Atag Q 25S Release note

8G.51.40.00/03.06 Changesreserved.
Installation & Servicing
Instructions
These instructions to be retained by user.
Boiler G.C No
Q 25S 41-310-08
Q 38S 41-310-09
Q 51S 41-310-10
Q 60S 41-310-11
Q25C 47-310-10
Q38C 47-310-11
Q51C 47-310-12
CE PIN 0063BQ3021

Installation&ServicingInstructionsATAG
2
Q
Central heating on / off
Domestic hot water (DHW) on / off
Pump programme on / off
Reset key Unlocking the boiler
in case of error
Step key Selecting chapters
display
Explanations of symbols and signs on the Control Tower display.
1
2
No heat requirement
Ventilationphase
Ignition phase
Burner active on central heating
Burner active on hot water
Fan check
Burner off when room thermostat is demanding
Pump overrun phase for central heating
Pump overrun phase for hot water
Burner off because of to high flow water temperature
Automatic venting programme
3
4
5
6
7
8
9
A
Water pressure is to low (<1,0 bar),
flashingFILL willalternate withindication
of water pressure, boiler power of 50% is
possible. The installation needs to be
topped up.
Operation indication
(in the first display position by technical read out)
Mode key Selecting chapters
Water pressure is to high (>2,8 bar), if
HIGH indication remains continuously
visible,theboileristakenoutofoperation.
The installation pressure needs to be
decreased by draining water.
Water pressure is to low (<0,7 bar), FILL
indication remains continuously visible,
the boiler is taken out of operation. The
installation needs to be topped up.
0
From Good-read out to Technical read out (and vice versa):
- Press 5 sec. on the STEP key.

Installation&ServicingInstructionsATAG
3
Q
Content
1 Introduction ................................................................................................................................... 4
2 Regulations................................................................................................................................... 4
3 Scope of the supply ...................................................................................................................... 6
4 Descriptionoftheboiler................................................................................................................. 6
5 Mountingtheboiler ....................................................................................................................... 6
5.1 Dimensions........................................................................................................................ 7
6 Connectingtheboiler .................................................................................................................... 9
6.1 Centralheatingsystem ...................................................................................................... 9
6.2 Expansionvessel.............................................................................................................11
6.2.1 Expansionvesselmodule ................................................................................................ 12
6.3 Underfloorheatingsystem(plasticpipes)......................................................................... 13
6.4 Gasconnection ...............................................................................................................13
6.5 Hotwatersupply.............................................................................................................. 13
6.6 Condensationdrainpipe................................................................................................... 14
6.7 Flue gas exhaust system and air supply system ............................................................. 15
6.7.1 Dimensions of the flue gas and air intake duct ................................................................. 18
7 Externalhot watercylinders........................................................................................................ 19
8 Electricalconnection................................................................................................................... 20
9 Boilercontrols............................................................................................................................. 22
9.1 Explanation of the function keys ...................................................................................... 23
10 Fillingandventingtheboilerandinstallation................................................................................ 24
10.1 Hotwater supply .............................................................................................................. 24
11 Commissioningtheboiler............................................................................................................ 25
11.1 Centralheating system .................................................................................................... 25
11.2 Hotwater supply .............................................................................................................. 25
11.3 Adjustments .................................................................................................................... 26
11.4 Activatingfactory settings(greenkeyfunction) ................................................................ 28
12 Isolating theboiler...................................................................................................................... 29
13 Commissioning ........................................................................................................................... 29
13.1 Checkingforcontamination.............................................................................................. 29
13.2 Checkingof thezeropressurecontrol .............................................................................. 30
13.3 CheckingtheCO2............................................................................................................ 31
14 Maintenance ............................................................................................................................... 32
14.1 Frequencyofmaintenance ............................................................................................... 32
14.2 Maintenanceactivities...................................................................................................... 33
14.3 Warranty.......................................................................................................................... 33
15 Technicalspecifications .............................................................................................................. 34
16 Parts of the boiler........................................................................................................................ 35
17 Installationexamples .................................................................................................................. 36
17.1 Radiatorinstallationwithoutthermostaticradiatorvalves .................................................. 36
17.2 Radiatorinstallationwithunderfloorheatingzone ............................................................. 37
18 Errorindication............................................................................................................................ 38
19 Declarationofconformity............................................................................................................. 39
The appliance should only be installed by a Competent Gas Installer.
Work on the boiler must be carried out by a competent person, (Ref: Gas
Safety Installation, Use and Regulations ) using correctly calibrated
instrumentswithcurrent testcertification.

