Ariston COMBI A 24 MFFI, COMBI A 30 MFFI User Manual

Installation, Servicing and
Operating Instructions

Type C Boilers

COMBI A 24 MFFI G.C.N: 47-116-44
COMBI A 30 MFFI G.C.N: 47-116-45

LEAVE THESE INSTRUCTIONS
WITH THE END USER

Country of destination: GB/IE

These instructions are suitable for the COMBI A boilers :

MTS (GB) Limited supports Benchmark, the heating industry code to ensure the correct installation, commissioning and
servicing of domestic central heating systems.

To The Householder

Make sure that your installer completes Section 24 of this manual (page 60) .

commissioning of your boiler.

It contains important information about your particular installation that may be required by service engineers. It will also provide
contact details for the installer should you need guidance in the use of this appliance or if there are any problems.

As with your car, your boiler will work more reliably and efficiently if regularly serviced. We recommend an annual service
check. The service history of the appliance must be recorded in Section 25 of this manual (page 61).

In the unlikely event of any problems with your boiler or system you should first contact your installer. If your installer cannot
resolve the problem he should telephone our national service helpline.

A charge may be made if MTS (GB) Limited is called out to resolve a non-product related fault.

Your statutory rights are not affected.

To The Installer

As part of the commissioning of this appliance it is necessary to complete Section 24 of this manual (page 60) and give this
manual to the Householder. Please ensure that your customer is aware of the importance of keeping this manual safe as a
record of the installation (Section 24, page 60) and the appliance service history (Section 25, page 61).

Please ensure that your customer is aware of the correct operation of the system, boiler and controls.

This provides a record of the

MTS recommend the use of protective clothing, when installing and working on the appliance i.e. gloves.

CUSTOMER CARE

The MTS Group as a leading manufacturer of domestic and commercial water heating appliances is committed to providing
high quality products and a high quality after sales service.

Advice on installation or servicing can also be obtained by contacting the Ariston Technical and Customer Service
Departments on:

TECHNICAL DEPARTMENT CUSTOMER SERVICE DEPARTMENT

Tel: [phone] Tel: [phone]

Fax: [phone] Fax: [phone]

GUARANTEE

The manufacturer’s guarantee is for 2 years from the date of purchase. The guarantee is invalidated if the appliance is not
installed in accordance with the recommendations made herein or in a manner not approved by the manufacturer. To assist us
in providing you with an efficient after sales service, please return the guarantee registration card enclosed with the boiler
without delay.

CAUTION

In the United Kingdom, installation, start-up, adjustments and maintenance, must be performed by a competent person only, in
accordance with the current Gas Safety (Installation & Use) Regulations and the instructions provided.

In the Republic of Ireland, the installation and initial start up of the appliance must be carried out by a Competent Person in
accordance with the current edition of I.S.813 “Domestic Gas Installations”, the current Building Regulations, reference should
also be made to the current ETCI rules for electrical installation.

All CORGI registered installers carry a CORGI ID card, and have a registration number. Both must be recorded in
your boiler Log Book. You can check your installer is CORGI registered by calling CORGI direct on:- [phone].

Improper installation may cause damage or injury to individuals, animals and personal property for which the manufacturer will
not be held liable. To ensure efficient and safe operation it is recommended that the boiler is serviced annually by a competent
person.

If it is known that a fault exists on the appliance, it must not be used until the fault has been corrected by a competent person.

This instruction booklet is especially designed for appliances installed in the UK and the Republic of Ireland

2

Contents

CUSTOMER CARE

Guarantee ............................................................................................................................................................2

Statutory Requirements .......................................................................................................................................2

Contents ...............................................................................................................................................................3

INTRODUCTION ..................................................................................................................................................4

USER INSTRUCTIONS ........................................................................................................................................5

1 CONTROL PANEL...........................................................................................................................................5

2 HOW TO USE ..................................................................................................................................................6

3 MAINTENANCE ...............................................................................................................................................7

4 GUARANTEE...................................................................................................................................................7

5 PRACTICAL INFORMATION...........................................................................................................................7

6 SETTING THE TIME CLOCKS ........................................................................................................................8

6.1 SETTING THE MECHANICAL CLOCK ...................................................................................................8

6.2 SETTING THE DIGITAL CLOCK.............................................................................................................9

INSTALLERS’ INSTRUCTIONS.........................................................................................................................11

7 DESCRIPTION...............................................................................................................................................11

8 DIMENSIONS ................................................................................................................................................12

9 HYDRAULIC DATA .......................................................................................................................................13

10 INSTALLATION REQUIREMENTS................................................................................................................14

11 INSTALLING THE BOILER............................................................................................................................17

12 CONNECTING THE FLUE.............................................................................................................................19

12.1 FITTING THE COAXIAL FLUE (Ø 60 / 100 HORIZONTAL) ................................................................ 20

12.2 FITTING THE 5” FLUE (Ø 80 / 125 HORIZONTAL/VERTICAL) .......................................................... 20

....................................................................................... 22

12.3 FITTING THE

12.4 FITTING THE TWIN FLUE (

13 ELECTRICAL CONNECTIONS .................................................................................................................... 26

13.1 FITTING THE MECHANICAL AND DIGITAL TIME CLOCKS ............................................................. 28

14 COMMISSIONING AND TESTING ...............................................................................................................

