plate
3
2
1
2
3
4
5
6
7
8
9
10
24 VAC
- max 6 VA
0
24 VAC
1
2
3
4
5
6
12
1
5
11
4
6
fig. 48 Baffle plate
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Clean the burner with a soft brush and compressed
air (fig. 49).
Clean the heat exchanger with a rib comb and com-
pressed air.
Put all components back in place in reversed order.
Remove and clean the syphon (fig. 51).
Take care that the syphon cap is screwed on correctly.
Fill with water before putting the syphon back in
place.
Put all components back in place in reversed order.
When plastic boiler connectors are used:
check the operation of the condensate water bypass
Inject water (e.g. using a spray bottle) into the left-
hand flue gas measuring point (fig. 51) and check
that the
condensate water bypass is not obstructed.
fig. 49 Cleaning the burner
1
NOTE
The perforated plate (fig. 49, item 1) is only
provided on type 800 – 24 and 800 – 24T25
models.
fig. 50 Cleaning the heat exchanger
1
DANGER!
The hot surface ignitor (fig. 50, item 1) is
made of fragile material.
fig. 51 Checking the operation of the condensate water
bypass
1
2
3
4
5
6
7
8
9
10
24 VAC
- max 6 VA
0
24 VAC
1
2
3
4
5
6
12
11
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When aluminium boiler connectors are used:
check the sealing cap of the condensate water
bypass.
Visual inspection to see if there is a white sealing cap
on the condensate water bypass (fig. 52).
fig. 52 Condensate water bypass sealing cap
1
2
10
0
1
1
1
K
W
10
1
10
1
1
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Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
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5 Servicing
5.1 Operating codes
NOTE
If the code displayed on the burner-control
unit is not listed under the operating codes
or fault warnings, the burner-control unit
itself is malfunctioning.
Display
Display after
pressing the ser-
vice button
Meaning
0
800 Series is ready for operation
A
Burner interval circuit, 10 minutes from start of burner
C
Waiting for the three-way valve and/or pump to switch
H
Ready for operation
L
First safety period
P; U
Safety period
Y
Flow water temperature setting reached (switching difference +2 K)
-.
800 Series runs in heating mode
A
Chimney sweep mode
H
Normal heating mode
Y
Service mode
=.
800 Series runs in hot water mode
H
Normal hot water mode
r
Reset (after reset button has been pressed for 5 sec. UBA is reset to the switch-on
condition)
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5.2 Fault codes
Code Meaning
1C Flue gas thermostat (STB) has been tripped
Possible
cause
Action
1 Water pressure is too low in the installation Top up the system (see subsection 2.1.1)
2 Connection in cable harness defective or is getting too
hot
Check cable harness and press "reset" until "r" appears in
the display
3 Flue gas thermostat if present is defective or is getting
too warm
Check the cable connections and press "reset" until "r"
appears in the display. Replace if necessary
Code Meaning
2C Safety sensor exceeds 95 °C, blocked for 30 sec.
Possible
cause
Action
1 Resistance in the installation is too high Check if not all (thermostatic) radiator valves are clogged
with dirt. Bypass is installed incorrectly
2 Safety sensor is faulty Measure if resistance over the sensor is correct.
If not replace safety sensor temporarily with another one
(see subsection 5.3.9 and subsection 5.3.10)
3 Problem with the pump or pump cabling
(no circulation)
Check if the pump cabling is faulty or if the pump is stuck
(see subsection 5.3.7)
4 Water pressure is too low in the installation Top up the system (see subsection 2.1.1)
Code Meaning
2F Temperature difference between the safety sensor and flow sensor is greater than or equal to 15 °K,
blocked for 30 sec.
Possible
cause
Action
1 Resistance in the installation is too high Check if not all (thermostatic) radiator valves are closed or
clogged with dirt
2 Safety sensor is dirty or faulty Check the safety sensor for dirt. Measure if resistance over
the sensor is correct. If not replace safety sensor
temporarily with another one (see subsection 5.3.9 and
subsection 5.3.10)
3 Flow sensor is dirty or faulty Check the sensor, replace if necessary by temporarily
connecting another one (see subsection 5.3.9 and
subsection 5.3.10)
4 Problem with the pump or pump cabling
(no circulation)
Check if the pump cabling is faulty or if the pump is stuck.
Replace pump if necessary (see subsection 5.3.7 and
subsection 5.3.8)
5 Water pressure is too low in the installation Top up the system (see subsection 2.1.1)
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Code Meaning
2P Safety sensor rises faster than 5 °C/sec., blocked for 30 sec.
Possible
cause
Action
1 Resistance in the installation is too high Check if not all (thermostatic) radiator valves are closed or
clogged with dirt
2 Safety sensor is dirty or faulty Check the safety sensor for dirt. Measure if resistance over
the sensor is correct. If not replace safety sensor by
temporarily with another one (see subsection 5.3.9 and
subsection 5.3.10)
3 External domestic hot water tank is too small for the
boiler's capacity
Top up the system (see subsection 2.1.1)
Code Meaning
2U Temperature difference between the flow and return sensors is too high, blocked for 30 sec.
Possible
cause
Action
1 Resistance in the installation is too high Check if not all (thermostatic) radiator valves are closed or
clogged with dirt
2 Problem with the pump or pump cabling
(no circulation)
Check if the pump cabling is faulty or if the pump is stuck
(see subsection 5.3.7)
3 Water pressure is too low in the system Top up the system (see subsection 2.1.1)
4 Return sensor is defective or the cabling is faulty Measure the resistance of the sensor
(see subsection 5.3.12)
Code Meaning
4A Flow sensor exceeds 100 °C
Possible
cause
Action
1 Flow sensor is dirty or faulty Check the sensor, replace if necessary
(see subsection 5.3.9 and subsection 5.3.10)
2 There is a problem with the pump or pump cabling
(no circulation)
Check if the pump cabling is faulty or if the pump is stuck.