Installation&ServicingInstructionsATAG
4
Q
1 Introduction
These instructions describe the functioning, installation, use and primary maintenance
ofATAGcentralheatingunitsfortheUnitedKingdomandIreland.Wherenecessarythe
different regulations for each country are separately described.
These instructions are intended for the use by Corgi registered installers or registered
BordGaisinstallersinconnectionwiththeinstallationandputtingintooperationofATAG
units.Itisadvisabletoreadtheseinstructionsthoroughly,wellinadvanceofinstallation.
SeparateinstructionsforusearesuppliedwiththeunitforusersofATAGcentralheating
units.ATAG is not liablefor the consequences ofmistakes or shortcomingswhich have
found their way into the installation instructions or user’s manual. Further, ATAG
reserves the right to alter its products without prior notification.
When delivering the unit, give the customer clear instructions concerning its
use; present the customer with the user’s manual and card.
Each unit is fitted with an identification plate. Consult the details on this plate to verify
whether the unit is compliant with its intended location, e.g.: gas type, power source
and exhaust classification.
On completion of the installation the installer or commissioning engineer must fill out and
completetheBenchmarkcommissionsectionoftheboilerlogbookandhandtocustomer
orenduserforfuturerecordkeeping.TheBenchmarklogbookmustalsobefilledoutand
completedbytheservice agent following each servicecall,andreturnedto the customer.
AcopyoftheBenchmarkcommissioningcertificatemustbereturnedtoATAGHeatingUK
Ltd along with the warranty registration card to register the appliance for the standard
warranty benefits
Relevant Installation, Service and User manuals:
- ATAG Cascade Hydraulic cascade system
- ATAG Monopass Flue system individual
- ATAG PP Overpressure Flue system cascade
- ATAG BrainQ Digital room thermostat
- ATAG MadQ Cascade-/Zone controller
2 Regulations
The following regulations apply to installation of ATAG central heating units:
Legislation and Regulations.
Gas Safety (Installation and Use). All gas appliances must by law, be installed by a
competentperson,eg.MembersofCORGIandinaccordancewiththecurrentGasSafety
Regulation. Failure to install appliance correctly could lead to prosecution.
In addition to the above regulations this appliance must be installed in compliance with the
current IEE Regulations, the Building Standards (Scotland Consolidation) Regulations.
Regulations and bye laws of the Local Water Authority and the Current Health and Safety
Regulation.
Ireland:
- Irish standard 813
- Domestic gas installations

Installation&ServicingInstructionsATAG
5
Q
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.
TheATAG Qboilerisacertified applianceandmustnotbemodified orinstalledinany
way contrary to this Installation Manual.
Manufacturers instructions must not be taken in any way as overriding statutory
obligations.
The ATAG Q is a central heating unit with an optional integrated hot water function.
These units must be connected according to these instructions and all installation
norms in respect of the part of the unit to be connected.
Observe the following rules of safety:
- All work on the unit must take place in a dry environment.
- ATAGunitsmayneverbeinoperationwithouttheirhousing,exceptinconnection
with maintenance or adjustments (see Chapter 13 and 14).
- 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 unit:
- Shut down all programmes
- Close the gas tap
- Remove the plug from the wall socket
- Close the stop cock of the unit’s intake connection
Take note of the following when maintenance or adjustments are needed:
- The unit must be able to function during these activities; for this reason, the unit’s
supplyvoltage,gaspressureandwaterpressuremustbemaintained.Ensurethat
these is not a source of potential danger during these activities.
Following maintenance or other activities; always check the installation of all
parts through which gas flows (using leak-search spray).
Following maintenance or other activities, always replace the housing and
secure it with the screw behind the door at the front of the casing.
The following (safety) symbols may be encountered in these installation instructions
and on the unit:
This symbol indicates that the unit must be stored away from frost.
This symbol indicates that the packaging and/or contents can be damaged as
a result of insufficient care taken during transport.
This symbol indicates that, whilst still in its packaging, the unit must be
protected from weather conditions during transport and storage.
KEY-symbol. This symbol indicates that assembly or dismantling, must be
carried out.
ATTENTION symbol. This symbol indicates that extra attention must be paid
in connection with a particular operation.
Useful tip or advice

