Atag i28C Release note

8G.51.84.01 / 03.19 Changes reserved. E.& O. E.
Installation & Servicing
Instructions
These instructions are to be retained by the user.
i24C
i28C
i36C
i40C
iC Economiser 27 Plus
iC Economiser 35 Plus
iC Economiser 39 Plus
Natural Gas Boilers
Boiler G.C No
i24C 47-310-36
i28C 47-310-37
i36C 47-310-38
i40C 47-310-39
iC Economiser 27 Plus 47-310-40
iC Economiser 35 Plus 47-310-41
iC Economiser 39 Plus 47-310-42
CE PIN 0063CQ3634

Installation & Servicing instructions ATAG iC-Range
2
Explanation of the Buttons
Selector Wheel Turn the wheel left or right to scroll
through available menu options
OK button Press to select/conrm an item
BACK button Press to go back one screen
RESET button Press to reset a fault code
Commissioning Press to enter into service mode which
button allows adjustment of high re/low re and
CO2settings (Do not use. For service
purposes only)

Installation & Servicing instructions ATAG iC-Range
3
Explanation of the Control Panel
When the boiler is turned on, the main screen (also called the home screen) appears in the screen.
1 DHW setpoint temperature
2 Current date and time
3 Heating supply setpoint
4 Outdoor temperature (if connected)
5 Visual illustration of current central heating temperature. Scale changes as the set temperature is
changed
6 Central heating status symbol. A box around the radiator symbol indicates central heating is in
operation
7 Current central heating system water pressure
8 Boiler status indicator, such as "Press OK to enter Menu", error messages and other status
information
9 DHW comfort or economy mode is active
10 DHW status symbol. A box around the tap symbol indicates DHW is in operation
11 Visual illustration of current hot water temperature. Scale changes as the set temperature is
changed
See chapter 12 for more information about button functions and read-out.
   








Installation & Servicing instructions ATAG iC-Range
4

personnel with calibrated equipment and appropriate tools.
Contents
1 Introduction......................................................................................................................................................5
2 Rules & Regulations (Symbols).......................................................................................................................6
3 Technical specications ...................................................................................................................................8
4 Dimensions ...................................................................................................................................................10
5 Delivery package ...........................................................................................................................................11
6 Boiler description ...........................................................................................................................................11
7 Boiler photo components list .........................................................................................................................12
8 Mounting boiler frame....................................................................................................................................13
8.1 Wall frame .........................................................................................................................................14
9 Connecting boiler...........................................................................................................................................15
9.1 Central heating system .....................................................................................................................15
9.2 Expansion vessel ..............................................................................................................................16
9.3 Water quality .....................................................................................................................................16
9.4 Heating systems with plastic pipes ...................................................................................................18
9.5 Gas connection in general ................................................................................................................18
9.5.1 Natural gas connection (NG).............................................................................................................18
9.5.2 Propane gas connection (LPG).........................................................................................................18
9.5.3 House pressure regulator..................................................................................................................19
9.5.4 Dimensioning of the low pressure gas line........................................................................................19
9.5.5 De-aerating the LPG tank .................................................................................................................19
9.6 Hot water supply ...............................................................................................................................20
9.7 Condensation drain pipe ...................................................................................................................20
9.8 Flue gas exhaust system ..................................................................................................................24
9.8.1 Flue terminal locations ......................................................................................................................25
9.8.2 Dimensioning of the ue gas and air intake duct ............................................................................28
9.9 Fitting the boiler onto the boiler frame..............................................................................................30
10 Electrical connection......................................................................................................................................32
10.1 External safety contact......................................................................................................................33
10.2 DHW sensor connection ...................................................................................................................33
10.3 OpenTherm BUS & ON / OFF connection ........................................................................................33
10.4 ATAG Zone connection .....................................................................................................................33
10.5 Solar inlet sensor connection ............................................................................................................33
10.6 ATAG Outside sensor........................................................................................................................33
10.7 230V Out (230V live output)..............................................................................................................33
10.8 230V In (230V live input)...................................................................................................................33
10.9 230V Control Block (230V live output) ..............................................................................................34
10.10 230V Control Block (SwL Switched live) ...........................................................................................34
10.11 External pump (230V live output)......................................................................................................34
10.12 Electrical diagram..............................................................................................................................35
11 Filling system.................................................................................................................................................36
11.1 Hot water supply ...............................................................................................................................37
12 Boiler controls................................................................................................................................................38
12.1 Change the Domestic Hot Water setpoint temperature.....................................................................39
12.2 Change the Central Heating setpoint temperature............................................................................40
12.3 Change the Domestic Hot Water Comfort Mode Setting...................................................................41
12.3.1 Always Active ....................................................................................................................................42
12.3.2 Time Based .......................................................................................................................................43
12.3.3 Disabled ............................................................................................................................................45
12.4 Change the language on the screen .................................................................................................46
12.5 Change the time and date.................................................................................................................47
12.6 Change Units of Measurement .........................................................................................................48
12.7 Boiler information ..............................................................................................................................49
12.8 Pump function ...................................................................................................................................51
13 Commissioning the boiler ..............................................................................................................................52
13.1 Checking the CO2..............................................................................................................................54
13.2 CO and combustion checks .............................................................................................................57
14 Parameter chapter.........................................................................................................................................59
14.1 Change the settings ..........................................................................................................................59
14.2 Parameter listing ...............................................................................................................................60
14.3 Weather compensation .....................................................................................................................62
14.3.1 Setting the weather compensation....................................................................................................63
15 Routine servicing ...........................................................................................................................................65
15.1 Interim Service ..................................................................................................................................65
15.2 Full Service .......................................................................................................................................66
15.3 Flow restrictor....................................................................................................................................70
15.4 Component replacement...................................................................................................................70
15.5 User's instructions.............................................................................................................................70
15.6 Warranty............................................................................................................................................70
16 Error codes and fault nding..........................................................................................................................71
16.1 Reset a Fault code ............................................................................................................................72
16.2 View Error code History ....................................................................................................................73
Annex A System water additives .....................................................................................................................74
Annex B Declaration of conformity ..................................................................................................................75
Annex C Short parts list ...................................................................................................................................76

