Ariston microSYSTEM Installation Instructions

Installation
Instructions
Type C Boilers

G.C.N: 41-116-06

41-116-07

LEAVE THESE INSTRUCTIONS
WITH THE END-USER

Country of destination: GB/IE

TABLE OF CONTENTS

1. GENERAL INFORMATION

1.1 GENERAL INSTRUCTIONS

1.2 OVERALL VIEW

2. INSTALLATION

2.1 DELIVERY

2.2 REFERENCE STANDARDS

2.3 SITING THE APPLIANCE

2.4 OVERALL DIMENSIONS

2.5 CLEARANCES

2.6 MOUNTING THE APPLIANCE

2.7 ELECTRICAL CONNECTION

2.8 GAS CONNECTION

2.9 WATER CONNECTIONS

2.10 FLUE CONNECTION

2.11 ROOM THERMOSTAT CONNECTION

2.12 ELECTRICAL DIAGRAMS

2.13 GAS AND WATER CIRCUITS

3. D.H.W. STORAGE CYLINDER

3.1 2 PORT AND 3 PORT VALVE INSTALLATIONS

3.2 DOMESTIC HOT WATER PRIORITY KIT

4. COMMISSIONING

4.1 INITIAL PREPARATION

4.2 CONTROL PANEL

4.3 REMOVING THE FRONT PANEL

4.4 INITIAL START UP

4.5 OPERATIONAL ADJUSTMENTS

4.6 COMBUSTION ANALYSIS

4.7 FUME DISCHARGE MONITORING

4.8 DRAINING THE SYSTEM

5. GAS ADJUSTMENTS

GAS ADJUSTMENT TABLE

5.1 CHANGING THE TYPE OF GAS

6. MAINTENANCE

7. TECHNICAL INFORMATION

2

1. GENERAL

User’s
Manual

INFORMATION

This manual is an integral and essential part of the product. It should be kept
with the appliance so that it can be consulted by the user and our authorised
personnel.

Please carefully read the
instructions and notices about the
unit contained in this manual, as
they provide important information
regarding the safe installation, use
and maintenance of the product.

For operating instructions please
consult the separate User’s Manual.

1.1 GENERAL INSTRUCTIONS

Read the instructions and recommendations in these Installation Instructions
carefully to ensure proper installation, use and maintenance of the
appliance.

Keep this manual in a safe place. You may need it for your own reference
while our Servicing Centre technicians or your installer may need to consult
it in the future.

This is an appliance for the production of central heating (C.H.).

This appliance must be used only for the purpose for which it is designed.
The manufacturer declines all liability for damage caused by improper or
negligent use.

No asbestos or other hazardous materials have been used in the fabrication
of this product.

Before connecting the appliance, check that the information shown on the
data plate and the table in section 7 comply with the electric, water and gas
mains of the property.You will find the data plate on the reverse of the control
panel.
The gas with which this appliance operates is also shown on the label at the
bottom of the boiler.

Do not install this appliance in a damp environment or close to equipment
which spray water or other liquids.

Do not place objects on the appliance.
Do not allow children or inexperienced persons to use the appliance without

supervision.

If you smell gas in the room, do not turn on light switches, use the
telephone or any other object which might cause sparks.
Open doors and windows immediately to ventilate the room.
Shut the gas mains tap (at or adjacent to the gas meter) or the valve of the
gas cylinder and call your Gas Supplier immediately.
If you are going away for a long period of time, remember to shut the mains
gas tap or the gas cylinder valve.

Always disconnect the appliance either by unplugging it from the mains or
turning off the mains switch before cleaning the appliance or carrying out
maintenance.

In the case of faults or failure, switch off the appliance and turn off the gas
tap. Do not tamper with the appliance.
For repairs, call your local Authorised Servicing Centre and request the use
of original spare parts. For in-guarantee repairs contact MTS.

Check the following at least once a year:

1 - Check the seals for the water connections; replace any faulty seals.
2 - Check the gas seals; replace any faulty gas seals.
3 - Visual check of the entire unit.

3

4 - Visual check of the combustion process or analysis of combustion by-

products (see section 4.5) and cleaning of the burner if needed.