Installation&ServicingInstructionsATAG
6
Q
3 Scope of the supply
The boiler is supplied ready for use. The supply kit is composed as follows:
• Boiler with casing; • Template on the package wrapper;
• Automatic vent (inside the boiler); • Installation instructions
• Safety valve (inside the boiler); • Operating manual;
• Suspension bracket • Warranty card;
• Draining valve with T-piece; • Benchmark logbook.
• Fixing material consisting of plugs and
screws;
4 Description of the boiler
The ATAG Q boiler is a room sealed, condensing and modulating central heating
boiler, with or without an integrated hot water facility.
The boiler is provided with a compact stainless steel heat exchanger with smooth
tubes. A well thought out principal using durable materials.
The boiler burns gas for supplying warmth. The heat is transferred in the heat
exchangertothe water in the centralheatingsystem.Bycoolingdownthefluegasses
condensate is formed. This results in high efficiency. The condensate, which has no
effect on the heat exchanger and the function of the boiler, is drained through an
internal siphon.
The boiler is provided with an intelligent control system (CMS Control Management
System). The boiler anticipates the heat demand of the central heating system or the
hot water facility.
When an outside sensor is connected to the boiler works weather dependantly. This
meansthattheboilercontrolmeasurestheoutsidetemperatureandflowtemperature.
With this data the boiler calculates the optimal flow temperature for the installation.
Explanation of the type indication: ATAG Q 51C
Q = Type
51 = Nominal load in kW
C = Combi (S = Solo)
Theboilerhas been tested accordingtovalid CE* standards andhas a CE* certificate
andSEDBUKA-rating.
Statement:Nobannedmaterialsincludingasbestos,mercury,CFC'shavenotorwillnot
be included in the product.
Room sealed boiler
The boiler retreives its
combustion air to
outside then dis-
charges the flue
gasses to the outside.
Condensing
Retrieves heat from the
flue gasses. Water
condensates on the
heat exchanger.
Modulating
Higher or lower burning
according to the heat
demand.
Stainless
Super solid kind of
steel which keeps its
quality for life. It will not
rust or erode in con-
trast to composition
materials, like alumi-
nium.

Installation&ServicingInstructionsATAG
7
Q
5 Mounting the boiler
Theroom where the boiler will be placedmust always be frost free.
ItisNOTnecessarytohaveapurposeprovidedairventintheroomorinternalspacein
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
temperatureoftheboilercasingduringoperation.ThereforetherequirementsofBS6798,
Clause12,andBS5440:2may bedisregarded.
The boiler can be mounted practically to any wall with the suspension bracket and the
enclosedfixingequipment.Thewallmustbeflatandofsufficientstrengthinordertobeable
to carry the boiler weight with its water content.
Abovetheboiler there must beat least 250 mmworkingspace in order tobe able to fit
a coaxial flue system or a twin supply. On the left side of the boiler at least 50 mm and
on the right side 10 mm must be reserved to allow fitting or removing of casing. The
locationof theboilercanbedetermined byusingthetemplatelocated insidetheboiler
packaging.
Lift the boiler only by the boilers rear wall
Lifting and carrying precautions:
- Lift only a manageable weight, or ask for help.
- Whenliftingtheboiler,bendtheknees,andkeepthebackstraightandfeetapart.
- Do not lift and twist at the same time.
- Lift and carry the boiler close to the body.
- Wearprotectiveclothing and gloves to protect from anysharpedges.