Replace pump if necessary (see subsection 5.3.7 and
subsection 5.3.8)
3 Water pressure is too low in the installation Top up the system (see subsection 2.1.1)
Code Meaning
4C F2 fuse malfunction, or flue gas thermostat active
Possible
cause
Action
1 Water pressure is too low in the installation Top up the system (see subsection 2.1.1)
2 Heat exchanger is dirty Check for a dirty heat exchanger and clean if necessary
(see subsection 4.1)
3 Flue gas retarder faulty or missing Check if the flue gas retarder is installed in the heat
exchanger
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Code Meaning
4F Flow sensor exceeds 100 °C
Possible
cause
Action
1 Resistance in the installation is too high Check if (thermostatic) radiator valves are clogged with dirt
2 Boiler capacity is too large for the installation Adjust the boiler’s capacity
3 Safety sensor is faulty Check the sensor and measure if resistance over the
sensor is correct. If not replace safety sensor
(see subsection 5.3.9 and subsection 5.3.10)
4 Problem with the pump or pump cabling
(no circulation)
Check if the pump cabling is faulty or if the pump is stuck
(see subsection 5.3.7)
5 Water pressure is too low in the installation Top up the system (see subsection 2.1.1)
Code Meaning
4L Short circuit in safety sensor
Possible
cause
Action
1 Safety sensor is faulty Check the sensor and measure if resistance over the
sensor is correct. If not replace safety sensor
(see subsection 5.3.9 and subsection 5.3.10)
2 A short or bad connection in the cable harness Check the cable harness and/or connector of the sensor
3 UBA might be faulty Check the UBA by temporarily connecting a different UBA
(see subsection 5.3.5)
Code Meaning
4P Safety sensor has a loose connection or is defective
Possible
cause
Action
1 Safety sensor faulty or disconnected Check the sensor and measure if resistance over the
sensor is correct. If not replace safety sensor
(see subsection 5.3.9 and subsection 5.3.10)
2 A short or bad connection in the cable harness Check the cable harness and/or connector of the sensor
(see subsection 5.3.12)
3 UBA might be faulty Check the UBA by temporarily connecting a different UBA
(see subsection 5.3.5)
Code Meaning
4U Short circuit in flow sensor
Possible
cause
Action
1 Flow sensor is dirty or faulty Check the sensor, replace if necessary
(see subsection 5.3.9 and subsection 5.3.10)
2 A short or bad connection in the cable harness Check the cable harness and/or connector of the sensor
(see subsection 5.3.12)
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Code Meaning
4Y Flow sensor interrupted
Possible
cause
Action
1 Flow sensor faulty or disconnected Check the sensor and measure if resistance over the
sensor is correct. If not replace safety sensor
(see subsection 5.3.9 and subsection 5.3.10)
2 A short or bad connection in the cable harness Check the cable harness and/or connector of the sensor
(see subsection 5.3.12)
Code Meaning
5C Boiler shut down after connection with Service Tool
Possible
cause
Action
1 Service tool connection Press reset. If fault code remains than try to temporarily
connect a different UBA (see subsection 5.3.5)
2 A short or bad connection in the cable harness Check the cable harness and/or connector of the sensor
(see subsection 5.3.12)
3 UBA might be faulty Check the UBA by temporarily connecting an other UBA
(see subsection 5.3.5)
Code Meaning
6A F1 fuse defective, or no ionisation message after ignition
Possible
cause
Action
1 There is no flame, ionisation electrode doesn’t
glow, fan is turning
– Check wiring of the hot surface ignitor, measure the resistance
of the hot surface ignitor (should be between 50 and 300 Ohm).
Replace hot surface ignitor if necessary (see subsection 5.3.15
and subsection 5.3.16)
– Check the UBA’s F1 fuse, replace if necessary
2 There is no flame, ionisation electrode does
glow, fan isn’t turning
– Check the fan and KIM connectors and the UBA fuses
3 There is no flame, ionisation electrode and fan
are working
– Check and adjust the gas/air ratio (see subsection 2.2.4)
– Check for 24 V~ on the gas valve during start up
– Check the gas-supply pressure (see subsection 2.2.3), this
should be higher than 20 mbar for natural gas.
– Check the earthing cable connections (yellow/green wire)
– Check the cabling on the ionisation electrode
4 There is a flame, but the flame disappears
when the fan starts up
– Check the gas-supply pressure (see subsection 2.2.3), this
should be higher than 20 mbar for natural gas
– Check and adjust the gas/air ratio (see subsection 2.2.4)
– Check the earthing cable connections (yellow/green wire)
– Check the cabling on the ionisation electrode
– Press reset. If fault code remains than try to temporarily connect
a different UBA (see subsection 5.3.5)
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Code Meaning
6C Ionisation message, but no flame
Possible
cause
Action
1 There is no flame, ionisation electrode doesn’t
glow, fan is turning
– Check wiring of the hot surface ignitor, measure the resistance
of the hot surface ignitor (should be between 50 and 300 Ohm).
Replace hot surface ignitor if necessary (see subsection 5.3.15
and subsection 5.3.16)
– Check the UBA’s F1 fuse, replace if necessary
2 There is no flame, ionisation electrode does
glow, fan isn’t turning
– Check the fan and KIM connectors and the UBA fuses
3 There is no flame, ionisation electrode and fan
are working
– Check and adjust the gas/air ratio (see subsection 2.2.4)
– Check for 24V – on the gas valve during start up
– Check the gas-supply pressure (see subsection 2.2.3), this
should be higher than 20 mbar for natural gas
– Check the earthing cable connections (yellow/green wire)
– Check the cabling on the ionisation electrode
4 There is a flame, but the flame disappears
when the fan starts up
– The gas valve doesn’t close properly. If there is still more than
20 V~ on the gas valve when there is no heat demand then
check the UBA by temporarily connecting a different UBA.
