
U s e r m a n u a l
8G.52.70.00/12.10 Changes reserved.
A 2 0 0 S O V
Open vent heat only boiler

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Content
1. Introduction .................................................... 3
2. Safety ............................................................ 5
3. Boiler description ........................................... 6
4. Display and function keys .............................. 7
4.1 The Reset key ......................................... 7
4.2 Setting the heating water temperature .... 8
4.3 Requesting current data .......................... 8
5. Filling the heating system .............................. 9
6. Decommissioning the boiler .......................... 9
7. Error codes .................................................. 10
8. Maintenance ................................................ 10
9. Warranty ......................................................10
Important!
It is in your own interest that we should know that you have an ATAG
boiler. Please ll out the warranty card completely and send it back to
us. Then we can be fully at your service.

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These operating instructions describe the functioning and the operating of the ATAG A boilers.
This manual is for the end user. For installation
and servicing there is an installation & servicing
instructions manual for the installer.
Read this manual fully before operating the boiler.
In case of doubt or errors contact your installer.
ATAG Heating reserves the right to change the
specications and dimensions without prior notice.
Work on the boiler must be carried out by a competent person, (Ref: Gas Safe Register) using
correctly calibrated instruments with current test
certication.
When replacing parts use only ATAG Service parts.
Contact details for ATAG Heating UK Ltd can be
found on the back page of this manual.
1 Introduction

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The Benchmark Scheme
ATAG Heating UK Ltd is a licensed member of
the Benchmark Scheme which aims to improve
the standards of installation and commissioning
of domestic heating and hot water systems in the
UK and to encourage regular servicing to optimise
safety, efciency and performance.
Benchmark is managed and promoted by the
Heating and Hotwater Industry Council. For more
information visit www.centralheating.co.uk
Please ensure that the installer has fully completed the Benchmark Checklist on the inside back
pages of the installation instructions supplied with
the product and that you have signed it to say that
you have received a full and clear explanation of
its operation. The installer is legally required to
complete a commissioning checklist as a means
of complying with the appropriate Building Regulations (England and Wales).
All installations must be notied to Local Area
Building Control either directly or through a Competent Persons Scheme. A Building Regulations
Compliance Certicate will then be issued to the
customer who should, on receipt, write the Notication Number on the Benchmark Checklist.
This product should be serviced regularly to optimise its safety, efciency and performance. The
service engineer should complete the relevant
Service Record on the Benchmark Checklist after
each service.
The Benchmark Checklist may be required in the
event of any warranty work and as supporting
documentation relating to home improvements
in the optional documents section of the Home
Information Pack.“

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Work on the installation should only be carried out
by qualied personnel with calibrated equipment.
When replacing parts, only ATAG Service
components may be used.
If you smell gas:
- No naked ames! No smoking!
- Do not switch lights on or off or use other
electrical switches.
- Do not use the phone
- Close the gas mains
- Open windows and doors
- Warn the occupants and leave the building
- Only call the gas company or installer once you
are outside the building.
Corrosion protection
Do not use sprays, chlorine-containing cleaning
products, solvents, paints etc. in the vicinity of the
device or its air supply. These substances have
an adverse impact on the device and can lead to
corrosion that may result in failures.
Checking the heating water
Always use potable water for lling the installation.
Adding chemical agents such as frost and
corrosion inhibitors are only to be added by your
installer.
If in doubt, check with your installer or ATAG
Heating UK Ltd.
2 Safety

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The ATAG A is a closed, condensing and
modulating heating boiler which meets the
European standard (CE).
A declaration of conformity can be obtained from
the manufacturer.
The efficiency of the boiler is very high and
the radiation convection and standby losses
very low. The emission of noxious substances
is far below the fixed standards so the boiler is
SEDBUK Class A rated.
3 Boiler description
Example SEDBUK ClassA

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The boiler is equipped with a door at the front. After
opening the door you will nd a brief overview of
the meaning of all the keys and icons. These are
described below.
4 Display and function keys
4.1 Reset-key
The reset key restarts the boiler after a malfunction
has occurred.
In case of a failure the symbol is displayed
with a Cx xx code.
In other cases the Reset button has no function
and will not respond when operated.
See also chapter 7 'Errors'.
°C
(
OK )
( ESC)
+
-
-
i
R
+
Boiler operational
Error indication
Request for heating
Service mode or Blocking
Indicator for heating
Information key
Setting of boiler temperature
Reset key
n.a.

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Press + or - ;
The display will show the set value while ashing;
Press + or – to change the set value.
Each change becomes active directly.
Heating program OFF:
Press – until the lowest value is reached and then
press – again.
The display is showing -- and the upper is off.
Switching on works in reverse order.
Briey press the i-button or scroll button to obtain
the following values:
A0 = Supply water temperature
A1 = Return water temperature
A2 = Hot water temperature (n.a.)
A4 = Flue gas temperature
(Only if a ue gas sensor is connected)
A5 = Outside temperature (n.a.)
A6 = Water pressure
A9 = Rpms of fan
To return to the standard view press ESC.
4.2 Setting the heating water temperature
4.3 Requesting current data

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5 Filling the heating system
This boiler is part of an 'Open Vent' heating
system. The system is not pressurized, but is
lled automatically by a lling system in the loft.
If there is a problem with this system, please
contact your installer.
When the heating system is lled and after a
power interruption the boiler will be reset and starts
with a venting program. After the venting program
(display shows c1 05) of approx. 7 minutes has
ended, the boiler will be operational again.
In case of, for instance, a holiday:
Heating OFF:
Press the - key of the key until the lowest
value has been reached. Release the key and
press the – key once again. The display is showing
--. The program has thus disabled. The arrow to
the left is off.
In case of work on the heating installation:
Make sure no heat request occurs: set the room
thermostat to low. Pull the plug from the wall
socket. If the installation is being drained, you
have to take into account that part of the heating
water will remain in the boiler. Make sure that the
remaining heating water in the boiler cannot freeze
in case of frost.
6 Decommissioning the boiler

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In the event of a failure (this is indicated by a c
and number code on the display) you can try to
eliminate the failure by pressing the Reset key. If
the failure persists, please contact your installer
as soon as possible and tell him the number code.
There are also messages with a c and a number
code that constitute no failures. These messages
will cancel themselves over time. Operating the
reset button has no effect then, for example:
c1 05 venting program active (approx. 7 min.)
If leaks occur in the installation, please contact
your installer.
Venting program active
Conclude a maintenance agreement with your
installer in order to have the installation periodically
checked and adjusted.
The cover of the boiler consists of plastic parts,
which can be cleaned with a normal (nonaggressive) cleansing agent.
For the warranty conditions, see the Warranty
Card that has been delivered with the boiler.
7 Errors
8 Maintenance
9 Warranty

This renewed publication cancels all previous installation instructions. The company reserves the right to change the specifications and dimensions without prior notice.
ATAG Heating UK Ltd. • Unit 3 • Beaver Trade Park • Quarry Lane • Chichester • West Sussex • PO19 8NY
Phone: 01243 815 770 • Fax 01243 839 596 • E-mail: info@atagheating.co.uk • Internet: www.atagheating.co.uk
E. & O. E.