Installation&ServicingInstructionsATAG
8
Q
Solo Combi
Boiler type Q25S
Q38S Q51S Q60S Q25C Q38C Q51C
mm mm mm mm
AHeight 680 680 680 680
BWidth 500 660 840 1000
CDepth 385 385 385 385
D Left side / flue gas exhaust 335 495 335 495
ECentre to centre / flue gas exhaust
and supply 120 120 120 120
F back / flue gas exhaust 270 270 270 270
GLeft side / gas pipe 65 65 65 65
H Left side / flow pipe 185 185 185 185
JLeft side / return pipe 285 445 285 445
K Left side / condensate pipe 370 530 370 530
LLeft side / expansion pipe 430 430 590
M Left side / return pipe DHW 475
NLeft side / cold water pipe 725 885
O Left side / hot water pipe 795 955
PPipe length of g* 18 18 18 18
Q Pipe length of c* 50 50 50 50
RPipe length of f, r, e, d,k and w* 60 60 60 60
S Back / Centre of pipe c* 25 25 25 25
TBack / Centre of pipe g* 40 40 40 40
U Back / Centre of pipe f, r, e, d, k and w* 50 50 50 50
5.1 Dimensions
dimensions talel 1
dimensions (in mm) figure 1
wall
C
E
F
A
U
T
S
wall
B
MN
PQR
B
wall
D
HJK
1050
G
L
HJK
G
D
ceiling
Minimal 250mm
L
P

Installation&ServicingInstructionsATAG
9
Q
Solo Combi
Boiler type Q25S
Q38S Q51S Q60S Q25C Q38C Q51C
Combustion air supply / flue gas
system mm 80/125 80/125 80/125 80/125
Gas pipe - g ½" female ¾" female ½" female ¾" female
Flow pipe - f mm 28 35 28 35
Return pipe - r mm 28 35 28 35
Condensate pipe - c mm 24 24 24 24
Expansion pipe - e mm 22 22
Cold water pipe - k mm 15 15
Hot water pipe - w mm 15 15
Return pipe DHW - d mm 28
connection diameters table 2
boiler connections figure 2
g a r c e k wg a r c

Installation&ServicingInstructionsATAG
10
Q
6 Connecting the boiler
Theboilerhasthefollowingconnectionpipes;
- Thecentralheatingpipes.
These can be connected to the installation by means of compression fittings;
- Thegaspipe.
It is provided with a female thread into which the tail piece of the gas valve can be
screwed;
- Thecondensationdrainpipe.
It consists of an oval 24 mm plastic pipe. The drain pipe can be connected to this
bymeansofanopenconnection.Iftheopenconnectionisfittedinadifferentlocation,
then the pipe can be lengthened by means of a 32 mm PVC sleeve;
- The flue gas exhaust system and air supply system.
It consists of a concentric connection 80/125 mm.
-Coldandhotwaterpipes.
Only Combi boilers: These consist of 15 mm copper pipe and can be connected
to the installation by means of compression fittings.
It is recommended that isolation valves are fitted to all heating and hot water
connections to facilitate ease of future maintenance.
It is advisable to spray-clean all of the unit’s connecting pipes and/or to
spray-clean/blow-clean the installation before connecting it to the unit.
6.1 Central heating system
Connect the central heating system according to the actual regulations.
Theboilerpipescanbeconnectedtotheinstallationbymeansofcompressionfittings.
Reducers should be used for connecting to thick-walled pipe (welded or threaded).
When removing the plastic sealing caps from the pipes, contaminated testing
water may be released.
Theboilerhasaself-adjustingandself-protectingcontrolsystemfortheloadandthepump
capacity. By this means the temperature difference between the flow and return water is
checked.Table3showsthewaterdisplacementwhichsuppliesthecirculationpumpat
certain installation resistance.
A low velocity header must be connected to the Q51C, Q51S and Q60S to
prevent flow problems over the boiler.
ATAGsuppliestheAA1OV09ULowvelocityheaderfor1boiler.Thiscanbeconnected
directly under the boiler on the flow and return pipe.
Boiler type pump type water flow rate permissible installation
resistance
UPER l/min l/h kPa mbar
Combi
Q25C 20-60 16,2 972 29 290
Q38C 20-70 24,6 1478 20 200
Q51C 20-70 30,1 1803
Solo
Q25S 20-60 9,7 583 47 470
Q25S 20-60 16,2 972 32 320
Q38S 20-70 24,6 1478 22 220
Q51S 20-7030,11803
Q60S 20-70 38,9 2333
Installation resistance table 3