14.1 INITIAL PREPARATION ....................................................................................................................... 29

14.2 INITIAL START-UP............................................................................................................................... 29

14.3 ADJUSTING THE CO2 ......................................................................................................................... 30

14.4 GAS CONVERSION ............................................................................................................................. 30

14.5 ADJUSTING THE MAXIMUM HEATING POWER ............................................................................... 30

14.6 FITTING THE EXTERNAL SENSOR

14.7 EXTERNAL SENSOR SET-UP............................................................................................................. 31

14.8 SETTING THE PARALLEL SHIFT........................................................................................................ 31

14.9 COMPLETION

14.10 OPERATIONAL CHECKS .................................................................................................................... 32

14.11 INSTRUCTING THE END USER.......................................................................................................... 32

15 FITTING THE CASING .................................................................................................................................

16 SEQUENCE OF OPERATION...................................................................................................................... 34

16.1 CENTRAL HEATING MODE ................................................................................................................ 34

16.2 DOMESTIC HOT WATER MODE......................................................................................................... 35
17 ADJUSTMENTS AND SETTINGS

VERTICAL FLUE (

......................................................................................................................................

Ø 60 / 100

80 / 80) ................................................................................................ 23

Ø

.................................................................................................... 30

................................................................................................................ 36

)

Page

29

31

33

3

SERVICING INSTRUCTIONS

18 REPLACEMENT OF PARTS ........................................................................................................................ 43

18.1 TO GAIN GENERAL ACCESS ................................................................................................................ 43

18.1.1 Removing the front panel...................................................................................................................... 43

18.1.2 Lowering the control panel.................................................................................................................... 43

18.2 ACCESS TO THE COMBUSTION CHAMBER ........................................................................................ 44

18.2.1 Removing the combustion chamber front panel ................................................................................... 44

18.2.2 Removing the burner ............................................................................................................................ 45

8.2.3Removing the detection electrode ........................................................................................................ 45

1

18.2.4 Removing the ignition electrode............................................................................................................ 45

8.2.5Removing the fan.................................................................................................................................. 46

1

18.2.6 Removing the gas valve........................................................................................................................ 46

18.2.7 Removing the heat exchanger .............................................................................................................. 47

18.2.8 Removing the spark generator.............................................................................................................. 47

18.3 ACCESS TO THE WATER CIRCUIT ...................................................................................................... 48

18.3.1 Drain down............................................................................................................................................ 48

18.3.2 Removing the 3 way valve.................................................................................................................... 48

18.3.3 Removing the float of the flow switch ................................................................................................... 48

18.3.4 Removing the secondary heat exchanger

............................................................................................ 49

18.3.5 Removing the pump.............................................................................................................................. 49

18.3.6 Removing the pressure relief valve ..................................................................................................... 50

18.3.7 Removing the domestic expansion vessel

............................................................................................ 50

18.3.8 Removing the overheat thermostat....................................................................................................... 50

18.3.9 Removing the temperature sensors (NTC’s) ........................................................................................ 50

18.3.10 Removing the pressure gauge.............................................................................................................. 50

18.3.11 Removing the DHW flow switch............................................................................................................ 51

18.4 ACCESS TO THE CONTROL SYSTEM.................................................................................................. 51

18.4.1 Removing the PCB’s............................................................................................................................. 51

18.4.2 Removing the fuses .............................................................................................................................. 52

18.5 CONNECTING THE EXTERNAL SENSOR ............................................................................................ 52

19 INCORRECT FUNCTION ............................................................................................................................. 53

20 MAINTENANCE INSTRUCTIONS ................................................................................................................ 54

20.1 GENERAL REMARKS ............................................................................................................................. 54

20.2 CLEANING THE PRIMARY EXCHANGER ............................................................................................. 54

20.3 OPERATIONAL TEST ............................................................................................................................. 55

21 SHORT SPARES LIST ................................................................................................................................. 56
22 NOTES

.......................................................................................................................................................... 57

23 TECHNICAL DATA ....................................................................................................................................... 58

24 BENCHMARK COMMISSIONING CHECKLIST ........................................................................................... 60

25 SERVICE INTERVAL RECORD ................................................................................................................... 61

TERMS AND CONDITIONS OF GUARANTEE ............................................................................................ 64

INTRODUCTION

The COMBI A is a fully automatic, wall mounted, low water content condensing combination boiler. It is a room
sealed, fan assisted, appliance providing central heating and mains pressure domestic hot water on demand. It
has electronic ignition and is suitable for all modern electrical control systems. The boiler is designed for sealed
systems only and a circulating pump, expansion vessel together with a pressure gauge and safety valve are
included within the boiler.

The COMBI Arange of boilers are domestic gas boilers and intended for domestic use only.