Installation & Servicing instructions ATAG iC-Range
5
1 Introduction
These instructions describe the functioning, installation, use and primary maintenance of ATAG central heating
boilers for the United Kingdom.
These instructions are intended for the use of Gas Safe registered installers in connection with the
installation and putting into operation of ATAG boilers. It is advisable to read these instructions thoroughly,
well in advance of installation. Separate instructions for use are supplied with the boiler for users of ATAG
central heating boilers. ATAG is not liable for the consequences of mistakes or shortcomings which have
found their way into the installation instructions or user’s manual. Further, ATAG reserves the right to alter its
products without prior notication.
When delivering the boiler, give the customer clear instructions concerning its use; present the
customer with the user’s manual and warranty card.
Each boiler is tted with an identication plate. Consult the details on this plate to verify whether the boiler is
compliant with its intended location, e.g.: gas type, power source and exhaust classication.
On completion of the installation the installer or commissioning engineer must ll out and complete the
Benchmark Commissioning Checklist found on page 79 of this manual and hand this to the customer
for future record keeping. The Benchmark Service Record must also be completed by the service agent
following each service call, and return to the customer.

Installation & Servicing instructions ATAG iC-Range
6
2 Rules & Regulations (Symbols)
The following regulations apply to installation of ATAG central heating boilers:
Legislation and Regulations.
Gas Safety (Installation and Use). All gas appliances must by law, be installed by a competent person, eg.
Members of Gas Safe Register and in accordance with the current Gas Safety Regulation. Failure to install
appliance correctly could lead to prosecution.
All Gas Safe registered installers carry a Gas Safe ID card and have a registration number. You can call Gas
Safe Register directly on 0800 408 5577.
In addition to the above regulations this appliance must be installed in compliance with the current IEE
Regulations and Building Regulations. Regulations and bye laws of the Local Water Authority and the
Current Health and Safety Regulation.
The Benchmark Scheme
Benchmark places responsibilities on both manufacturers and installers. The
purpose is to ensure that customers are provided with the correct equipment
for their needs, that it is installed, commissioned and serviced in accordance
with the manufacturer’s instructions by competent persons and that it meets the
requirements of the appropriate Building Regulations. The Benchmark Checklist can be used to demonstrate
compliance with Building Regulations and should be provided to the customer for future reference.
Installers are required to carry out installation, commissioning and servicing work in accordance with the
Benchmark Code of Practice which is available from the Heating and Hotwater Industry Council who manage
and promote the Scheme.
Visit www.centralheating.co.uk for more information.
The current Electricity at Work Regulation must be complied with and also be in accordance with the relevant
and current editions of the British Standards.
The ATAG iC boiler is a certied appliance and must not be modied or installed in any way contrary to
this Installation Manual. Manufacturers instructions must not be taken, in any way, as overriding statutory
obligations.
The ATAG iC boiler is a central heating boiler with an integrated hot water function. The boiler must be
connected according to these instructions and all installation norms in respect of the part of the boiler to be
connected.
The appliance is not to be used by children or persons with reduced physical, sensory or mental
capabilities, or lack of experience and knowledge, unless they have been given supervision or
instruction.
Children being supervised not to play with the appliance.
Observe the following rules of safety:
- All work on the boiler must take place in a dry environment.
- ATAG boilers may never be in operation without their housing, except in connection with maintenance or
adjustments (see Chapter 15 and 16).
- Never allow electrical or electronic components to come into contact with water.
Carry out the following tasks in connection with maintenance, etc. to an already-installed boiler:
- Shut down all programs
- Close the gas isolation valve
- Shut down the 230V power supply
- Close the shut o󰀨 valve of the boiler’s cold water supply
See chapter 15 and 16 for further instructions.