Installation&ServicingInstructionsATAG
11
Q
If the installation resistance is higher than the stated value the pump will rotate at
maximumpumpcapacityandtheloadwillbeadjusteduntilanacceptabletemperature
difference between flow and return water has been obtained. If, after this, the
temperature difference remains to much then the boiler will switch itself off and wait
until an acceptable temperature has arisen.
If an unacceptable temperature is detected, then the control will repeatedly try to
achieve water flow, and if this does not work then the boiler will switch off.
Ifthecapacityoftheboilerpumpisinsufficient,anextraexternalpumpcanbeinstalled
incombinationwithalowvelocityheaderinserieswiththeboiler.Theelectricalsideof
thisexternalcirculationpumpcanbeconnectedintheControlTower,bywhichmeans
this pump switches at the same times as the boiler pump.
Themaximumabsorbedcurrentconsumptionoftheexternalcirculationpumpmaybe
230 W (1 Amp). The extra external pump must be selected according the installation
resistance and required flow.
pump index lines graph 1
Q(m³/h)
100% UPER 20-70
Q25C, Q38C
Q25S,Q38S
100%
UPER 20-60
H(m)
25% UPER 20-60
25% UPER 20-70
Asstandardtheboilerisprovidedwithawaterfilterinthereturnpipeoftheboiler.With
this, possible contamination of the central heating water is prevented from ending up
in the boiler. The boiler is also provided with an internal safety valve set at 3 bar. This
is connected to the waste discharge together with the condensation discharge.
If all, or a large part of the radiators are provided with thermostatic radiator valves it is
advisabletouseapressuredifferencecontrol(bypass)inordertopreventflowproblems
in the installation.
The boiler is designed to be used on sealed system only.
Additives in the installation water are only permitted in consultation with the
country distributor.
When using more than one boiler in an installation please refer to the cascade
installation instructions.
external installation pump
with low velocity header
figure 3

Installation&ServicingInstructionsATAG
12
Q
6.2 Expansion vessel
Thecentralheatingsystemmustbeprovidedwithanexpansionvessel.Theexpansion
vesselwhichisusedshouldbegearedtothewatercontentoftheinstallation.Thepre-
charge pressure depends on the installation height above the mounted expansion
vessel. See table 4.
All Combi boilers are provided with an expansion vessel connection. This pipe is
connected with the three way valve and boiler pump. This prevent the expanding
water,duringhotwaterproduction,isbeingclosedofffromtheexpansionvessel,when
the thermostatic radiator valves are fully closed. A second expansion vessel in the
installation is not a problem.
The Solo boilers Q15S, Q25S and Q38S are provided with an expansion vessel
connection. When this boiler is combined with a cylinder, the expansion vessel
connectionisincludedintheinternalpipingofthecylindercircuit,towhichtheexpansion
vessel can be connected.
In connection with correct functioning of the boiler it is necessary for the
expansion vessel to be connected to the expansion vessel pipe of the boiler.
The Solo boilers Q51S and Q60S are not provided with an expansion vessel
connection. When one of these Solo boilers is combined with a cylinder then one has
to take into account that the expansion vessel should be connected between the three-
way valve and the boiler circulation pump.
choice of expansion vessel table 4
installation height above
the expansion vessel pre-charge pressure of the expansion vessel
5 m 0,5 bar
10 m 1,0 bar
15 m 1,5 bar

Installation&ServicingInstructionsATAG
13
Q
side view of the module with boiler (dimensions in mm) figure 5
540
wall
155 385
front view of the module with boiler (dimensions in mm) figure 6
660
105
6.2 Expansionvesselmodule
TheATAGQ25SandQ38Sboilerscanbeprovidedwithanexpansionvesselmodule.
By this means the external expansion vessel is not required. This expansion vessel
moduleisplacedbehindtheATAGQboiler,bywhichmeanstheexpansionvesselisnot
noticeable.Thecontentofthetwoexpansionvesselsis20litres.Thepre-chargepressure
is 1 bar.
Theexpansionvesselmodulecanbesuppliedwiththenecessarypipestoconnectwith
the ATAG Q boiler. The connecting pipes for the installation correspond with those of
the boiler and have the same centre-to-centre distance to the wall.
Whencheckingtheexpansionvesselstheseareaccessibleviatheleft,rightandupper
sides. From these sides the tanks are also removable and the boiler does not have to
be dismantled.
The space which is required for mounting the expansion vessel module corresponds
with the required space for mounting an ATAG Q boiler. They included template and
mounting strip for the boiler which can be used for the expansion vessel module. The
boiler is fitted on to this after the expansion vessel module has been mounted. The
necessary mounting strip for the boiler is present on the module.
Article numbers:
- the expansion vessel module without pipe connections AA1EM09U
- pipe connections for expansion vessel module AA1LE04U
480
expansion vessel module
figure 4