4

1. Control Panel

USER INSTRUCTIONS

16

29

Fig. 1

Control panel (Fig. 1)

16.- Pressure gauge

25.- Display

26.- On/off push button and power on indicator light

27.- Yellow indicator - Comfort button

28.- Reset push button and red indicator lock-out light

29.- DHW control knob and temperature setting

30.- Central Heating control knob and temperature setting

31.- Menu button

32.- Reducing button

33.- Increasing button

34.- Setting button

26

31

25

Connecting bracket

Taps shown in Open position (Fig. 2)

39.- Gas Service Tap

40.- Water Service Tap

41.- Central Heating Flow Isolating Valve

42.- Central Heating Return Isolating Valve
43 & 44.- Filling Taps

45.- Filling Loop

27

32

33

28

34

30

41

43

Fig. 2

45

39

42

44

40

5

2. How to Use

+

+

Switching on and filling instructions

1. Check the pressure in the central heating system is above 0.7 bar and below 1.5 bar with the pressure gauge 16 (fig.1),

should it be necessary to re-pressurise the system,ensure the filling loop
the pressure gauge will now start to rise, once the pressure reads 1.0 bar, close the filling taps and disconnect the filling

oop.

l

2. Check that the gas service tap is opened at the gas meter and the main power is on. Green indicator
fig.2).

. Open the gas tap

3

39(

4. The boiler is now ready to use.

NOTE: If the boiler is left off for a long time, some air in the gas pipe can hinder the first lighting

attempts. (please refer to Section 19 Incorrect Function, page 53)

Time setting

You can set the time by using the keys underneath the display.
Press the setting button for more than 5 seconds, the hours will begin to flash. You can now set the correct hour by using the +
and - keys. Pressing the setting button again will make the minutes flash. You can set the minutes by using the + or - buttons.
Pressing the setting button once more will store the set time.

NOTE:THIS IS NOT A TIMER FOR CH CONTROL

45 (fig. 2) is attached, open the filling taps 43 & 44,

26 Power ON

OPEN CLOSED

DHW mode

Turn the control knob 29 between min and max. During the adjustment,
flashes.
The flashing goes on for a while after the adjustment, then the display indicates
the time.

When DHW is drawn, the
display indicates the following:

Comfort mode

To activate the comfort mode it is necessary to press the comfort button, this
will be indicated by a yellow light. The comfort mode has priority over any other
heating request.
There are two settings for the comfort mode (they can be adjusted in the
parameters menu, see Section 17

Adjustments and Settings):

1. As soon as DHW is drawn, the secondary heat exchanger is kept warm for
30 mins.
As soon as DHW

2.

is drawn, the secondary heat exchanger is kept warm

permanently.

When the boiler is operating in ‘comfort
mode’ the display indicates the following:

Heating mode

Turn the control knob 30 between min and max. During the adjustment
flashes.
The flashing goes on for a while after the adjustment, the display will then
indicate:

- the central heating flow temperature if the room thermostat is calling for heat.

- the time if the room thermostat is OFF.

comfort

BURNER ON and output level

The flame digits will increase or decrease depending on the output.

6

Room thermostat request

symbol

Flame digit

Burner ON

Stand-by mode

Turn the control knobs 29 and 30 to the OFF position to deactivate the DHW
and Heating. Leave the ON/OFF button On with the green light on.

uring the stand-by mode the display indicates the time, anti-seizing and anti-

D
freezing will be active, see below.

Switch OFF

Press the ON/OFF button.

During this mode the boiler will not operate, but is still connected to the mains.

Anti-freezing mode

urn the control knobs 29and 30toOFFto switch off the heating and hot water

T
functions. Leave the On/Off button on with the green light on.
When the anti-freeze comes on, the corresponding code is displayed with the
snowflake pictogram .

The two possible codes are 05 (anti-freeze - pump only) or 06 (anti-freeze ­burner).

When this mode is active, the circulating pump operates for one

05:
minute and the diverter valve switches every 23 hours.
Caution: in this mode, the room thermostat anti-freeze function is
inoperative.

Boiler anti-freeze function: the pump starts at 8°C

the burner starts at 3°C

3. Maintenance

Your boiler will work more reliably and efficiently if regularly serviced. We recommend an annual service check. The service
history of the appliance will be marked in the Service Interval Record (Section 25, page 61).

4. Guarantee

The manufacturer`s guarantee is for 2 years from the date of purchase. The guarantee is voidable if the appliance is not
installed in accordance with the recommendations made herein or in a manner not approved by the manufacturer. To assist us
in providing you with an efficient after sales service, please return the guarantee registration card enclosed with the boiler with­out delay.

5. Practical Information

Cleaning the casing and control panel

Should it be necessary to clean the casing and control panel. do so only with a soft damp cloth, do not use any spray polishes
or cleaners.

Precaution to avoid freezing

We recommend you contact your installer or local service centre for further advice on the actions to be taken to avoid the
system freezing (Should the boiler be turned off at the mains electrical isolator).

DHW system

•

Turn off the main cold water supply and drain the boiler :

- Open a hot water tap

- Unscrew the cold water inlet tail

system

CH

•

Choose one of the following solutions :

- 1) Drain completely the Central Heating system

- 2) Protect the Central Heating system with anti freeze chemical products and verify the concentration periodically
C)

- 3) Leave the Heating mode switched on and set the room thermostat to anti-freeze mode (between 5 and 10

- 4) Leave your boiler in stand by mode, the anti-freeze device will switch on the pump and the burner if necessary.