Installation & Servicing instructions ATAG iC-Range
7
Take note of the following when maintenance or adjustments are needed:
- The boiler must be able to function during these activities; for this reason, the boiler’s 230V power supply,
gas pressure and water pressure must be maintained. Ensure that there is not a source of potential
danger during these activities.
Following maintenance or other activities; always check the installation of all parts through which

The following (safety) symbols may be encountered in these installation instructions and on the boiler
(packaging):
Boiler must be stored away from frost.
󰀩
transport.
Protect the boiler from weather conditions during transport and storage whilst still in its packaging.
If and how to clamp when using transport trucks with clamp equipment.
If and how to transport when using a rolling jack.
The whole packaging is made of recycled materials and can be recycled again.
Transport and place the boiler in its packaging in this position.
Do not to step on or stand on the package.
An assembly or dismantling must be carried out.
Pay extra attention in connection with a particular operation.
Useful tip or advice
Disposal of the product
This product should be handed in at a designated collection point, e.g. by handing it in at a duly authorized
reseller when purchasing a similar product, or at an authorized collection site for recycling products wich
contains electrical and electronic equipment (EEE) and batteries and accumulators. Because of the
potentially hazardous substances that usually accompany EEE, improper handling of this type of waste could
have a possible impact on the environment and human health.
Your cooperation in the proper disposal of this product will contribute to the e󰀨ective usage of natural
resources.
For more information on recycling this product, please contact your city o󰀩ce, local waste disposal facilities,
o󰀩cial service for chemical waste or landll site.

Installation & Servicing instructions ATAG iC-Range
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
ATAG iC-Series
Boiler type i24C i28C i36C i40C iC Economiser 27 Plus iC Economiser 35 Plus iC Economiser 39 Plus
Type heat exchanger iCon1 iCon1 iCon2 iCon2 iCon1 iCon2 iCon2
CE product identication number (PIN) 0063CQ3634
Country of destination UK
Qmin input min. CH & DHW (Hi) kW 4.5 4.5 6.2 6.2 4.5 6.2 6.2
Qn input nominal CH (Hi) kW 21.6 21.6 28.8 28.8 21.6 28.8 28.8
Qr adjusted input CH (Hi) kW 21.6 21.6 28.8 28.8 21.6 28.8 28.8
Qmin input min. CH & DHW (Hs) kW 5.0 5.0 6.9 6.9 5.0 6.9 6.9
Qn input nominal CH (Hs) kW 24.0 24.0 32.0 32.0 24.0 32.0 32.0
Qnw input nominal DHW (Hi) kW 24.0 27.3 35.4 37.9 28.3 36.3 37.9
Qnw input nominal DHW (Hs) kW 26.7 30.3 39.3 42.1 31.4 40.3 42.1
Pmin output min. CH (50/30°C) kW 5.0 5.0 6.9 6.9 5.0 6.9 6.9
Pn output nominal CH (50/30°C) kW 23.2 23.2 31.2 31.2 23.2 31.2 31.2
Pmin output min. CH (80/60°C) kW 4.4 4.4 6.1 6.1 4.4 6.1 6.1
Pn output nominal CH (80/60°C) kW 21.2 21.2 28.3 28.3 21.2 28.3 28.3
Pww output DHW kW 23.5 26.8 34.7 37.1 30.0 38.4 40.1
NOx class EN15502-1 6
O2(full load) % 4.7
CO2(full load) % 9.0
Appliance type B23, B33, C13, C33, C43, C53, C63, C83, C93
Flue gas temperature class T100
Max. ue resistance at Qnw/Qn Pa 130 153 191 143 151 140 148
Flue gas temperature CH (80/60°C full load) °C 59
Flue gas temperature CH (50/30°C full load) °C 34
Flue gas mass ow (full load DHW) g/s 10 11 14 15 11 14 15
Flue gas temperature CH (36/30°C low load) °C 30 30 30 30 30 30 30
Gas categories II2H3P
Gas pressure 2H / 3P mbar 20 / 37
Gas consumption max. G20 m3/hr 2.54 2.89 3.75 4.01 3.00 3.84 4.01
Current V/Hz ~ 230/50
Degree of protection acc. EN 60529 IPX4D (B22/B33 IPX0D)
Overrun time pump CH sec 60
Overrun time pump DHW sec 20
PMS water pressure CH min./max. bar 0.8 / 2.5
Flow temperature max. °C 80
Available pump height CH kPa 25 25 20 20 25 20 20
PMW water pressure DHW min./max. bar 0.5 / 8
DHW temperature setting (Tin=10°C) °C 60 60 60 60 60 60 60
Threshold DHW l/min 1.5 1.5 1.5 1.5 1.5 1.5 1.5
DHW ow (Tin=10°C, DT=35°C) l/min 10.1 11.5 14.9 16.2 12.6 16.1 17.0
DHW ow (Tin=10°C, DT=50°C) l/min 6.7 7.7 10.0 10.7 8.6 11.0 11.5
SAP Annual E󰀩ciency NG % 89.7 89.7 89.7 89.7 89.7 89.7 89.7
Weight boiler + jig (empty) kg 41 41 44 44 43 46 46
Content DHW part l 0.3 0.3 0.3 0.3 0.6 0.6 0.6

ATAG iC-Series
Boiler type i24C i28C i36C i40C iC Economiser 27 Plus iC Economiser 35 Plus iC Economiser 39 Plus
Type heat exchanger iCon1 iCon1 iCon2 iCon2 iCon1 iCon2 iCon2
O2(full load) % 5.1
CO2(full load) % 10.3
Restriction diameter/marking mm 4.10/41 4.10/41 4.60/46 4.60/46 4.10/41 4.60/46 4.60/46
Pre pressure mbar 37
Input CH (DHW) (Hi) kW 21.6 (23.9) 21.6 (27.3) 28.8 (35.4) 28.8 (37.9) 21.6 (28.4) 28.8 (36.4) 28.8 (38.3)
Gas consumption max. G31 kg/h 1.90 2.16 2.80 3.00 2.24 2.87 3.00
Gas consumption max. G31 m3/h 1.00 1.14 1.48 1.58 1.18 1.51 1.58
Modulation range CH (80/60°C) kW 8.3- 21.2 8.3- 21.2 19.1 - 28.3 19.1 - 28.3 8.3- 21.2 19.1 - 28.3 19.1 - 28.3
Modulation range CH (50/30°C) kW 9.0 - 23.2 9.0 - 23.2 20.8 - 31.2 20.8 - 31.2 9.0 - 23.2 20.8 - 31.2 20.8 - 31.2