Installation&ServicingInstructionsATAG
14
Q
6.3 6.3 Underfloorheatingsystem(plasticpipes)
When connecting or using an underfloor heating system, designed with plastic pipes,
orplasticpipesareusedelsewhereintheinstallation,oneshouldensurethattheplastic
pipes used comply with the DIN 4726/4729 standard. It is set out in this standard that
thepipesmaynothaveoxygenpermeabilityhigherthan0.1g/m³.dat40°C.Ifthesystem
doesnotcomplywiththisDINstandard,theunderfloorheatingcomponentwillhaveto
beseparatedfrom the central heating appliancebymeans of a plateexchanger.
No recourse can be made to the terms of the warranty in the event of failure
to observe the regulations pertaining to plastic underfloor heating pipes.
6.4 Gas connection
The appliance pipe is fitted with an internal thread, into which the tail piece of the gas
tap can be screwed.
United Kingdom:
The gas supply must comply to the current Gas Safety Regulations.
Ireland:
- Irish standard 813
- Domestic gas installations
Theconnection to the appliancemust include asuitable method of disconnection and a
gascontrol cock must be installed adjacent to the appliance for isolation purposes. The
nominalinletworkinggaspressuremeasuredattheapplianceshouldbe20mbarforNat
gas (G20).
Make sure that the gas pipe work does not contain dirt, particularly with new
pipes.
When the boiler has to be converted from natural gas to LPG, ATAG provides special
kits for this purpose. Special instructions are supplied with the kit.
Always check the installation of all of the parts through which gas flows
(using leak-search spray)
6.5 Hot water supply
Connection of the drinking water installation should be done according to the national
water laws.
Thesanitarywaterpipescanbeconnectedtotheinstallationbymeansofcompression
fittings. The cold water inlet on the Combi boilers must be provided with the following
(counted in the water flow direction):
Dosing valve (supplied), Safety group, Expansion vessel 6bar (potable water, blue).
A dosing valve must be fitted in the cold water pipe. The dosing valve ensures that a
quantity of water is supplied which has a guaranteed outlet temperature of 60°C
(assuming a cold water temperature of 10°C). The quantity of water is virtually
unaffected by the water pressure.
Withawaterpressurelowerthan1.5baritisadvisabletoremovetheinsidemechanism
of the dosing valve.

Installation&ServicingInstructionsATAG
15
Q
6.6 Condensationdrainpipe
ATAG boilers produce condensate. This condensate must be drained otherwise the
boiler will not function.
Thecollectingcondensationdrainpipeshouldbeconnectedtothedrainbymeansofanopen
connection. By this means the possibility of drain gases ending up in the boiler is
prevented. The drain connection should have a minimum diameter of 32mm.
Connect the condensation drain pipe according to the actual regulations.
The following components are connected to the collective condensation drain pipe:
- Condensation discharge;
- Safety valve;
Draining of the condensation water to the external rain guttering is not
permitted in view of the danger of freezing.
Before putting the boiler into operation fill the siphon with 300 ml of water.
The condensate pipe must be run using suitable corrosion resistant materials (eg.
plastic).

Installation&ServicingInstructionsATAG
16
Q
6.7Fluegasexhaustsystemandairsupplysystem
The flue gas exhaust system and air supply system consists of:
- Flue gas pipe;
- Air supply pipe;
- Rooforwallterminal.
The flue gas exhaust system and air supply system must comply with:
United Kingdom:
The flue gas outlet and air supply installation must comply with the current regulation
requirements. IG UP 10 and BS 715.
Ireland:
- Irish standard is 813 section 9.10.1
Open boiler
Room sealed system
SS
PP
SS
PP
PP
SS
PP
Open boiler en roomsealed system figure 8
PP
PP/MW PP/MW PP/MW
All flue gas parts, which are outside the fire
resistant cover, need to be in stainless steel.
Boiler Class C
Permitted only
when the air
intake and the flue gas
outlet are in the same
pressure area.
BoilerClass B
Free exhaust area
Air filter