°

7

3

6

9

12

11

22

33

44

55

66

77

88

99

1010

1111

1212

1313

1414

1515

1616

1717

1818

1919

2020

2121

2222

2323

2424

99

66

1212

I

6. Setting the time clocks (continued)

6.1 Setting the Mechanical Clock

Fig. 3

A

Fig. 4

1. General layout
The mechanical clock covers a 24 hour period. Each tappet represents 15 minutes A (Fig. 4). An override switch is located on

B (Fig 4).

symbol to control the central heating by the clock. Put the switch

B to «I» to select

the clock

2. To set the time

To set the time of day, grasp the outer edge of the dial and turn slowly clockwise until the correct time is lined up with the arrow

C (Fig. 4).

3. To Set the "On" and "Off" times

The clock uses a 24 hour system. e.g. 8 = 8.00 am and 18 = 6.00 pm "ON" periods are set by sliding all tappets between the
"ON" time and the "OFF" time to the outer edge of the dial.The tappets remaining at the centre of the dial are the "OFF"
periods.

4. For operation

Put the selector switch B to the
permanent operation or to «0» to turn the central heating off permanently.

C

B

8

6. Setting the time clocks (continued)

6.2 Setting the Digital Clock

Operating the time switch

The steps marked with the symbol “ ” are necessary to carry out a switching program.

Preparing for Operation

Activate the “Res” switch (=RESET) to reset the time switch to its default setting (activate using a pencil or similar pointed
instrument). Do this:

- every time you wish to “reset” the time switch

- to erase all switching times and the current time of day.
After approximately two seconds the following display appears:

Enter current time and weekday

- Keep the “ ” button pressed down
During the summer time period press the +/- 1h button once.
Enter the hour using the “h” button
Enter the minutes using the “m” button
Enter the day using the “Day” button

1 = “Monday”..............7 = Sunday

- Release the “ ” button.

9

6. Setting the time clocks (continued)

Entering the switching times

ou have 20 memory Iocations available. Each switching time takes up one memory location.

Y

eep pressing the “Prog” button until a free memory location is shown in the display “– –:– –”.

K

rogramme ON or OFF with the “ ” button:

P
“ ”= OFF; “ ”= ON
Enter the hour using “h”
Enter the minutes using “m”
If a switching command is to be carried out every day (1 2 3 4 5 6 7) then store using the “ ” button, otherwise select the
day(s) it is to be carried out by using the “Day” button.
When the day seIection is left bIank, the programmed switching instruction operates at the same time every day

2 3 4 5 6 = Monday – Saturday

1

2 3 4 5 = Monday – Friday

1

7 =Saturday – Sunday

6

Selection of single days: 1 = Mon. .............. 2 =Tues.
Save the switching time with the “ ” key.
The time switch enters the automatic operating mode and displays the current time of day.
Begin any further entry of a switching time with the “Prog” switch. If your entry is incomplete, the segments not yet selected
will blink in the display. After programming is completed, and you return the time clock to the current time display with the “
” key, the time clock will not activate any switching instruction required for the current time. You may need to manually select
the desired switching state with the “ ” key. Thereafter, as the unit encounters further switching instructions in the memory
in real time, it will correctly activate all subsequent switching instructions.

Manual Override Switch “ ”

With the “ ” you can change the current setting at any time. The switching program already entered is not altered.

Reading the programmed switching times

Pressing the “Prog” button displays the programmed switching times until the first free memory location appears in the display “–
– : – –”.

If you now press the “Prog” button once again, the number of free memory Iocations will be displayed, e.g. “
locations are occupied, the display “

Changing the programmed switching times

Press the “Prog” button repeatedly until the switching time you want to change is displayed. You can now enter the new data.

Entering the switching times”.

See “

Notes on storing switching times:

If you end your entry of the switching times by pressing the “Prog” key, then the switching time you have entered will be stored
and the next memory location displayed.

In addition, a complete switching command is stored
pressed. The time switch then enters the automatic operating mode and displays the current time again.

Deleting individual switching times

Press the “Prog” button repeatedly until the switching time you wish to delete is shown in the display. Then set to “– –” using the
“h” or “m” button and keep the “ ” button pressed down for around 3 seconds. The switching time is now erased and the current
time is displayed.

00” appears.

automatically after around 90 seconds provided no other button is

18”. If all memory

AM / PM time display

If you press the “+/-1h” and “h” keys at the same time, the time display switches into the AM/PM mode.

10

7. Description

10

2

3

8

20

22

21
12

6

INSTALLER INSTRUCTIONS

- Steel chassis complete with expansion vessel

1

9

7

4

5

42

1.

2.- Sealed chamber

3.- Burner and heat exchanger assembly

4.- Air / gas connection

- 24 V modulating fan

5.

6.- Gas valve

- Ignition electrode

7.

8.- Ionisation probe

- Ignitor

9.