Installation & Servicing instructions ATAG iC-Range
9

Brand ATAG
Boiler type i24C i28C i36C i40C iC Economiser 27 Plus iC Economiser 35 Plus iC Economiser 39 Plus
Condensing boiler yes yes yes yes yes yes yes
Combination heater yes yes yes yes yes yes yes
Declared load prole DHW XL XL XXL XXL XXL XXL XXL
Seasonal space heating energy e󰀩ciency class CH A A A A A A A
Water heating energy e󰀩ciency class DHW A A A A A A A
Pn Power output kW 21 21 28 28 21 28 28
QHE Annual energy consumption GJ 69 69 104 115 69 104 115
AEC Annual electricity consumption DHW kWh 49 51 52 52 57 52 52
AFC Annual fuel consumption DHW GJ 17 17 21 21 20 20 20
ηs Seasonal space heating energy e󰀩ciency CH % 94 94 94 94 94 94 94
ηWH Water heating energy e󰀩ciency DHW % 85 84 90 90 94 96 96
LWA Sound power level, indoors dB 46 46 48 48 46 48 48
P4 nominal output (80/60°C) kW 21.2 21.2 28.3 28.3 21.2 28.3 28.3
P1 30% of nominal output (36/30°C) kW 7.2 7.2 9.6 9.6 7.2 9.6 9.6
η4 e󰀩ciency at nominal input (GCV) % 88.3 88.3 88.6 88.6 88.3 88.6 88.6
η1 e󰀩ciency at 30% of the nominal input (GCV) % 99.4 99.4 99.5 99.5 99.4 99.5 99.5
elmax kW 0.074 0.074 0.074 0.074 0.074 0.074 0.074
elmin kW 0.021 0.021 0.032 0.032 0.021 0.032 0.032
PSB kW 0.004 0.004 0.004 0.004 0.004 0.004 0.004
Pstby heat loss kW 0.055 0.055 0.055 0.055 0.055 0.055 0.055
Qelec Daily electricity consumption DHW kWh 0.249 0.249 0.240 0.240 0.264 0.238 0.238
Qfuel Daily fuel consumption DHW kWh 22.700 22.961 27.315 27.315 25.649 25.122 25.122
Temperature Control Weathercompensator (outside sensor)
Class of temperature control II II II II II II II
Contribution of temperature control % 2 2 2 2 2 2 2
Package
Seasonal space heating energy e󰀩ciency of package % 96 96 96 96 96 96 96
CH Package Energy Label A A A A A A A
DHW Package Energy Label A A A A A A A
+
+
=

Installation & Servicing instructions ATAG iC-Range
10
4 Dimensions
CH Flow CH Return DHW Hot DHW Cold Gas
146
700 170
870
900 (boiler with economiser only)
30 (boiler with economiser only)
220225
60
125
220
315
380
440
343
A
B
B
ATAG iC-Series
i24C i28C i36C i40C iC Economiser 27 Plus iC Economiser 35 Plus iC Economiser 39 Plus
Flue gas / Air intake A/B mm 60/100
Gas connection mm 22
CH Flow connection mm 22
CH Return connection mm 22
Condensate drain connection mm 21.5
Cold water connection mm 15
DHW connection mm 15

Installation & Servicing instructions ATAG iC-Range
11
5 Delivery package
The delivery package of the boiler is composed as follows:
- Boiler frame;
- Boiler with cover;
- Automatic air vent (in boiler);
- Safety valve 3 bar (in boiler);
- Three way valve (in boiler);
- Automatic by-pass (in boiler);
- DHW ow restrictor (in boiler);
- Economiser (only economiser-versions)
- Expansion vessel 8 litre / 1 bar (in boiler frame);
- Isolation valves with drainpoint (CH 2x, 1x DHW cold)
- Gas isolating valve;
- Filling loop;
- Mains cold water lter;
- Fittings consisting of plugs and screws;
- Outside sensor;
- Drawing template;
- Installation instructions;
- User manual;
- Warranty Card.
The following components are not present in the boiler packaging as a standard and should be included in
the installation according to the requirements:
- Flue system;
- External controls.
6 Boiler description
The ATAG iC is a room sealed, condensing and modulating CH boiler equipped with an integrated hot water
supply.
The boiler is equipped with a compact stainless steel heat exchanger with smooth pipes. It is a well thought-
out principle using sustainable materials.
The boiler burns natural gas to supply heat (LPG conversion kits available). This heat is transferred in
the heat exchanger to the water in the CH installation. The rapid cooling o󰀨 of the ue gases causes
condensation. This results in a very high e󰀩ciency. The condensate that is formed, has no negative impact
on the heat exchanger and it's operation, and is removed through the internal siphon. This feature requires a
condensate drain pipe connected to the drain of the building.
The boiler is equipped with an intelligent control system. The boiler anticipates on the heat demand of the
heating installation or hot water demand. This will cause the boiler to tune its capacity to the installation. This
means that the boiler will function longer and at a low level.
If an outside sensor is connected, the control system is able to function, depending on the weather. This
means that the control system measures the outside temperature and the ow water temperature. On the
basis of this information the control system calculates optimum ow water temperature required for the
installation.
The boiler has been tested according to valid CE standards and has a CE certicate and >88% E󰀩cient
SEDBUK 2009.
Statement: No banned materials including asbestos, mercury, CFC's have or will not be included in
the product.