5 - If called for by point. 3, dismantling and cleaning of the combustion

chamber.
6 - If called for by point. 4, dismantling and cleaning of the burner jets.
7 - Visual check of the primary heat exchanger:

- check for overheating in the blade assembly;

- clean the exhaust fan if needed.

8 - Adjustment of the flow rate of the gas: flow rate for lighting, partial load

and full load.
9 - Check of the heating safety systems:

- safety device for maximum temperature (overheat thermostat);

- safety device for maximum pressure (safety valve).

10- Check of the gas safety systems:

- safety device for lack of gas or flame ionisation (detection
electrode);

- safety device for gas cock.

11- Check of the electrical connection (make sure it complies with the

instructions in the manual).

12- General check of the combustion by-products of the

discharge/ventilation system.

13- Check of the general performance of the unit.

FIG. 1.0

1.2 OVERALL VIEW

LEGEND:

1. Flue connector

2. Air intake for twin pipe flue systems

3. Fan

4. Combustion chamber hood

5. Main heat exchanger

6. Safety thermostat

7. Combustion chamber

8. Combustion chamber insulation panel

9. Detection electrode

10. Ignition electrodes

11. Burner

12. Regulation thermostat

13. Frost thermostat

14. Pump pressure switch

15. Safety valve (3 bar)

16. Automatic By-pass

17. Gas valve

18. Spark generator

19. Boiler drain valve

20. Circulation pump with automatic air release valve

21. Expansion vessel

22. Air pressure take-off point

23. Air pressure switch

24. Combustion analysis points

4

2. INSTALLATION

The technical information and instructions provided herein below are
intended for the installer / Servicing Technician so that the unit may be
installed and serviced correctly and safely.

2.1 DELIVERY

2.2 REFERENCE STANDARDS

There will be two items:
1 - The fully assembled boiler
2 - A separately boxed connection ki

WATER REGULATIONS

In GB it is necessary to comply with the Water Supply (Water Fittings)
Regulations 1999, for Scotland, The Water Bylaws 2000, Scotland. The Genus
30 Plus is an approved product under the Water Regulations.

To comply with the Water Regulations, you attention is drawn to The Water
Regulations guide published by the Water Regulations Advisory Scheme
(WRAS) gives full details of the requirements.

In IE, the requirements given in the current edition of I.S.813 and the current
Building Regulations must be followed.

The installation of this appliance must be in accordance with the relevant
requirements of the Local Building Regulations, the current I.E.E. Wiring
Regulations, the bylaws 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, the Local Building
Regulations (IE).

C.O.S.H.H.

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

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

BS 7593 Treatment of water in domestic hot water central heating

systems
BS 5546 Installation of hot water supplies for domestic purposes
BS 5440-1 Flues
BS 5440-2 Air supply
BS 5449 Forced circulation hot water systems
BS 6798 Installation of gas fired hot water boilers of rated input not

exceeding 60kW
BS 6891 Installation of low pressure gas pipe up to 28mm
BS 7671 IEE wiring regulations
BS 7074 Specification for expansion vessels
BS 5482 Installation of L.P.G.

and in the Republic of Ireland in accordance with the following Codes of
Practice:

I.S. 813 Domestic Gas Installations

The following BS Standards give valuable information;

BS 5546 Installation of hot water supplies for domestic purposes
BS 5449 Forced circulation hot water systems
BS 7074 Specification for expansion vessels
BS 7593 Treatment of water in domestic hot water central heating

systems

5

WARNING!!

The addition of anything that may interfere with the normal operation of the
appliance without express written permission of the manufacturer or his
agent could invalidate the warranty. In GB this could also infringe the GAS
SAFETY(Installation and Use) REGULATIONS.

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.

2.3 SITING THE APPLIANCE

The appliance may be installed in any room or indoor area, although
particular attention is drawn to the requirements of the current I.E.E. Wiring
Regulations, in Scotland, the electrical provisions of the Building
Regulations applicable in Scotland, and in the Republic of Ireland, the
current edition of I.S.813, with respect to the installation of the combined
appliance in a room containing a bath or shower. The location of the boiler in
a room containing a bath or shower should only be considered if there is no
alternative.