10.- Combustion products manifold

11.- Condense trap

12.- Silencer

- Electrical box

13.

14.- Pump

15.- Secondary heat exchanger

16.- Pressure gauge

17.- Three way valve

18.- Automatic air vent
19 - Domestic hot water flow switch

20.- Primary flow thermistor

21.- Primary return thermistor

22.- Overheat sensor

23.- Central heating pressure relief valve

13

16

Fig. 5

29

26

25

27

28

14

15

23

11

Fig. 6

30

25.- Display

On/off push button and power on

26.-

indicator light

27.- Yellow indicator - Comfort button

28.- Reset push button and red indicator

lock-out light

29.- DHW control knob and temperature

setting

30.- Central Heating control knob

temperature setting

31.- Menu button

32.- Reducing button

33.- Increasing button

34.- Setting button

and

17

18

19

Fig. 7

31

32

33

34

11

8. Dimensions

440

450 mini pour entretien

All dimensions in mm

96 (24 kW)

2
360 (30 kW)

afety valve C/H and condensate

I S

eating flow

J

H

K

D.H.W. outlet

L

Gas supply

M

Cold water inlet

N

Heating return

eight with packaging :

W

24 kW : 37 kg
30 kW : 40 kg

Minimum space required 450mm

Fig. 9

390 mm

12

NOTE:THE CLEARANCES STATED ABOVE ARE REQUIRED FOR SERVICING PURPOSES

9. Hydraulic data

20 40 60 80 100 120 140 160 180 200 220 240

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1,8

1.9

2.0

260 280

40°C

50°C

60°C

70°C

80°C

0

0.05

0

.1

0

.15

0

.2

0

.25

0.3

0.35

0

.4

0.45

0

200 400 600 800 1000 1200 1400

The boiler is fitted with an automatic by-pass as standard.

The graphs (Fig. 10) show the development of the pressure
available in relation to flow (on exit from the boiler).

To ensure correct operation, the minimum flow of the
appliance must be 300 l/h. (Thermostatic taps closed).

Capacity of the installation.

The water heater is fitted with a pressurised expansion

essel.

v

aximum volume of expansion vessel: 6 litres.

M

ressure: 1 bar.

P

Pump Head Graph (15/50)

Pressure (bar)

The volume of the expansion vessel in a pressurised

ppliance varies according to:

a

- the average operating temperature in °C

- the static height, which is the difference in metres between
the highest point of the appliance and the expansion vessel

xis.

a

The minimum cold filling pressure of the appliance is 0.8 bar

recommended pressure between 1.0 and 1.5 bar).

(

The pressure of the expansion vessel should always be
greater than the static height (in metres) divided by 10.

flow rate (l/hr)

Pump Head Graph (15/60)

Pressure (bar)

flow rate (l/hr)

System capacity chart

Central heating initial pressure when cold (in bar)

System capacity (litres)

Fig. 10

Fig. 11

13

E

E

10. Installation requirements

Reference Standards

n the United Kingdom, the installation and initial start up of

I
the boiler must be by a CORGI Registered installer in
accordance with the installation standards currently in effect,
as well as with any and all local health and safety standards
i.e. CORGI.

In the Republic of Ireland the installation and initial start up of
the appliance must be carried out by a Competent Person in
accordance with the current edition of I.S.813 “Domestic Gas
Installations” and the current Building Regulations, reference
should also be made the the current ETCI rules for electrical

nstallation.

i

he installation of this appliance must be in accordance with

T
the relevant requirements of the Local Building Regulations,
the current I.E.E. Wiring Regulations, the by-laws of the local
water authority, in Scotland, in accordance with the Building
Standards (Scotland) Regulation and Health and Safety
document No. 635, “Electricity at Work Regulations 1989”
and in the Republic of Ireland with the current edition of I.S.
813 and the Local Building Regulations (IE).

For detailed information on the installation of Condensing
boilers, reference should be made to the

ODPM Guide to
the Condensing Boiler Assesment Procedure for
Dwellings

.

exposed to the free passage of external air at all times and

ust not be installed in a place likely to cause nuisance. It

m
must not be allowed to discharge into another room or space
such as an outhouse or closed lean-to.

Condensing boilers have a tendency to form a plume of water
vapour from the flue terminal due to the low temperature of the
flue gasses. The terminal should therefore be located with due
regard for the damage or discolouration that might occur to
buildings in the vicinity and consideration must also be given to
adjacent boundaries, openable windows should also be taken
into consideration when siting the flue.

Fig. 11

C.O.S.H.H.

Materials used in the manufacture of this appliance are non­hazardous and no special precautions are required when
servicing.