Installation & Servicing instructions ATAG iC-Range
12
7 Boiler photo components list
1 Heat exchanger
2 Ignition unit
3 Fan unit
4 Air supply damper
5 Gas valve
6 Automatic de-aerator
7 DHW plate heat exchanger
8 Control unit
9 Control panel
10 Three-way valve
11 Circulation pump
12 Filling loop
13 Flue gas exhaust
14 Combustion air supply
15 Boiler data plate
16 Expansion vessel
T1 Flow sensor
T2 Return sensor
T3 Hot water sensor
F1 DHW ow sensor
P1 Water pressure sensor
ATAG iC Figure 7.a
G Gas pipe
A Flow pipe CH
R Return pipe CH
C Condensation pipe
K Cold water pipe
W Hot water pipe
17 Safety valve
18 DHW Economiser
19 Siphon
20 Isolation valve ow CH
21 Isolation valve gas
22 Isolation valve cold water
23 Isolation valve return CH
24 Flue non return valve
T2
T3
2
1
5
F1
9
7
11
12
W CKG R
15
3
14
13
6
8
A
17
16
18
20 21 22 23
T1
P1
4
10
19
24

Installation & Servicing instructions ATAG iC-Range
13
8 Mounting boiler frame
Install the boiler in a boiler room in accordance to the actual local regulations BS5440-2:2009.
The installation location of the boiler has to be, and remain, frost-free. The boiler casing is splash water tight
(IPX4D) and is suitable to be installed in e.g. a bathroom.
It is NOT necessary to have a purpose 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 extremely low surface temperature of the boiler casing during operation. Therefore the requirements of
BS5440:2 may be disregarded.
The boiler can be mounted practically to any wall with the wall frame and the enclosed xing equipment. The
wall must be at and of su󰀩cient strength in order to be able to carry the boiler weight with its water content.
Above the boiler there must be at least 210 mm working space in order to be able to t a horizontal
concentric ue system to the rear (See chapter 9.8 for more ue options). Make sure there is su󰀩cient
service space around the boiler according gure 8.a. The location of the boiler can be determined by using
the template.
The wall frame allows the possibility to pre-t the complete heating and DHW system before tting the boiler.
Also the ue system can be prepared. Finally tting of the ue system is done after tting the boiler. See next
page for all options for connection the heating, DHW, condensate, ue and gas installation.
Before hanging the boiler to the boiler frame remove the front panel of the boiler rst. The front panel is also
the air cabinet and is attached to the boiler case with 2 fasteners (A and B) (see gure 8.a).

See chapter 9.8 for further procedure to t the boiler onto the boiler frame.
Service dimensions (in mm) Figure 8.a
*Economiser version only*Economiser version only
100
135*
2.5 2.5
400
Service space
Service space
210
AB

Installation & Servicing instructions ATAG iC-Range
14
8.1 Wall frame
- Position the boiler frame against the wall using the template and a level.
- Use the level for horizontal positioning and checking the vertical position.
- Drill 4x ø10mm holes, 60mm deep
- Press the nylon wall plug (ø10x55mm) in the holes
- Mount the boiler frame to wall with the 4 coach screws (ø8x60mm) using a 13mm wrench
The boiler frame allows pipe work to be installed behind the boiler.
Note that there are free spaces on the left and right of the expansion vessel. Do not guide pipe work
in front of the expansion vessel. The pipe work must be installed at least 10mm inside the front of the
frame.
ATAG i-Serie template and iC-Range boiler frame Figure 8.1.a
NO PIPING IN THIS AREA
TO AVOID OBSTRUCTIONS
44866920 C60708C
EXPANSION VESSEL HOSE PASSAGE
55 mm
= 395 mm =
= 380 mm =
65 mm
100 mm
635 mm
699 mm
= 440 mm =
65 mm40 mm65 mm 95 mm
440 225
355
700
2.5 mm
MINIMAL SIDE CLEARANCE
2.5 mm
MINIMAL SIDE CLEARANCE
210 mm
MINIMAL TOP CLEARANCE
FOR 60/100 FLUEGAS BEND
135 mm
MINIMAL BOTTOM CLEARANCE WITH ECONOMISER
100 mm
MINIMAL BOTTOM CLEARANCE
WITHOUT ECONOMISER
3
ELGNAEPIPSAGEULF
125 mm HOLE
FOR 60/100 FLUEGAS PIPE
120
BACK EXIT FLUE PIPE HEIGHT
FOR 60/100 FLUEGAS PIPE
121
SIDE EXIT FLUE PIPE HEIGHT
FOR 60/100 FLUEGAS PIPE
15 m : i24C/i28C iC Economiser 27 Plus i15R/i18R/i24R i15S/i18S/i24S
9 m : i36C/i40C i32R/i40R i32S/i40S
Elbow or
vertical adapter
225mm
121mm
8 m : iC Economiser 35 Plus/Economiser 39 Plus
330mm 435mm 540mm 645mm 749mm 854mm
2 m
4 m
6 m
8 m
10 m
12 m
14 m
3
Maximum straight length for Ø60/100:
173mm
1 m
= free space for piping