Where a room-sealed appliance is installed in a room containing a bath
or shower reference should be made to the relevant requirements.

In GB this is the current I.E.E. WIRING REGULATIONS and BUILDING
REGULATIONS. In IE reference should be made to the current edition
of I.S.813 and the current ETCI rules.

If the boiler is to be sited into a timber framed building, reference must be
made to the current edition of the Institution of Gas Engineers Publication
IGE/UP/7 (Gas Installations in Timber Framed Housing).

The location must permit adequate space for servicing and air circulation
around the appliance as indicated in Section 2.5.
The location must permit the provision of an adequate flue and termination.
For unusual locations special procedures may be necessary.
BS 6798-1987 gives detailed guidance on this aspect.
A compartment used to enclose the appliance must be designed specifically
for this purpose. No specific ventilation requirements are needed for the
installation within a cupboard.

This appliance is not suitable for outdoor installation.

The type C appliances (in which the combustion circuit, air vent intake
and combustion chamber are air-tight with respect to the room in
which the appliance is installed) can be installed in any type of room.

Secondary ventilation is not required with this boiler. The boiler must be
installed on a solid, non-combustible, permanent wall to prevent access from
the rear.

6

E

L

N

132 132

C

E

400 mm

300 mm

60 mm

450 mm

FIG. 2.1

2.4 OVERALL DIMENSIONS

LEGEND:

A = Central Heating Flow (3/4”)
C = Gas Inlet (3/4”)
E = Central Heating Return (3/4”)
mm = Clearances

2.5 CLEARANCES

In order to allow for access to the interior of the boiler for
maintenance purposes, the boiler must be installed in
compliance with the minimum clearances indicated in FIG. 2.1

2.6 MOUNTING THE APPLIANCE

Fasten the boiler in place using the template and anchors
supplied with the unit. It is highly recommended that a
spirit level be used to position the boiler so that it is
perfectly level.
For additional information, please consult the instructions
contained in the connection kit and the flue kit.

FIG. 2.2

2.7 ELECTRICAL CONNECTION

For safety purposes, have a competent person carefully
check the electrical system in the property, as the
manufacturer will not be held liable for damage caused by
the failure to earth the appliance properly or by anomalies
in the supply of power. Make sure that the residential
electrical system is adequate for the maximum power
absorbed by the unit, which is indicated on the rating plate.
In addition, check that the section of cabling is appropriate
for the power absorbed by the boiler.

The boiler operates with alternating current, as indicated in
the technical information table in section 7, where the
maximum absorbed power is also indicated. Make sure
that the connections for the neutral and live wires
correspond to the indications in the diagram. The
appliance electrical connections are situated on the
reverse of the control panel under the inspection cover
(see the servicing manual for further information)

IMPORTANT!

In the event that the power supply cord must be changed,
replace it with one with the same specifications. Make the
connections to the terminal board located within the
control panel, as follows:

- The yellow-green wire should be connected to the
terminal marked with the “”symbol;

- The blue wire should be connected to the terminal
marked “N”;

- The brown wire should be connected to the terminal

7

marked “L”.
Note: The diagrams for the electrical system are indicated in section 2.12.

Warning, this appliance must be earthed.

External wiring must be correctly earthed, polarised and in accordance with
relevant regulations / rules. In GB this is the current I.E.E. WIRING
REGULATIONS. In IE reference should be made to the current edition of the
ETCI rules. This boiler is supplied for connection to a 220 - 240 V~ 50 Hz
supply.

The supply must be fused at 3 A.

The method of connection to the electricity supply must facilitate complete
electrical isolation of the appliance, by the use of a fused double pole
isolator having a contact separation of at least 3 mm in all poles or
alternatively, by means of a 3 A fused three pin plug and unswitched
shuttered socket outlet both complying with BS 1363.
The point of connection to the Electricity supply must be readily accessible
and adjacent to the appliance unless the appliance is installed in a bathroom
when this must be sited outside the bathroom (see section 2.3).