– Check ionisation electrode/circuit (see subsection 2.2.7)
– When both the UBA and the ionisation electrode/circuit are OK,
then replace the gas valve
– Press reset. If fault code remains than try to temporarily connect
a different UBA (see subsection 5.3.5)
Code Meaning
6H Flame dies out after gas valve is opened
Possible
cause
Action
1 Gas/air ratio not in order Check and adjust the gas/air ratio (see subsection 2.2.4)
2 Gas supply pressure may need adjusting Check the gas-supply pressure (see subsection 2.2.3),
this should be higher than 20 mbar for natural gas
3 Earthing cable may be faulty Check the earthing cable connections (yellow/green wire)
4 Ionisation electrode may be faulty Check the cabling on the ionisation electrode
Code Meaning
6L Flame goes out during warm-up phase
Possible
cause
Action
1 Gas/air ratio not in order Check and adjust the gas/air ratio (see subsection 2.2.4)
2 Gas supply pressure may need adjusting Check the gas-supply pressure (see subsection 2.2.3),
this should be higher than 20 mbar for natural gas
3 Earthing cable may be faulty Check the earthing cable connections (yellow/green wire)
4 Ionisation electrode may be faulty Check the cabling on the ionisation electrode
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Code Meaning
7A Voltage in burner-control unit too low (lower than 187 V~) or too high (higher than 246 V~)
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
Code Meaning
7C Mains supply interrupted
Possible
cause
Action
1 A problem with the mains supply Check the mains supply during operation (230V~)
2 Reset button pressed too briefly Press the Reset button until "r" appears in the display
Code Meaning
7F F3 fuse defect, or burner control unit error
Possible
cause
Action
1 Short circuit in the 24V circuit (three-way-valve or
connector)
– Check for a short circuit and replace the F3 fuse
(see subsection 5.3.3)
2 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
Code Meaning
7H Voltage peaks in the UBA
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
Code Meaning
7L Internal UBA error
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
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Code Meaning
8Y Gas fault
Possible
cause
Action
1 External switching contact (e.g. temperature-
monitoring device for underfloor heating has been
tripped or gas pressure too low
Check gas pressure detector is defective or the wires have
not been properly connected to the back of the UBA
(see subsection 5.3.18)
Code Meaning
9A System error
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
2 UBA may be defective – Press reset. If fault code remains then try to temporarily
connect a different UBA (see subsection 5.3.5)
Code Meaning
9C KIM error
Possible
cause
Action
1 Kim connected incorrectly or KIM defective Check the KIM connector and fan connector (see
subsection 5.3.21).
If the connectors are fine then contact Buderus
Code Meaning
9L Gas valve assembly error
Possible
cause
Action
1 Wiring to the gas valve incorrect, or loose wiring
connections in UBA
– Check the electrical connections of the gas valve
– Measure the resistance of the gas valve (18-55 Ohm)
– Check if for example induction fields interfere with the
regulating device
2 UBA may be defective – Press reset. If fault code remains then try to temporarily
connect a different UBA (see subsection 5.3.5)
3 Peaks in the electrical network – Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
Code Meaning
9U KIM defective
Possible
cause
Action
1 Kim connected incorrectly or KIM defective Check the KIM connector and fan connector (see
subsection 5.3.21).
If the connectors are fine then contact Buderus
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Code Meaning
E with
any
character
but P
UBA defective
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
2 UBA may be defective – Press reset. If fault code remains then try to temporarily
connect a different UBA (see subsection 5.3.5)
Code Meaning
EP Non compatible UBA fitted
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
2 Kim connected incorrectly or KIM defective – Check the KIM connector and fan connector (see
subsection 5.3.21).
If the connectors are fine then contact Buderus
Problem: No DHW , despite the system being operational
– Set chimney sweep switch to "0"
– Check three-way valve replace if necessary
– Check DHW sensor and replace if necessary
Problem: No heating, despite that there is a demand for heat and the boiler is operational
– Check regulating device configuration and/or the wiring
– Check the wiring between the regulating device and the UBA (see subsection 5.3.18)
– Check all the wiring
– Check the UBA and replace if necessary (see subsection 5.3.5)
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5.3 Checking and replacing parts
5.3.1 Unblock the 800 Series
Each time a fault has been rectified, push the “reset”
button (fig. 53) and keep it pressed for five seconds. A
letter “r” will appear on the display. After five seconds,
the display returns to “0”. This unblocks the UBA and
returns it to standby mode.
5.3.2 Chimney sweep mode
Certain troubleshooting tasks must be carried out with
the
800 Serie in heating mode. When doing so, the chimney
sweep switch should be set to “1”.
Remember to return the chimney sweep switch to “0”
once work is complete.
Remove cover of control level 2.
Set chimney sweep switch (fig. 54) to “1”.
5.3.3 Checking the fuses
Disconnect the system from the power supply.
Swivel the UBA to one side.
Check fuse for throughput or carry out visual
inspection (fig. 55, items 1, 2 and 3).
If defective, fit new fuse (1.25 AT).
Connect system to mains power supply.
fig. 53 “Reset” button
display
service
reset
pump
reset
servi
12
10
01
11
KW
10
1
10
1
I
0
1
NOTE
The system cannot be unblocked by
disconnecting at the master switch.
fig. 54 Chimney sweep switch
12
10
01
11
KW
10
1
10
1
01
1
I
0
NOTE
The system cannot be used for heating
water while it is in chimney sweep mode.
fig. 55 Checking the fuses
1
2
3
4
5
6
7
8
9
10
24VAC
-max6VA
0
24VAC
1
2
3
4
5
6
12
11
1
2
3
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5.3.4 Check combustion air/flue gas system and hose
connections
Check combustion air/flue gas system for blockages.
5.3.5 Replacing the UBA
Disconnect system from power supply by removing
main fuse or power connection plug.
Swivel the UBA to one side and pull the four-pin plug
of the mains power switch out at the back of the UBA.
Disconnect all plug-in cables. Note the position of
each plug-in cable.
Loosen the three screws on the UBA and remove it.
Remove mains power switch and fit to new UBA.
Screw the replacement UBA into position.
Reconnect all plug-in cables to their correct sockets.
Fit the casing.
Connect system to mains power supply.