Installation & Servicing instructions ATAG iC-Range
15
9 Connecting boiler
The boiler has the following connection pipes;
- The central heating pipes.
The boiler is provided with isolation valves on the ow and return pipe to which the installation can be
connected by means of 22mm compression ttings;
- The gas pipe.
The boiler is provided with an isolation gas valve to which the gas line can be tted with 22mm
compression tting;
- The condensation drain pipe.
It consists of a 25mm exible plastic pipe. The drain pipe can be connected to this by means of an open
connection;
- The ue gas exhaust system and air supply system.
It consists of a concentric connection 60/100 mm.
- Cold and hot water pipes.
The boiler is provided with a isolation valve on the cold water inlet. The DHW installation can be
connected by means of 15mm compression ttings.
See following chapters for detailed information regarding each connection.

before connecting it to the boiler.
9.1 Central heating system
Connect the central heating system according to the current regulations.
The boiler pipes can be connected to the installation by means of 22mm compression ttings. For connecting
to thick-walled pipe (welded or tted), adapters should be used.
The boiler has a self-adjusting and self-protecting control system for the load. This involves checking the
temperature di󰀨erence between the ow and return water. Table 9.1.a shows the water displacement the
circulation pump can deliver for a particular installation resistance.
If the installation resistance is higher than the value stated, the control system will adjust the load until a
temperature di󰀨erence between ow and return water is reached that is acceptable for the control system.
When the temperature di󰀨erence still remains too high the boiler will switch itself o󰀨 and wait until the high
temperature di󰀨erential between the ow and return water has decreased again.
Pump type Grundfos UPM3 15-75
i24C i28C i36C i40C iC Economiser 27 Plus iC Economiser 35 Plus iC Economiser 39 Plus
Water ow rate l/min 15.2 15.2 20.3 20.3 15.2 20.3 20.3
l/h 912 912 1218 1218 912 1218 1218
Permissible installation resistance kPa 25 25 20 20 25 20 20
mbar 250 250 200 200 250 200 200
Installation resistance table 9.1.a
The control system will, if an unacceptable temperature di󰀨erence is detected, repeatedly try to establish a
water ow. If this does not succeed, the boiler will block itself.


heating return as close to the boiler as possible. ATAG Heating Technology Ltd recommend the use
of the:
 

Installation & Servicing instructions ATAG iC-Range
16
The boiler is not suitable for installations that are equiped with “open” expansion tanks.
Additives in the installation water are only permitted in consultation with the country distributor. See
chapter 9.3 for detailed information.
9.2 Expansion vessel
The iC boilers are featured with a built-in expansion vessel with a capacity of 8 litres and a pre-pressure
charge 1 bar. If the expansion vessel size is insu󰀩cient for the CH system, an additional expansion must be
installed. The additional expansion vessel should, together with the built-in expansion vessel, be sized to the
water content of the installation. The pre-pressure charge depends on the height of the installation above the
installed expansion vessel. See Table 9.2.a.
The (additional) expansion vessel should be connected as closely as possible in the return pipe near
the boiler.
Installation height above the expansion vessel pre-charge pressure of the expansion vessel
5m 0.5 bar
10m 1.0 bar
15m 1.5 bar
table 9.2.a
The pressure relief valve outlet is combined with the condensate outlet (see gure 9.9.e on page 31).
9.3 Water quality
Fill the installation with mains cold water.
In most cases, a heating system can be lled with water according to national standards for water and
treatment of this water is not necessary.
In order to avoid problems with the CH-installations, the quality of the lling water has to meet the
specications mentioned in table 9.3.a:
If the lling water does not meet the required specications, you are advised to treat the water to such an
extent that it does meet the required specications.


contact ATAG Heating Technology Ltd in advance, if things are not clear or you wish to discuss any
deviations. Without approval, the warranty becomes invalid.
Installation:
- The use of groundwater, demi-water and distilled water is prohibited. (on the next page you will nd an
explanation of these denitions)
- If the mains water quality meets the specications mentioned in table 9.3.a, you can start ushing the
installation before installing the device.
- Whilst ushing, corrosion products (magnetite), tting products, cutting oil and other undesirable products
have to be removed.
- Another possibility is to remove the pollution by installing a lter. The lter type has to t the type and
grain size of the pollution. ATAG Heating Technology Ltd recommends lter usage.
- In this case, the whole piping system should be taken into consideration.
- The CH-installation has to be properly vented before using the system. For that purpose, we refer to the
commissioning chapter.
- If a regular water top up is required (>5% on an annual basis), then there is a structural problem and
an installer has to solve the problem. Regularly adding fresh water to the system also adds additional
calcium and oxygen implying that magnetite and calcium residues can continue. The result may be
blockages and/or leakages.
- The use of anti-freeze and other additives requires periodical quality checks of the lling water in
accordance with the period laid down by the additives supplier.