Codes of Practice

Installation should also comply with the following British
Standards Codes of Practice:

BS 7593:1992 Treatment of water in domestic hot

water central heating systems

BS 5546:2000 Installation of hot water supplies for

domestic purposes
BS 5440-1:2000 Flues
BS 5440-2:2000 Air Supply
BS 5449:1990 Forced circulation hot water systems
BS 6798:2000 Installation of gas fired hot water

boilers of rated input not exceeding

70kW
BS 6891:2000

Installation of low pressure gas pipe up

to 28mm
BS 7671:2001 IEE Wiring Regulations
BS 4814:1990 Specification for expansion vessels
BS 5482:1994 Installation of L.P.G.

and in the Republic of Ireland in accordance with the
following codes of practice:

The minimum acceptable clearances are shown below:

A - Directly below an open window or other opening 300
B - Below gutters, solid pipes or drain pipes 75
C - Below eaves 200
D - From vertical drain pipes and soil pipes 75
E - From internal or external corners 300
F - Above ground on a public walkway or patio 2100
G - From a surface facing a terminal 2500
H - From a terminal facing a terminal 2500

Vertically from a terminal in the same wall 1500

-

I
J - Horizontally from a terminal in the same wall 300
K - Horizontally from an opening window 300

Fixed by vertical flue terminal

-

L

NOT BE INSTALLED IN A PLACE LIKELY TO

NOTE:

T

HE

CAUSE

MUST

FLUE

A NUISANCE

.

It may be necessary to protect the terminal with a guard, if this is
the case it will be necessary to purchase a stainless steel terminal
guard. Reference should be made to the Building Regulations for
guidance.

I.S. 813 Domestic Gas Installations

Avoid installing the boiler where the air inlet can be polluted
by chemical products such as chlorine (swimming pool area),
or ammonia (hair-dresser), or alkaline products (launderette)

Flue

Detailed information on flue assembly can be found in Section
12 “Connecting the flue”

.

The boiler must be installed so that the flue terminal is

14

Ventilation

The room in which the boiler is installed does not require specific
ventilation. If it is installed in a cupboard or compartment

permanent ventilation is not required for cooling purposes.

Gas Supply

The gas installation and soundness testing must be in
accordance with the requirements of BS 6891. Ensure that
the pipe size is adequate for demand including other gas
appliances on the same supply.

10. Installation requirements (continued)

lectrical Supply

E

All electrical work carried out must be in accordance with all

urrent local Building Regulations and British Standards.

c
The appliance requires an earthed 230V - 50 Hz supply and

ust be in accordance with current I.E.E. It must also be

m
possible to be able to completely isolate the appliance

lectrically. Connection should be via a 3 amp fused double-

e
pole isolating switch with contact separation of at least 3 mm
on both poles. Alternatively, a fused 3 Amp. 3 pin plug and
unswitched socket may be used, provided it is not used in a
room containing a bath or shower. It should only supply the
appliance.

The boiler is suitable for sealed systems only. The maximum
working pressure for the appliance is 6 bar. All fittings and

ipework connected to the appliance should be of the same

p
standard. If there is a possibility of the incoming mains
pressure exceeding 6 bar, particularly at night, then a
suitable pressure limiting valve must be fitted.
The boiler is designed to provide hot water on demand to
multiple outlets within the property. If there is a requirement
for greater demands, for example if the property has several
bathrooms and cloakrooms, a vented or unvented hot water
storage system may be used.

Showers

Any shower valves used with the appliance should be of a
thermostatic or pressure balanced type. Refer to the shower
manufacturer for performance guidance and suitability.

Flushing and Water Treatment

The boiler is equipped with a stainless steel heat exchanger.

The detailed recommendations for water treatment are given
in BS 7593:1992 (Treatment of water in domestic hot water
central heating systems); the following notes are given for
general guidance;

If the boiler is installed on an existing system, any
unsuitable additives must be removed;

Under no circumstances should the boiler be fired before the
system has been thoroughly flushed; the flushing procedure
must be in line with BS7593:1992.

We highly recommend the use of a flushing detergent
appropriate for the metals used in the circuit, whose function
is to dissolve any foreign matter that may be in the system.

In hard water areas or where large quantities of water are in
the system the treatment of the water to prevent premature
scaling of the main heat exchanger is necessary.

The formation of scale strongly compromises the efficiency of
the thermic exchange because small areas of scale cause a
high increase of the temperature of the metallic walls and
therefore add to the thermal stress of the heat exchanger.

Demineralised water is more aggressive so in this situation it
is necessary to treat the water with an appropriate corrosion
inhibitor.

Any treatment of water by additives in the system for frost
protection or for corrosion inhibition has to be absolutely
suitable for all the metals used in the circuit.

he use of a corrosion inhibitor in the system is

T
recommended to prevent corrosion (sludge) damaging the

oiler and system;

b

f anti-freeze substances are to be used in the system, check

I
carefully that they are compatible with the metals used in the

ircuit.

c

MTS suggests the use of suitable anti-freeze products, which
will prevent rust and incrustation taking place.

Periodically check the pH of the water/anti-freeze mixture of
the boiler circuit and replace it when the amount measured is
out of the range stipulated by the manufacturer ( 7 < pH < 8).
DO NOT MIX DIFFERENT TYPES OF ANTI-FREEZE

In under-floor systems, the use of plastic pipes without
protection against penetration of oxygen through the walls
can cause corrosion of the systems metal parts
(metal piping, boiler, etc), through the formation of oxides
and bacterial agents.

To prevent this problem, it is necessary to use pipes with an
“oxygen-proof barrier”, in accordance with standards DIN
4726/4729

system separate by installing heat exchangers of those
with a specific system water treatment.