2.8 GAS CONNECTION

2.9 WATER CONNECTIONS

FIG. 2.4

The local gas region contractor connects the gas meter to the service pipe.
The gas installation should be in accordance with the relevant standards. In
GB this is BS6891 and in IE this is the current edition of I.S.813. The
connection the the appliance is a 22mm copper tail located at the rear of the
gas service cock (FIG. 2.3). If the gas supply for the boiler serves other
appliances ensure that an adequate supply is available both to the boiler
and the other appliances when they are in use at the same time. Pipe work
must be of an adequate size. Pipes of a smaller size than the boiler inlet
connection should not be used.

VIEW OF THE BOILER CONNECTIONS

G

F

A

C

E

FIG. 2.3

LEGEND:

A = Central Heating Flow
C = Gas Inlet
E = Central Heating Return
F = Safety Valve
G = Pump transportation screw

(remove before igniting the boiler)

H = Automatic By-pass pipe

8

H

SC004A

CENTRAL HEATING

Detailed recommendations are given in BS 6798:1987 and BS 5449-1:1990,

the following notes are given for general guidance.

PIPE WORK

Copper tubing to BS EN 1057:1996 is recommended for water pipes.
Jointing should be either with capillary soldered or compression fittings.
Where possible pipes should have a gradient to ensure air is carried
naturally to air release points and water flows naturally to drain taps.
The appliance has a built-in automatic air release valve, however it
should be ensured as far as possible that the appliance heat exchanger
is not a natural collecting point for air.
Except where providing useful heat, pipes should be insulated to prevent
heat loss and avoid freezing.
Particular attention should be paid to pipes passing through ventilated
spaces in roofs and under floors.

BY-PASS

The appliance includes an automatic by-pass valve, which protects the
main heat exchanger in case of reduced or interrupted water circulation
through the heating system, due to the closing of thermostatic valves or
cock-type valves within the system.

SYSTEM DESIGN

This boiler is suitable only for sealed systems.

DRAIN COCKS

These must be located in accessible positions to permit the draining of
the whole system. The taps must be at least 15mm nominal size an
manufactured in accordance with BS 2870:1980.

SAFETY VALVE DISCHARGE (PRIMARY WATER)

The discharge should terminate facing downwards on the exterior of the
building in a position where discharging (possibly boiling water & steam)
will not create danger or nuisance, but in an easily visible position, and
not cause damage to electrical components and wiring.
The discharge must not be over an entrance or a window or any other
type of public access.

MAINS WATER FEED - CENTRAL HEATING

There must be no direct connection to the mains water supply even
through a non-return valve, without the approval of the Local Water
Authority, and must be in accordance with water supply regulations. Your
attention is drawn to, for GB: Guidance G24.2 and recommendation
R24.2 of the water regulations guide and for IE: the current edition of
I.S.813.

FILLING

A temporary method for initially filling the system and replacing lost water
during servicing and initial filling (complying to current water regulations
and byelaws) is provided. The flexible hose must be removed once the
system has been filled.

RESIDUAL HEAD OF THE BOILER

9

2.10 FLUE CONNECTIONS

FLUE SYSTEM

The provision for satisfactory flue termination must be made as described in
BS 5440-1, for IE recommendations I.S.813.
The appliance must be installed so that the flue terminal is exposed to
outdoor air, consideration must be given to terminal discharges onto a
pathway or passageway, check that the combustion discharges will not
cause a nuisance and that the terminal will not obstruct the passageway.
The terminal must not discharge into another room or space such as an
outhouse or lean-to.
It is important that the position of the terminal allows a free passage of air
across it at all times.
If the terminal is fitted within 1 metre of a plastic gutter, within 500mm of a
painted eave or a painted gutter, an aluminium shield of at least 1 metre
long should be fitted to the underside of the gutter or painted surface. An air
space of 5mm should be left between shield and gutter.
The terminal should be located with due regard for the damage or
discolouration that might occur on buildings in the vicinity.
In cold or humid weather water vapour may condense on leaving the flue
terminal. The effect of such “steaming” must be considered.
If the terminal is less than 2 metres above a balcony, above ground or above
a flat roof to which people have access, then a suitable terminal guard must
be fitted. When ordering a terminal guard, quote the appliance model
number.