Installation&ServicingInstructionsATAG
17
Q
The appliance connection diameter is 80/125 mm, to which the flue gas outlet and air
supply system can be fitted, with or without elbow pieces. The maximum permissible
pipe length is set out in Table 5.
Itisalsopossibletouseaparallelpipeconnectionof2x80mm.Inthiscaseaseperate
cover125mmshouldbeordered.Art.nr.S4323410.
We advise to build a simple flue gas system and air supply system out of table 6. For
furtherinformationabouttheavailablecomponentsofthefluegasandairsupplysystem
we recommend you consult the Monopass Flue systems.
The ATAG flue gas system is meant and designed solely the use on ATAG central
heatingboilers adjusted for Nat gas or LPG.The maximum flue gas temperatures are
below 70°C (full load 80/60°C)
Theproperoperationcan be influenced harmfully by changes of or adjustments to the
correct set up.
Possible warranty claims will not be honoured if incorrect changes result in non
compliance with the installation manual or local rules and regulations.
The flue gas systems described in this document are solely suited for ATAG central
heatingboilersoftheATAGboilerrange. ForthispurposetheCECertificatehasbeen
supplementedundertheGastecnr:0063BQ3021,0063AS3538and0063AU3110.
The flue gas system should be built up using only ATAG program products.
CombinationswithotherbrandsorsystemsarewithoutwrittenpermissionfromATAG
Heating is not permitted.
Horizontal flue system should always be installed sloping towards the boiler, in order
to avoid condensate lying in the flue system.
The minimum gradient is 50mm/Mtr. With the condensate running back to the boiler the
risk of ice forming at the terminal is reduced.
Theterminalshouldbelocatedwheredispersalofcombustionproductsisnotimpeded
and with due regard for the damage or discolouration that might occur to building
products in the vicinity (see fig 9).
terminal position for fan assisted boiler minimum
distance
Adirectly below an open window or other opening
(e.g. air brick) mm 300
B below gutters, soil pipes or drain pipes mm 75
Cbelow eaves mm 200
D below balconies or car port roof mm 200
Efrom vertical drain pipes and soil pipes mm 75
F from internal or external corners mm 300
Gabove ground or below balcony level mm 300
H from a surface facing a terminal mm 600
Ifrom a terminal facing a terminal mm 1200
Jfrom an opening in the car port (e.g. door
window) into dwelling mm 1200
Kvertically from a terminal on the same wall mm 1500
L horizontally from a terminal on the same wall mm 300
Mhorizontally from a vertical terminal to a wall mm 300
Dimensions table 6
figure 9

Installation&ServicingInstructionsATAG
18
Q
Incertainweatherconditionscondensationmayalsoaccumulateontheoutsideofthe
airinletpipe.Suchconditionsmustbeconsideredandwherenecessaryinsulationofthe
inletpipemaybe required.
Incoldand/orhumidweatherwatervapourmaycondenseonleavingtheflueterminal.
The effect of such ‘plumeing’ must be considered.
The terminal must not be located in a place where it is likely to cause a nuisance.
Forprotectionofcombustibles,refertoIS813section9.10.1.wheretheterminalisless
than2m(6.6ft)aboveapavementorplatformtowhichpeoplehaveaccess(including)any
balcony or flat roof the terminal must be protected by a guard of durable material.
A suitable guard is available from the country distributor.
Where a terminal is fitted below a window which is hinged at the top, and
where the hinge axis is horizontal, and the window opens outwards, the
terminal shall be 1m below the bottom of the window opening.
If the boiler is to be located under stairs, a smoke alarm meeting the
requirements of I.S. 409 or equivalent must be fitted.
The flue must be terminated in a place not likely to cause a nuisance.
Forhorizontalsections,theoutletsystemshouldalwaysbefittedonanincline(50mm/
m) sloping down towards the appliance so that no condensation water is able to
accumulate in the outlet system. The chances of icicles forming on the roof outlet is
minimisedbycausingthecondensationwatertorunbacktowardstheappliance.Inthe
case of horizontal outlets the inlet system should be fitted on an incline sloping down
towards the outside to prevent rainwater from coming in.
The appliance produces a white wisp of condensation (plumeing). This wisp of
condensationisharmless,but can be unattractive, particularlyinthecaseof outlets in
outsidewalls.
Atthistimethereare2differentwaysofconnectingthefluegas/airintakesystem.The
fluegasductforthe60/100,80/125and100/150arepushfitconnections,seefigure10.
The air intake for the 60/100 is a clamp ring connection.
Thesetwotypesarenotinterchangeable.
Cutting the pipe goes as follows:
- Take out the inner tube by turning it until it releases from its security position;
- Cut just as much from the air intake part as from the flue gas part;
- Take off the burrs from the cutting edge to prevent cutting the seals;
- Click the pipes back together again.
Use special grease to simplify the fitting
Whenmountingthefluegassystem,payattentiontotheflowdirection.Anarrowonthe
productpointsthisout.Itisnotpermittedtomountasystemupsidedownandwilllead
to complaints.
Dismantlement and shorten pipes figure 11