Move mains power switch to “I”.
fig. 56 Checking combustion air/flue gas system and
hose connections
fig. 57 Replacing the UBA
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5.3.6 Replacing the fan unit
Loosen the screw couplings of the gas injector
(fig. 58, item 1) and safety valve (fig. 58, item 2).
Pull off the hoses leading to the fan (fig. 58, item 3).
Pull off the hoses at the differential pressure measur-
ing point (fig. 58, item 4).
Pull out the plug of the burner thermostat (fig. 58,
item 5).
Pull out the plug of the fan (fig. 59, item 1).
Turn and pull out the safety retainer of the fan
(fig. 59, item 2).
Push up the fan (fig. 60, item 1).
Pivot the lower end of the fan forward (fig. 60, item 2)
and take it out downwards and forwards (fig. 60,
item 3).
Replace the fan
Reassemble in reverse order.
fig. 58 Disconnecting
1
2
10
0
1
11
K
W
1
0
1
10
1
4
1
3
2
1
2
NOTE
Please refer to fitting instructions for 230 V
fan unit.
fig. 59 Removing safety retainers
1
2
fig. 60 Removing the fan
1
2
3
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5.3.7 Checking the modulating pump
Unscrew the plug on the modulating pump.
Set the mains switch to “I”.
Check to ensure that the modulating pump is run-
ning.
The modulating pump’s running mechanism may become blocked if the heating system has been out of
use for an extended period.
If the modulating pump fails to run:
Set the mains switch to “0”.
Use a spanner to rotate the modulating pump in its
normal running direction. If this fails to unblock the
mechanism, the modulating pump is defective.
If the modulating pump is working correctly, screw
the plug in.
5.3.8 Replacing the modulating pump
Disconnect the system from the power supply
(fig. 62, item 1).
Close maintenance isolating valves.
Drain the 800 Series.
Loosen screws on modulating pump terminal box
and open terminal box (fig. 62, item 2).
Loosen cable (fig. 63, item 1).
Note order of cable terminals.
Loosen modulating pump screw-in adapters and re-
move pump (fig. 62, item 3).
Fit new pump and connect to system (fig. 62, item 4).
Ensure when doing so that the heat-exchanger spacer washer is inserted correctly.
Connect cables in correct order inside terminal box,
close terminal box and screw shut.
fig. 61 Checking the modulating pump
CAUTION!
Water will flow out.
fig. 62 Replacing the modulating pump
1
2
3
2
3
4
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Connect system to mains power supply.
Open maintenance isolating valves.
5.3.9 Checking the flow, return, safety and mains-water
sensors
Unplug cable connection from sensor.
Measure resistance of sensor.
Use a second-reading thermometer to measure the
temperature around the sensor.
Check readings against values shown in table 10
(see page 53). If there is any mismatch, the sensor is
defective.
If the sensor is working correctly, plug it in once
more.
fig. 63 Cable modulating pump
1
NOTE
Fill the 800 Series and purge the system of
air.
fig. 64 Checking the flow/return sensors
fig. 65 Checking the safety sensors
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5.3.10 Replacing the flow, return and safety sensors
Close maintenance isolating valves.
Drain the 800 Series.
Unplug.
Unscrew sensor and replace with new unit.
Plug in cable connection.
Open maintenance isolating valves.
table 10 Resistance values (indicative values) of the sensors
fig. 66 Checking the mains-water sensor
fig. 67 Replacing the flow/return sensors
fig. 68 Boiler temperature sensor diagram
Boiler temperature sensor
(˚C)
R (Ω)
40
50
60
70
80
90
0
0
10
20
30
10,0005,000 15,000
NOTE
Fill the 800 Series and purge the system of
air.
Temperature
in °C
Resistance
in
Temperature
in °C
Resistance
in
0 29,490
5 23,462 55 3,271
10 18,787 60 2,760
15 15,136 65 2,339
20 12,268 70 1,990
25 10,000 75 1,700
30 8,197 80 1,458
35 6,754 85 1,255
40 5,594 90 1,084
45 4,656 95 1,940
50 3,893 100 1,817
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5.3.11 Replacing the mains-water sensor
Unplug cable connection from mains-water sensor.
Pull mains-water sensor out and push new unit in.
Plug in cable connection.
5.3.12 Checking the cables to the flow, return and safety
sensors, and to the burner thermostat
Check to ensure that all plug-in connections to the
sensors/burner thermostat and in the UBA are in
order. Note that an incorrectly-inserted plug can lead to
the generation of error messages. Start up the boiler by
pressing the “reset” button.
Set the mains switch to “0”.
Disconnect the system from the power supply.
Unplug the cable connection from the sensor/burner
thermostat.
Check the cable between the plug-in connection and
the
24-pin plug in the UBA with a continuity tester.
If the cables are in order, plug them in.
Connect system to mains power supply.
Set the mains switch to “I”.
fig. 69 Outside temperature sensor diagram
Outside temperature sensor
(˚C)
R (Ω)
0
5
10
15
20
25
-20
-15
-10
-5
50,00020,000 80,00040,00030,00010,000 60,000 70,000
fig. 70 Replacing the mains-water sensor
fig. 71 Checking the cable to the flow/return sensors
Rear side
of UBA
Flow sensor
Retur n sensor
Red wire slee ve
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fig. 72 Checking the cable to the safety sensor
fig. 73 Checking the cable to the burner thermostat
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5.3.13 Checking the burner thermostat
Unplug cable connection from burner thermostat.
Allow burner thermostat to cool down (activation tem-
perature 107 °C).
Check burner thermostat for throughput. If no
throughput is detected, the burner thermostat is defective.
If the burner thermostat is working correctly, plug it in
once more.
5.3.14 Replacing the burner thermostat
Pull cable lugs off.
Unscrew burner thermostat and screw in new unit.
Reconnect cable lugs and plug in once more.
5.3.15 Checking the hot surface ignitor
Disconnect the system from the power supply.
Unplug the hot surface ignitor.
Measure the resistance of the hot surface ignitor at
the plug. If the resistance is less than 200 , the hot
surface ignitor is in order.
Disconnect measuring device.