Installation & Servicing instructions ATAG iC-Range
17
- Chemical additions are to be avoided and should only be used after ATAG Heating Technology Ltd has
approved their corresponding use.
- Should you wish to achieve the required water quality by using chemical additives, then this is your own
responsibility. The warranty on the product delivered by ATAG Heating Technology Ltd expires, if the
water quality does not meet ATAG Heating Technology's specications or the chemical additives have not
been approved by ATAG Heating Technology Ltd.
- On installation and during additions or changes at a later stage, ATAG Heating Technology Ltd
recommends to keep a record of the type of water used, its quality at the time, and if applicable, which
additives and quantities were added.
Parameter Value
Water type Potable water
Softened water
pH 6.0-8.5
Conductivity (at 20°C in µS/cm) Max. 2500
Iron (ppm) Max. 0.2
Hardness (°dH / ppm):
Installation volume/capacity
<20 l/kW
1-12 °dH / 17-214 ppm
Installation volume/capacity
>=20 l/kW
1-7 °dH / 17-125 ppm
Oxygen No oxygen di󰀨usion allowed during operation.
Max. 5% lling water addition annually
Corrosion inhibitors Refer to Additives Attachment
pH increasing or lowering agents Refer to Additives Attachment
Anti-freeze additives Refer to Additives Attachment
Other chemical additives Refer to Additives Attachment
Solid substances Not allowed
Residues of processing water not forming part of the
drinking water
Not allowed
table 9.3.a
Water quality in DHW facility
Parameter Value
Water type Potable water
pH 7.0-9.5
Conductivity (at 20°C in µS/cm) Max. 2500
Chloride (ppm) Max. 150
Iron (ppm) Max. 0.2
Hardness (°dH / ppm): 1-12 °dH / 17-214 ppm
Number of bacterial colonies at 22°C (number/ml). pr
EN ISO 6222
Max. 100
table 9.3.b
- When the amount of chloride is above the required specications mentioned above in table 9.3.b, in case
of the use of a combi boiler will void the warranty for DHW parts of the boiler.

Potable water: Tap water compliant with the European drinking water guideline:
98/83/EG dated 3 November 1998.
Softened water: Water with partly de-ionised calcium and magnesium.
Demi-water: Virtually completely demineralised water (very low conductivity)
Distilled water: Water no longer containing minerals.

Installation & Servicing instructions ATAG iC-Range
18
9.4 Heating systems with plastic pipes
When connecting or using an underoor heating system, designed with plastic pipes, or plastic pipes are
used elsewhere in the installation, one should ensure that the plastic pipes used comply with the DIN
4726/4729 standard. It is set out in this standard that the pipes may not have oxygen permeability higher
than 0.1 g/m³.d at 40°C. If the system does not comply with this DIN standard, the underoor heating
component will have to be separated from the central heating appliance by means of a plate exchanger.
No recourse can be made to the terms of the warranty in the event of failure to observe the

9.5 Gas connection in general
The local gas supplier should be consulted, at the installation planning stage, in order to establish the
availability of an adequate supply of gas. An existing service pipe must NOT be used without prior
consultation with the local gas supplier.

boiler is suitable for the gas kind on site.
For use with propane gas, the LPG conversion kit has to be installed, see separate conversion
instructions.
Make sure that the gas pipe work does not contain dirt, particularly with new pipes.
The complete installation MUST be tested for gas tightness and purged as described in the above
code.
The boiler connection is provided with an isolation valve with 22mm compression tting, into which the gas
line can be tted.
Ensure that the pipework from the meter to the appliance is of adequate size. Do not use pipes of a
smaller diameter than the boiler gas connection (22mm).
9.5.1 Natural gas connection (NG)
The gas supply must comply to the current Gas Safety, Installation & Use Regulations, in accordance with
BS.6891.
The nominal inlet working gas pressure measured at the appliance should be 21 mbar +/- 2 mbar for Nat
gas (G20). Allowing for the acceptable pressure loss of 1 mbar across the installation pipework, it can
be assumed that a minimum permitted operating pressure of 18 mbar will be delivered to the inlet of the
appliance. (Reference BS 6400-1 Clause 6.2 Pressure Absorption). When tested at the gas valve, the
pressure drop from the meter to the gas valve must not be more than 4 mbar.
9.5.2 Propane gas connection (LPG)
For use with propane gas, the LPG conversion kit has to be installed, see separate conversion instructions.
The LPG installation must comply to the current Gas Safety, Installation & Use Regulations, in accordance
with BS:6891
Installing of a LPG installation should only be done by a registered LPG installer.
The tank must be provided with a high pressure regulator with a minimum capacity of 24 kg/h to reduce
the tank pressure from 5 to 1.5 bar. The 1.5 bar high pressure gas line should have a minimum diameter of
15mm. In the high pressure gas line a house pressure regulator must be installed. When tested at the gas
valve, the pressure drop from the pressure regulator to the gas valve must not be more than 2.5 mbar.