IMPORTANT
Failure to carry out the water treatment procedure will
invalidate the appliance warranty.

System Controls

The boiler is electrically controlled and is suitable for most
modern electronic time and temperature controls. The
addition of such external controls can be beneficial to the
efficient operation of the system, please refer to local
Building Regulations for further advice. The boiler
connections for external controls are 12V DC and so only
controls of 12V DC that have voltage free contacts should be
used. (Section 13 Electrical Connections - page 26).

Location

The boiler can be installed on any suitable internal wall.
Provision must be made to allow the correct routing of the flue
and siting of the terminal to allow the safe and efficient removal
of the flue products. A compartment or cupboard may be used
provided that it has been purpose-built or modified for the
purpose. It is not necessary to provide permanent ventilation
for cooling purposes. Detailed recommendations are given in
BS 5440 pt 2. If it is proposed that it is installed in a timber
framed building then reference should be made to British Gas
Document DM2, or advice sought from CORGI.

Where a room sealed appliance is installed in a room
containing a bath or shower, the appliance and any
electrical switch or appliance control, utilising mains
electricity should be situated specifically in accordance
with current IEE

For unusual locations, special procedures may be necessary.

BS 6798:2000 gives detailed guidance on this aspect.

Condensate Discharge

The condensate discharge hose from the boiler must have a
continuous fall of 2.5
into a suitable acid resistant pipe - e.g. plastic waste or

. If pipes of this kind are not used, keep the

Wiring Regulations.

o

and must be inserted by at least 50mm

15

10. Installation requirements (continued)

verflow pipe. The condensate discharge pipe must have a

o
minimum diameter of 22mm, must have a continuous fall and
preferably be installed and terminated to prevent freezing.
The discharge pipe must be terminated in a suitable position:

i) Connecting into an internal soil stack (at least 450mm

bove the invert of the stack). A trap giving a water seal

a
of at least 75mm must be incorporated into the pipe run,
there also must be an air break upstream of the trap.

ii) Connecting into the waste system of the building such as

a washing machine or sink trap. The connection must be
upstream of the washing machine/sink. If the connection

s down stream of the waste trap then an additional trap

i
giving a minimum water seal of 75mm and an air break

1. Internal termination of condensate drainage pipe to
internal stack

ust be incorporated in the pipe run, as above.

m

iii) Terminating into a gully, below the grid level but above

the water level.

iv) Into a soakaway.

N

O

: If any condensate pipework is to be installed

TE

xternally then it should be kept to a minimum and be

e
insulated with a waterproof insulation and have a continuous
fall. The total length of external pipe used should not exceed
3 metres.

Some examples of the type of condensate terminations can

e found below.

b

2. External termination of condensate drainage pipe via
internal discharge branch (e.g. sink waste) and condensate
siphon

3. External termination of condensate drainage pipe via
internal discharge branch (e.g. sink waste - proprietary fitting).

16

4. External termination of condensate drainage pipe via
condensate siphon

11. Installing the boiler

Please check that you are familiar with the installation requirements before commencing work (Section 10).

The installation accessories described in the following list are included in the boiler packaging:

- Hanging bracket
A paper template (showing the dimensions of the boiler with 5 mm side clearances)

-

- Connection tails and valves

- Screws and washers

- Connection washers

- Installation, Servicing and Operating Instructions

ethod of positioning the boiler on the wall.

M

The paper template can be used to ensure the correct positioning of kitchen cabinets etc. It also details the commissioning
instructions.
The paper template has to be fixed to the wall and used to locate the position of the hanging bracket and the centre for the flue

ole.

h
Drill and plug the wall and secure the hanging bracket using the screws provided. Remove the boiler from its packaging as
shown in Fig. 16 and unscrew the two clamp locking bolts
Place the boiler on the wall on the hanging bracket (Fig. 14).

NOTE: TH

Connecting the boiler to the system

- Remove the boiler casing as described in Section 18.

- Push in the tabs “

- Remove the caps and connect the boiler to the taps using the washers provided in the plastic bag.

E APPLIANCE MUST NOT BE FITTED ON A COMBUSTIBLE WALL SURFACE

P” (Fig. 14) on either side of the boiler and pivot the electrical box forward to gain access to the valve

connections

4 x fibre washers for the C/H flow and return, hot water outlet and cold water inlet connections
1 x rubber washer for gas connection

A and remove the casing (Fig. 13).

.

Safety valve discharge

The pressure relief valve tube is made of copper. It should terminate below the boiler safely outside the premises. Care should
be taken that it does not terminate over an entrance or window or where a discharge of heated water could endanger
occupants or passers by.

Fill the Central Heating and DHW system and bleed air from the system as described in Section 14.
The system should be carefully checked for leaks, as frequent refilling could cause premature system corrosion or
unnecessary scaling of the heat exchanger. The pipe from the condense trap (11 Fig. 5) should be connected to a drain as
described in the relevant British regulations.
Pay special attention to not bend the condensate silicone drain pipe such as the flow will be interrupted. Please use exclusively
drain pipe material compatible with condensate products. (refer to
The condensate flow can reach 2 litres / hour; because of the acidity of the condensate products (Ph close to 2), take care
before operation.