If the hot surface ignitor is working correctly, plug it in
once more.
Connect system to mains power supply.
fig. 74 Checking the burner thermostat
fig. 75 Replacing the burner thermostat
fig. 76 Checking the hot surface ignitor
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5.3.16 Replacing the hot surface ignitor
Disconnect the system from the power supply.
Disconnect the plug-in cable.
Loosen fixing screws and remove hot surface ignitor.
Fit new hot surface ignitor and retighten fixing
screws.
Plug in cable connection.
Connect system to mains power supply.
5.3.17 Checking the hose connection between the gas-air
injector and gas-valve assembly
Check hose connection for tightness and for signs of
possible blockages or damage.
Check that the hoses are correctly fitted to P1.
Hose connection:
P1 + , to T-piece gas-valve assembly.
fig. 77 Replacing the hot surface ignitor
fig. 78 Checking the hose connection between the gas-air
injector and gas-valve assembly (Honeywell gas
units)
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5.3.18 Check wiring connections on gas-valve assembly
Check that the plug-in cables are correctly attached
to the gas-valve assembly.
The plug-in cables should be connected as follows:
Blue plug-in lead: fig. 80, item 1 ;
White plug-in lead: fig. 80, item 2.
fig. 79 Checking the hose connection between the gas-air
injector and gas-valve assembly (SIT gas units)
fig. 80 Checking the wiring connections on the gas-valve
assembly (HONEYWELL assembly illustrated to
provide example)
1
2
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5.3.19 Checking the gas-burner assembly for correct
activation
Set the mains switch to “0”.
Remove a plug-in cable at the main gas valve and
connect a current-measuring device, at the same
point, with a measuring range of up to 1000 mA AC
(fig. 81, item 1).
Set the mains switch to “I”.
Unblock the 800 Series by pressing "reset" button,
and take current reading during start-up procedure.
Carry out the same measuring procedure at the
ignition-gas valve (fig. 81, item 2).
If the current reading at pos. 1 is approximately
210 mA and the reading at pos. 2 is about 450 mA,
the gas-valve activation system is in order.
Set the mains switch to “0”.
If the gas-valve assembly activation system is in or-
der, plug the cable in once more.
5.3.20 Replacing the gas valve assembly
Disconnect the system from the power supply.
Close the gas shutoff valve.
Remove all plug-in cables from the gas valve assem-
bly. Note order of cable terminals.
Loosen the screw-in adapter on the tube connector.
Remove the valve assembly and replace with a new
unit; attaching it to the screw-in connection adapter.
Connect all plug-in cables in the correct order.
With the system running, check for leaks at all joints
likely to have been affected by the fitting of replacement
parts.
fig. 81 Checking the gas valve assembly activation system
(HONEYWELL valve assembly shown as example)
1
2
fig. 82 Gas valve assembly replacement (HONEYWELL
valve assembly shown as example)
CAUTION!
Work on gas pipes and fittings must only be
carried out by a registered service provider.
NOTE
Carry out all initial start-up tasks as
indicated in the installation and servicing
instructions, and complete the
corresponding report form.
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5.3.21 Checking the wiring connection to the KIM
Disconnect the system from the power supply.
Check plugs and wiring connections to KIM
Connect system to mains power supply.
5.3.22 Checking the controller connections at the boiler
Set the mains switch to “0”.
Remove loop (non-conductive) from terminals 1
and 2.
Loosen cable at terminals 3 and 4.
Fit a link between terminals 1 and 2, 3 and 4.
Set the mains switch to “I” and press “reset”.
If the 800 Series goes into standby mode after start-
up
(display 0 H), the room-temperature control device is
defective.
Move mains power switch to “0”.
If the room-temperature control device is in order,
remove the bridging leads and attach the cable and
(non-conducting) link.
5.3.23 Replacing the room-temperature control device
Loosen all cables. Note order of cable terminals.
Attach cables, in the right order, to the new room-
temperature control device.
Carry out the corresponding adjustment settings on
the
room-temperature control device.
fig. 83 Checking the wiring connection to the KIM
fig. 84 Checking the controller connections at the boiler
NOTE
The system is delivered ready-fitted with a
non-conductive link between terminals
1 and 2.
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5.3.24 Checking the three-way valve for correct
activation
Set the mains switch to “0”.
Push in catch on regulating motor and remove bayo-
net connector by twisting anticlockwise (fig. 85).
Remove regulating motor.
Set the mains switch to “I” and press the “reset” but-
ton.
Once the 800 Series is in operation, open one of the
hot-water taps. If the regulating motor starts up
(check for movement of red adjusting lever), the activation system of the three-way valve is in order.
Shut the hot-water tap.
Set the mains switch to “0”.
If the activation system of the three-way valve is in or-
der, attach the regulating motor and lock into place
by twisting the bayonet connector.
5.3.25 Replacing the control valve
Close maintenance isolating valves and drain the
800 Series.
Remove the control valve with a spanner and fit a
new unit.
Fit regulating motor and lock into place by twisting
the bayonet connector.
Plug cable in.
fig. 85 Checking the three-way valve for correct activation
fig. 86 Replacing the valve core on the 800 –
24/24T25/29/43/60
NOTE
Open the maintenance isolating valves and
then fill the 800 Series and purge the
system of air.
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5.3.26 Replacing the three-way valve
Close maintenance isolating valves and drain the
800 Series.
Loosen all screw-in tube connectors.
Remove three-way valve and fit new unit.
Refit screw-in tube connectors.
Fit regulating motor and lock into place by twisting
the bayonet connector.
Plug cable in.
Open maintenance isolating valves.
5.3.27 Checking the condensation-water bypass
Check to ensure that the condensation-water bypass
is connected.
fig. 87 Replacing the three-way valve
Key to three-way valve:
A hot water
B heating
AB boiler feed line
A
AB
B
NOTE
Fill the 800 Series and purge the system of
air.
fig. 88 Function diagram of condensation-water bypass
NOTE
The device itself is fitted with an additional
condensation-water bypass (located on the
fume exhaust outlet).