Installation&ServicingInstructionsATAG
19
Q
6.7.1 Dimensioningofthefluegasandairintakeduct
Thefluediameterisdeterminedbythetotallengthoftherun,includingfortheconnection
pipe,elbowsfittingsandterminalcoversetcandthetypeandnumberofboilersinstalled
into the system.
Anundersizedfluepipecanleadtodisorders.Lookattable1forthechoiceofthesystem
and the correct diameter. The table below shows the maximum flue lengths with the
different boiler outputs. A longer flue gas length can be achieved by increasing the
diameterto ø100mm.
Explanation table 1:
Two pipe flue gas system: maximum noted length = distance between boiler and
roof terminal A
Concentric flue gas system: maximum noted length = distance between boiler and
roof terminal B
When using bends the noted value behind every bend should be deducted from the
maximum straight length.
Pipes with 60/100 diameter are only permitted on wall terminals in
combination with ATAG boilers untill 25kW.
ø80mm
A
in m ø100mm
A
in m
16-25 kW Maximum straight lenth 80 31 Maximum straight lenth 100 40
87° bend resistance length -1,5 87° bend resistance length -1,8
45° bend resistance length -0,8 45° bend resistance length -0,9
26-38 kW Maximum straight lenth 80 18 Maximum straight lenth 100 39
87° bend resistance length -1,5 87° bend resistance length -1,8
45° bend resistance length -0,8 45° bend resistance length -0,9
39-60 kW Maximum straight lenth 80 6 Maximum straight lenth 100 18
87° bend resistance length -1,5 87° bend resistance length -1,8
45° bend resistance length -0,8 45° bend resistance length -0,9
ø60/100mm
B
in m ø80/125mm
B
in m ø100/150mm
B
in m
16-25 kW Maximum straight lenth 60/100 12 Maximum straight lenth 80/125 31 Maximum straight lenth 100/150 40
87° bend resistance length -1 87° bend resistance length -2,8 87° bend resistance length -2,6
45° bend resistance length -1 45° bend resistance length -1,1 45° bend resistance length -1,1
26-38 kW Maximum straight lenth 80/125 13 Maximum straight lenth 100/150 34
87° bend resistance length -2,8 87° bend resistance length -2,6
45° bend resistance length -1,1 45° bend resistance length -1,1
39-60 kW Maximum straight lenth 80/125 6 Maximum straight lenth 100/150 10
87° bend resistance length -2,8 87° bend resistance length -2,6
45° bend resistance length -1,1 45° bend resistance length -1,1
Concentric flue system
Two pipe flue system + chimney lining
Dimensions flue gas system and air supply system Table 5
Example:
A 25kW with a
concentric flue gas system
ø80/125mm has according to
the table a maximum flue
straight length of 31m In the
systemthatisgoingtobeputin
thereare 2 x45° bends, sothe
maximum flue gas length is
40 – ( 2 x 1.1 ) = 37.8 meters.

Installation&ServicingInstructionsATAG
20
Q
7 External hot water cylinders
Depending of the comfort preferences different external hot water cylinders can be
connected to the boiler. The choice of the cylinder depends on the coil output. The coil
output must comply with the boiler output.
Acylinder which is used in combination witha Q 51S or Q 60S,should have a minimal
capacityof40kWresp.45kW (minimalø28mmcoil).Themaximumpermittedpressure
drop is respectively 20 and 10 kPa at a flow of respectively 1417 and 1587 l/h.
Seeinstallation example 16.2 on page 37 for the hydraulic connection.