Installation & Servicing instructions ATAG iC-Range
19
9.5.3 House pressure regulator
Each gas appliance which is connected to the propane installation must be provided with its own
house pressure regulator. The house pressure regulator is a third party delivery.
The house pressure regulator must have a minimum capacity of 10 kg/h / 37 mbar and a CE certication.
ATAG advices to install the house pressure regulator as close as possible to the boiler. When placing the
regulator inside, a discharge drain of ø6mm must be installed. The discharge drain must be directed outdoor.
In case of a discharge the gasses will go outside.
If tting the regulator outside the regulator should be protected against inuences of the weather. The (de-)
aeration must be positioned downwards (see gure 9.5.3.a).
ATAG advices to install measure points on all gas line parts to have the possibility to check for pressure loss.
Pre-pressure must be adjusted to 37 mbar by means of the house pressure regulator. The maximum
permitted closing pressure may be 5 mbar higher than the maximum pre-pressure.
A too high closing pressure in the low pressure gas line can be caused by a high resistance or jam in this gas
line. When the closing pressure keeps increasing the valve in the regulator is not closing correctly. In this
case the regulator should be replaced.
9.5.4 Dimensioning of the low pressure gas line
The gas line from the house pressure regulator to the boiler must have the dimensions according the table
below.
Pump type Grundfos UPM3 15-75
i24C i28C i36C i40C iC Economiser 27 Plus iC Economiser 35 Plus iC Economiser 39 Plus
Diameter gas line m m m m m m m
ø15mm 3 - - - - - -
ø22mm 30 18 18 18 18 18 18
ø28mm - 30 30 30 30 30 30
Dimensioning low pressure gas line table 9.5.4.a
9.5.5 De-aerating the LPG tank
When placing a new or revised LPG tank the tank must always be de-aerated.
ATAG advices to inform the gas supplier that a central heating boiler is connected to the LPG tank. For the
boiler it is absolutely necessary that the tank is free of air. When not the boiler will give ignition problems and
will not function.
ATAG advices to measure the content of O2. This value should be lower than 1.3%. Contact the gas
supplier in case of doubt.
example propane installation gure 9.5.3.a

Installation & Servicing instructions ATAG iC-Range
20
9.6 Hot water supply
Connection of the drinking water installation should be done according to the Water Supply (Water Fittings)
Regulations and Scottish Water Byelaws.
The ATAG iC boiler is tted with a stainless steel plate heat exchanger for producing domestic hot water. The
boiler does not have a hot water store and in case of a demand for hot water the boiler will heat the domestic
water owing through the plate heat exchanger up to 60°C (adjustable) instantaneous.
The water mains installation must comply with the Water Supply (Water Fittings) Regulations and Scottish
Water Byelaws. See also chapter 9.3.
In regions with a water hardness value higher than 200ppm (2.67 mmol/l), calcium deposits should
be removed from the plate heat exchanger on a regular basis. If problems occur when using sanitary
water with a chlorine content higher than 150 mg/l, no recourse can be made to the terms of the
warranty.
In order to prevent calcication ATAG recommends applying a water softener.
ATAG recommends the use of for instance AlphaPhos for cleaning plates exchangers.
The hardness of the water is variable in the United Kingdom. The water company can provide exact
information about this.
The domestic water installation can be connected to the boiler by means of 15mm compression ttings.
If the mains is tted with water meter, check valves or loose jumper stop cock, then a DHW expansion device
must be tted.
The boiler is provided with a DHW ow restrictor. The ow restrictor ensures that a quantity of water supplied
has a guaranteed temperature of 45°C (assuming a cold water temperature of 10°C) at its specied ow rate.
The amount of water is virtually una󰀨ected by the water pressure.
After installation, check the hot water ow rate with a fully opened hot water tap,
If required the ow restrictor can be removed. (See chapter 15.3)
9.7 Condensation drain pipe
The ATAG condensing boiler has the >88% E󰀩cient SEDBUK 2009 for high energy e󰀩ciency in heating and
domestic hot water. The ATAG wall hung gas red condensing boiler contain a siphonic condensate trap to
collect and realease condensate. The amount of condensate formed is determind by the type of boiler and
the water temperature produced by the boiler.
Condensate pipework.
Use plastic pipework of an internal diameter no less then 19mm ID (typically 22mm OD).
Routing of the pipework,
The condensate pipework must fall at least 45mm per metre away from the boiler, taking the shortest
practicle route to the termination point.
Support the pipe at least every 50 cm for near horizontal sections and 1 metre for vertical sections.
Wherever possible, the condensate pipework should be routed internally to prevent freezing. In order to
minimise the risk of freezing during prolonged very cold spells, one of the following methods of terminating
condensate drainage pipe should be adopted.
Internal pipework
Wherever possible, the condensate drainage pipe should be terminated at a suitable internal foul water
discharge point such as (a) an internal soil and vent stack or (b) an internal kitchen or bathroom waste pipe,
washing machine waste pipe etc. A suitable permanent connection to the foul waste pipe should be used.
Figures 9.7.1, 9.7.2(a), 9.7.2(b) show appropriate connection methods.
The possibility of waste pipes freezing downstream of the connection point should be considered when
determining a suitable connection point - e.g. a slightly longer pipe run to an internal soil stack may be
preferable to a shorter run connecting into a kitchen waste pipe discharging directly through the wall to an
external drain.
Where “gravity discharge” to an internal termination is not physically possible (e.g. the discharge point is
above the appliance location, or access is obstructed by a doorway), or where very long internal pipe runs
would be required to reach a suitable discharge point, the following measures may be adopted.