Page 63
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Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
63
6 Appendix
6.1 Technical data
Size Unit
800 – 24 800 – 24T25
H/V
800 – 29 800 – 29T25
H/V
800–43 800–60
Type of gas category as per EN 437
Great Brittain
GB II
2H3P
20 mbar (natural gas H); 37 mbar (LPG) GB I2H 20 mbar
(natural gas H)
Rated thermal load
G20
[kW]
[Btu/h]
6.6 – 22.0
22,520 – 75,060
6.6–22.0
22,520 – 75,060
8.4 – 28.0
28,660 – 95,540
8.4 – 28.0
28,660 – 95,540
12.1–40.2
41,285 – 137,162
22.0–56.5
75,064 – 192,778
Rated heating capacity
Heating curve 75/60 C
Heating curve 40/30 C
[kW]
[Btu/h]
[kW]
[Btu/h]
6.4 – 21.4
21,840 – 73,020
7.0 – 23.4
23,880 – 79,840
6.4–21.4
21,840 – 73,020
7.0–23.4
23,880 – 79,840
8.2 – 27.3
27,980 – 93,150
8.8 – 29.9
30,030 – 102,020
8.2 – 27.3
27,980 – 93,150
8.8 – 29.9
30,030 – 102,020
11.8 – 39.3
40,260 – 134,090
12.9–42.9
44,015 – 146,375
21.4–55.1
73,016 – 188,000
23.7–60.0
80,865 – 204,720
Seasonal efficiency (SEDBUK) %
90.0 90.4 90.1 90.5 90.3 90.2
Boiler efficiency
Heating curve 75/60 C (max. capacity)
Heating curve 40/30 C (min. capacity)
[%]
[%]
97.3
107.0
97.3
107.0
97.5
107.1
97.5
107.1
97.8
107.0
97.6
107.1
Stand-by heat losses [%] 0.60 0.50 0.50 0.50 0.40 0.34
Central heating installation
Min. circulation water volume [
l
/h] 150 150 225 225 300 500
Heating water temperature [°C] 40 - 80 40 - 80 40 - 80 40 - 80 40 - 80 40 - 80
T at residual head of 200 mbar [K] approx. 15 approx. 18 approx. 18 approx. 18 approx. 22 approx. 20
Max. operating overpressure boiler [bar] 3 3 3 3 3 3
Volume heat exchanger heating
circuit [l]2.52.53.03.03.64.7
Pump over-run time
Position 1
Position 2
[min]
[h]
4
24
4
24
4
24
4
24
4
24
4
24
Hot water circuit combination boilers
Volume hot water reservoir [l] – 25 – 25 – –
Max. operating overpressure
hot water reservoir
[bar]–8–8––
Pump over-run time following
domestic hot water mode
[min] – 2 – 2 – –
Domestic hot water flow rate
at 60 °C [
l
/
min
]–6.0–8.0– –
Stand-by heat losses in hot
water mode in 24 hours at
WW (DHW)
temp
= 60 °C [kWh] – approx. 1.6 – approx. 1.6 – –
Page 64
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Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
64
Technical data - cont'd
Size Unit
800–24 800 – 24T25
H/V
800 – 29 800 – 29T25
H/V
800–43 800–60
Pipe connections
Gas [inch] R½ R½ R½ R½ R½ R¾
Flow & return [mm] Ø 28 Ø 28 Ø 28 Ø 28 Ø 28 Ø 28
Condensate water drain [mm] Ø32 Ø32 Ø32 Ø32 Ø32 Ø32
Flue gas values
Condensate water volume
natural gas H, 40/30 C
[l/h] 2.6 2.6 3.3 3.3 4.7 7.1
pH value condensate water approx. 4.1 approx. 4.1 approx. 4.1 approx. 4.1 approx. 4.1 approx. 4.1
Flue gas mass flow full load [g/s] 10.03 10.03 12.64 12.64 18.33 25.9
Flue gas temperature
Heating curve 40/30 °C
Heating curve 75/60 °C
[°C]
[°C]
45
65
45
65
45
65
45
65
45
65
45
65
CO2 full load,
natural gas G20
[%] 9.2 9.2 9.2 9.2 9.2 9.3
Standard emission factor CO [
mg
/
kWh
] <15 <15 <15 <15 <15 <15
Standard emission factor NO
x
[mg/
kWh
] <20 <20 <20 <20 <20 <20
Free feed pressure of fan [Pa] up to 140 up to 140 up to 140 up to 140 up to 140 up to 140
Gasrate G20 [m3/h] 2.33 2.33 2.96 2.96 4.25 5.98
Flue gas system
Type of flue gas system B23, B33, C13, C33, C43, C53, C
73
depending on room air and independent of room air
Diameter of flue gas system
dependent on room air
independent of room air
[mm]
[mm]
80
80/125
concentric
80
80/125
concentric
80
80/125
concentric
80
80/125
concentric
80
80/125
concentric
80
80/125
concentric
Electrical data
Mains connection voltage [V] 230 230 230 230 230 230
Type of enclosure IP40 (Bxx)
IP4X (C
xx
)
IP40 (Bxx)
IP4X (C
xx
)
IP40 (Bxx)
IP4X (C
xx
)
IP40 (Bxx)
IP4X (C
xx
)
IP40 (Bxx)
IP4X (C
xx
)
IP40 (Bxx)
IP4X (C
xx
)
Power consumption
full load
partial load
[W]
[W]
120
60
120
60
130
70
130
70
180
85
200
100
Boiler dimensions and weight V H V H
Height
Width
Depth
[mm]
[mm]
[mm]
685
560
431
1250
560
431
685
900
431
685
560
431
1250
560
431
685
900
431
685
900
431
685
900
431
Weight without casing [kg] 41 71 66 48 77 70 53 61
Weight casing [kg] 11 14 11 11 14 11 11 11
Page 65
Appendix 6
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
65
6.2 Residual pump lift for wall-hung gas boilers
The residual pump lift graphics show the amount of pump lift that remains for the heating system
1
600
500
400
300
200
100
0
0 200 400 600 800 1000 1200
Flow [l/h]
1400 1600 1800
2
800 – 24T25
1
2
T=20K
Residual pump lift [mbar]
maximum modulation
minimum modulation
(in heating mode only)
1
600
500
400
300
200
100
0
0 200 400 600 800 1000 1200
Flow [l/h]
Residual pump lift [mbar]
1400 1600 1800
2
800 – 24
12maximum modulation
minimum modulation
(in heating mode only)
T=20K
1
2
T=20K
0 200 400 600 800 1000 1200 1400 1600 1800
Flow [l/h]
Residual pump lift [mbar]
800 – 29T25
1
2
maximum modulation
minimum modulation
(in heating mode only)
600
500
400
300
200
100
0
1
600
500
400
300
200
100
0
0 200 400 600 800 1000 1200
Flow [l/h]
1400 1600 1800
2
800 – 29
1
2
T=20K
Residual pump lift [mbar]
maximum modulation
minimum modulation
(in heating mode only)
1
700
600
500
400
300
200
100
0
0 200 400 600 800 1000 1200
Flow [l/h]
Residual pump lift [mbar]
1400 1600 1800 2000 2200 2400 2600
2
800 – 60
1
2
maximum modulation
minimum modulation
(in heating mode only)
T=20K
T=20K
1
700
600
500
400
300
200
100
0
0 200 400 600 800 1000 1200
Flow [l/h]
Residual pump lift [mbar]
1400 1600 1800 2000
2
800 – 43
1
2
maximum modulation
minimum modulation
(in heating mode only)
T=20K
Page 66
Appendix6
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
66
6.3 Short list of spare parts
The following are parts commonly required due to
damage or expendability. Their failure or absence is
likely to affect safety or performance of this appliance.