Fitting the Horizontal Flue
Attention ! Before starting the boiler, the condensate trap (11 Fig. 5) must be filled with water. Before fitting the flue l
onto the boiler, pour 1/4 litre of water in the exhaust pipe as shown in Fig. 16.

Instructions on fitting the flue can be found in Section 12.

IMPORTANT!!

Use only the specific condensation flue kit supplied by MTS.

BS 6798 : 2000)

17

1

2

11. Installing the boiler (continued)

ig. 12

F

A

A

Fig. 13

P

P

Fig. 14

18

Fig. 15

5

12. Connecting the Flue

118

The boiler should only be installed with a flue system supplied by MTS (GB) Limited.
These kits are supplied separately to the appliance in order to respond to different installation solutions. For more information
with regard to the inlet/outlet accessories consult the accessory catalogue. The boiler is supplied ready for connection to a

oncentric flue system.

c

O

:SE

N

TE

IMPORTANT!!

BEFORE CONNECTING THE FLUE, ENSURE THAT 1

WATER HAS BEEN POURED INTO THE EXHAUST CONNECTION
TO FILL THE CONDENSATE TRAP (FIG. 16). SHOULD THE

T

RAP BE EMPTY THERE IS A TEMPORARY RISK OF FLUE

GASSES ESCAPING INTO THE ROOM

E PAGE

24 F

OR MAXIMUM AND MINIMUM FLUE RUNS

.

(TA

/4

LITRE OF

BLES

A, B ANDC)

ig. 16

F

Warning

The exhaust gas ducts must not be in contact with or close to inflammable
material and must not pass through building structures or walls made of
inflammable material.
When replacing an old appliance, the flue system must be changed.

Ø 60/100 mm

Fig. 17

Installation without extension

Important

Ensure that the flue is not blocked.
Ensure that the flue is supported and
assembled in accordance with these
instructions.

Level

Installation with extension

Fig. 18

Level

19

12.1 Fitting the coaxial flue (Ø 60/100 Horizontal)

CO
1X SI

NTENTS

LICONE

:

-R

I

NG

60mm)

(

O
1X ELBOW (90O)
2X WALLSE

X FLUE PIPE INCLUDING TERMINAL (1 METRE - 60/100)

1
1X FLUECL
1X SC

REWS

x Seal

1

Once the boiler has been positioned on the wall, insert the elbow into the socket and rotate to the required position. N

ALS

AMP

(IN

TERNAL

&EX

TERNAL

)

: It is

OTE

possible to rotate the elbow 360oon its vertical axis.

sing the flue clamp, seals and screws supplied

U

The 1 metre horizontal flue kit (3318073) supplied is suitable for an exact

Measure the distance from the face of the external wall to the face of the flue elbow

ubtracted from 815mm, you now have the total amount to be cut from the plain end of the flue.

s

Fig 19)secure the elbow to the boiler.

(

X dimension of 815mm.

(X - Fig 17), this figure must now be

Draw a circle around the outer flue and cut the flue to the required length taking care not to cut the inner flue, next cut the inner
flue ensuring that the length between the inner and outer flue is maintained.

(Fig 19).

e.g.

X = 555mm
815-555 = 260mm (Length to be cut from the plain end of the flue).

Once cut to the required length, ensure that the flue is free from burrs and reassemble the flue. If fitting the flue from inside of the
building attach the grey outer wall seal to the flue terminal and push the flue through the hole, once the wall seal has passed
through the hole, pull the flue back until the seal is flush with the wall. Alternatively, the flue can be installed from outside of the
building, the grey outer seal being fitted last.

12.2 Fitting the 5” Flue (Ø 80 / 125 Horizontal/vertical)

Should the flue require extending, the flue connections are push fit, however, one flue bracket should be used to secure each
metre of flue.

N

OTE:SEE PAGE 24 FOR MAXIMUM AND MINIMUM FLUE RUNS.

Once the boiler has been positioned on the wall, for horizontal flue runs insert the Ø60/100 elbow into the boiler, and connect the
elbow to the Ø80/125 adaptor, for vertival flue runs it is necessary to insert the Ø80/125 adaptor (Fig.20) (not supplied with flue kit

Part No 3318095) into the boiler flue socket.

-

Push the adaptor onto the boilers flue connection, grease the seals then add extensions or elbows as required, secure the
adaptor, using the clamp and screws provided.

To fit extensions or elbows it is first necessary to ensure that the lip seal is fitted correctly into the inner flue, once verified, it is
simply necessary to push them together, no clamps are necessary to secure the flue components.

Before proceeding to fit the flue, ensure that the maximum flue length has not been exceeded (See the tables on Page 24) and
that all elbows and bends have been taken into consideration, the maximum flue length is 10 metres, for each additional 90
1 metre must be subtracted from the total flue length, and for each 45o0.5 metres must be subtracted from the total flue length.

KIT

NOTE: DO

NOT

CUT

THE

VERTICAL

FLUE

.

o

elbow

20