For a pictorial representation of the part see the
respective position number on the exploded view picture
on page 8.
pos. description article no.
340 Gas/air manifold 73215
350
O-ring gas/air manifold to burner
(set of 5 pieces)
73440s
360
Gas injector, natural gas (G20)
incl. O-ring (800-24 only)
73224
360
Gas injector, natural gas (G20)
incl. O-ring (800-29 only)
73266
370
Air restrictor natural gas (G20)
(800-24 only)
73448
370
Air restrictor natural gas (G20)
(800-29 only)
73267
375
Connection tube, fan/burner
(800-24 only)
73477
380
Connection tube, fan/burner
(800-29 only)
73438
390 Air inlet pipe incl. gasket 73439
400
Support mounting bracket fan anti
vibration
73016
410 Fan 73320
420
Connection pipe gas valve/burner
(800-24 only)
73219
420
Connection pipe gas valve/burner
(800-29 only)
73207
430
Connection nipple ¾" x ½"
with O-ring
73209
440 Gas unit 73264
460 Gas inlet pipe ½" 76610
470 Control uba 7099845
480 Temp. pressure gauge 79021
490 Bracket for uba 73432
500 Power switch 38340
510 230V cable 7099204
520 Cable harness complete 75958
530 Supply pipe heat exchanger 73600
540 O-ring (set of 10 pieces) 79025s
550
Spring clip heat exchanger/supply
(set of 5 pieces)
73446s
560 Pressure relief valve 73197
570 Non return valve R ¼'' 75823
580 Pump 38622
590
Gasket for pump DN 44 x 2.5
(set of 10 pieces)
15022s
600
Pump power cable complete with
connector
73319
610 Ring (set of 5 pieces) 73480s
620
Nut for heat exchanger 1½''
(set of 5 pieces)
73481s
630 Swivel nut for pump 15020s
640 Return pipe 73122
650 Filling-, draining valve 38452
660 RTH converter 78079
pos. description article no.
10 Casing complete 7098751
20 Door 7098756
30 Casing clamp (2x left and 2x right) 73466
40 Casing seal 73454
50 Back panel 73030
60 Mounting bracket 75038
70 Seal lid for air vent 79090
80 Heat exchanger (800-29 only) 73020
80 Heat exchanger (800-24 only) 73031
90 Revision set for air vent 73116
100 Seal 73451
110 Sight glas complete with sealing rings 73412
120 Restriction plate (800-24 only) 73033
120 Restriction plate (800-29 only) 73019
130
Seal for condensate collector
(800-24 only)
73471
130
Seal for condensate collector
(800-29 only)
73458
140
Condensate collector incl. seal
(800-24 only)
73127
140
Condensate collector incl. seal
(800-29 only)
73125
150 Sensor complete with o-ring 38323
160 Mounting clip 73459
170
Seal for hot surface ignitor/ionisation
electrode. Set of 5 pieces
73461s
180 Hot surface ignitor 78105
190
Ionisation electrode with cable and
connector
38320
200 Safety sensor-ntc complete 73321
210 Flue gas collector 77450
220
Lip ring seal DN 80mm
(set of 10 pieces)
38419s
230 Condensate by-pass 75950
240 Syphon complete 75954
260 Safety valve pipe 73555
270 Seal set for syphon 73124
280 Burner housing (800-24 only) 73035
280 Burner housing (800-29 only) 73011
290
Burner thermostat 107 °C 36318
300 Burner seal (800-24 only) 73475
300 Burner seal (800-29 only) 73441
310 Gas/air distribution plate (800-24 only) 73217
310 Gas/air distribution plate (800-29 only) 73208
320 Secundairy gas/air distribution plate 73046
330
Burner plaque assembly (incl. gas/air
distribution plate) (800-24 only)
73018
330
Burner plaque assembly (incl. gas/air
distribution plate) (800-29 only)
73010
Page 67
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Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
67
7 Reports
7.1 Start-up report
Please check off the start-up tasks carried out and enter the corresponding readings, while making sure that you carefully follow
the instructions.
Initial start-up tasks Remarks or measurement readings
1.Note down gas characteristics:
Wobbe index
Operational heat value
––––––––––––––––––––
kWh/m³
––––––––––––––––––––
kWh/m³
2.Has a leak test been carried out?
(see chapter 2.1.5 on page 24)
3.Check combustion air/flue gas connection
4.Check the boiler equipment (change to another type of gas if
necessary)(see chapter 2.2.1 on page 26)
5.Carry out adjustment settings
(see chapter 2.2.2 on page 27)
6.Measure the gas supply pressure (flow pressure)
(see chapter 2.2.3 on page 29)
––––––––––––––––––––
mbar
7.Check and set the gas/air ratio
CO2-content: under full load
under partial load
(see chapter 2.2.4 on page 30)
––––––––––––––––––––
Pa
––––––––––––––––––––
%
––––––––––––––––––––
%
8.Check for leaks with system in operational condition
(see chapter 2.2.5 on page 31)
9.Record readings
Flow pressure
Exhaust-gas temperature, gross t
A
Air temperature tL
Flue temperature, net t
A
- tL
Carbon dioxide (CO
2
) or oxygen (O2) content
Exhaust-gas losses qA
Carbon monoxide content (CO), free from air
(see chapter 2.2.6 on page 32)
––––––––––––––––––––
Pa
––––––––––––––––––––
°C
––––––––––––––––––––
°C
––––––––––––––––––––
°C
––––––––––––––––––––
%
––––––––––––––––––––
%
––––––––––––––––––––
ppm
10.Testing the operation
Measure the ionisation current
(see chapter 2.2.7 on page 32)
––––––––––––––––––––-
µA
11.Fit the boiler casing
(see chapter 2.2.8 on page 33)
12.Instruct the user, hand over the documentation
(see chapter 2.2.9 on page 33)
13.Confirm commissioning (see Benchmark)
Confirmation of professional commissioning
(Company stamp, signature)
Page 68
Reports7
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
68
7.2 Inspection and service reports
The inspection and maintenance reports provide an overview of all the tasks and operations carried out.
See section 3: "Inspection" (page 34) and section 4: "Maintenance" (page 35).
Please check off the inspection and/or requirement-related maintenance tasks carried out and enter the corresponding readings.
Sign details of inspection and maintenance tasks, indicating date carried out.
Use only original replacement parts.
Inspection work Date: _____________ Date: _____________
1.Check the general condition of the installation
2.Visual and functional inspection of the installation
3.Check the gas and water transporting parts for:
internal leaks (see chapter 3.2 on page 34)
visible corrosion (see chapter 3.3 on page 34)
ageing
4.Check pollution of the burner, heat exchanger and siphon
(see chapter 4.1 on page 35)
5.Check the ionization electrode and incandesent firing electrode
(see chapter 4.1 on page 35)
6.Measure the ionization current
(see chapter 2.2.7 on page 32)
–––––––––––––––––––
µA
–––––––––––––––––––
µA
7.Measure the gas distribution pressure
(see chapter 2.2.3 on page 29)
–––––––––––––––––––
mbar
–––––––––––––––––––
mbar
8.Check the gas/air ratio
(see chapter 2.2.4 on page 30)
––––––––––––––––––––
Pa
––––––––––––––––––––
Pa
9.Gas leak test in operational condition
(see chapter 2.2.7 on page 32)
10.Measure the carbon monoxide content (CO), vacuum
(see chapter 2.2.6 on page 32)
––––––––––––––––––––
ppm
––––––––––––––––––––
ppm
11.Pressure-testing of heating system:
- Inlet pressure of expansion vessel
(see chapter 2.1.1 on page 23 + instructions supplied with the
vessel)
- filling pressure (see chapter 2.1.1 on page 23)
–––––––––––––––––––
mbar
–––––––––––––––––––
mbar
–––––––––––––––––––
mbar
–––––––––––––––––––
mbar
12.Check combustion air/flue gas pipes for correct functioning
and safety (see chapter 5.3.4 on page 49)
13.Check requirement-related adjustment settings of control device
(see documentation supplied with control unit)
14.Final check of inspection tasks, with record kept
of measurement readings and test results
15.Confirm servicing work
Confirmation of professional servicing work
(Company stamp, signature)
Page 69
Reports 7
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
69
Inspection and service reports - cont'd
Date: _____________ Date: _____________ Date: _____________ Date: _____________ Date: _____________
–––––––––––––––––––
µA
–––––––––––––––––––
µA
–––––––––––––––––––
µA
–––––––––––––––––––
µA
–––––––––––––––––––
µA
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––––
Pa
–––––––––––––––––––
Pa
–––––––––––––––––––
Pa
–––––––––––––––––––
Pa
–––––––––––––––––––
Pa
––––––––––––––––––
ppm
––––––––––––––––––
ppm
––––––––––––––––––
ppm
––––––––––––––––––
ppm
––––––––––––––––––
ppm
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
–––––––––––––––––
mbar
Page 70
Reports7
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
70
Requirement-related maintenance tasks Date: ___________ Date: ___________
1. Clean heat exchanger and burner
(see chapter 4.1 on page 35)
2. Check and adjust the gas-air ratio
CO
2
content: at full load
at partial load
(see chapter 2.2.4 on page 30)
______________Pa
______________ %
______________ %
_____________ Pa
______________ %
______________ %
3. Confirm servicing work:
confirmation of servicing carried out by a Gas Safe registered installer
(company stamp, signature)
Page 71
Reports 7
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
71
Date: ___________ Date: ___________ Date: ___________ Date: ___________ Date: ___________
______________ Pa
_______________ %
_______________ %
______________ Pa
_______________%
_______________%
______________ Pa
______________ %
______________ %
______________Pa
______________ %
______________ %
_____________ Pa
______________ %
______________ %
Page 72
Bosch Thermotechnik GmbH
Sophienstrasse 30-32
D-35576 Wetzlar
www.buderus.de
info@buderus.de
721.239A 0007
Buderus
Cotswold Way, Warndon, Worcester WR4 9SW,
Customer service: 0844 892 9700
Technical support: 0844 892 3004
Fax: 01905 753130
United Kingdom
www.buderus-commercial.co.uk
In the UK and IE, Buderus is a brand name of
Bosch Thermotechnology Ltd.
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