A suitable terminal guard is available from:

TOWER FLUE COMPONENTS
Morley Road
Tonbridge
Kent TN9 1RA

The minimum acceptable spacing from the terminal to obstructions and
ventilation openings are specified in FIG. 2.5.

FIG. 2.5

Ø 60/100 mm

T

ERMINALPOSITION

A - Directly above or below an openable window

or other opening 300
B - Below gutters, solid pipes or drain pipes 75
C - Below eaves 200
D - Below balconies or car-port roof 200
E - From vertical drain pipes and soil pipes 150
F - From internal or external corners 300
G - Above ground or balcony level 300
H - From a surface facing a terminal 600

I - From a terminal facing a terminal 1200

J - From an opening in the car port

(e.g. door, window) into dwelling 1200
K - Vertically from a terminal in the same wall 1500
L - Horizontally from a terminal in the same wall 300
M - Horizontally from an opening window 300
N - Fixed by vertical flue terminal

mm

The boiler is designed to be connected to a coaxial flue discharge system.

FIG. 2.6

10

In addition, it is also possible to use a split (twin pipe)
system by fitting a special adaptor to the flue connector
and using the aperture for the air vent intake located on
the top part of the combustion chamber.
To utilise the air intake it is necessary to:

1. Remove the bottom of the air intake by cutting it with a
suitable knife (see FIG. 2.7);

2. Insert the elbow into the air intake until it reaches the
lower end. (There is no need to use gaskets or sealing
compounds).

FIG. 2.7

FIG. 2.8

COAXIAL SYSTEMS

Ø 80 mm

IMPORTANT!

For all flue systems, a restrictor
must always be inserted into the
boiler’s flue connector; the
restrictor must be Ø 46 or Ø 41 in
diameter depending on the length
of piping indicated in TABLE 2.1.

FIG 2.9 and FIG 2.10 illustrate some

of the various designs for coaxial or
twin pipe flue systems.
For further information on
discharge/ventilation accessories,
see the FLUE P IPE ACCESSORIES

MANUAL.

FIG. 2.9

11

21 RFFI

Exhaust

Type

Restrictor

ø 46 mm

Maximum
Extension
Exhaust/Air

Risk of Condensation Forming

Piping not insulated

ø 46 restrictor NO restrictor

TABLE 2.1

Piping insulated

ø 46 restrictor NO restrictor

Coaxial

Systems

ø 60/100

28 RFFI

Coaxial

Systems

ø 60/100

21 RFFI

Twin Pipe

Systems

ø 80/80

C12 (xx)
C32 (xx)
C42 (xx)

Exhaust

Type

C12 (xx)
C32 (xx)
C42 (xx)

Exhaust

Type

C12 (xy)
C32 (xy)
C42 (xy)

C52 (xy)
C82 (xy)

L min = 0.5 m

L max = 1 m

Restrictor

ø 41 mm

L min = 0.5 m

L max = 1 m

Restrictor

ø 46 mm

L max = 25 m

L max = 22 m

L = 4 m

Maximum
Extension
Exhaust/Air

L = 4 m

Maximum
Extension
Exhaust/Air

34 m
34 m
34 m

31 m

NONE NONE

Risk of Condensation Forming

Piping not insulated

ø 41 restrictor NO restrictor

NONE NONE

Risk of Condensation Forming

Piping not insulated

ø 46 restrictor NO restrictor

3.0 m 4.5 m

3.3 m 4.8 m

NONE NONE

Piping insulated

ø 41 restrictor NO restrictor

NONE NONE

Piping insulated

ø 46 restrictor NO restrictor

12.5 m 16.0 m

14.0 m 17.8 m

28 RFFI

Twin Pipe

Systems

ø 80/80

TWIN PIPE

SYSTEMS

FIG. 2.10

Exhaust

Type

C12 (xy)
C32 (xy)
C42 (xy)

C52 (xy)
C82 (xy)

Restrictor

ø 41 mm

L max = 38 m

L max = 34 m

Maximum
Extension
Exhaust/Air

62 m
62 m
62 m

54 m

Risk of Condensation Forming

Piping not insulated

ø 41 restrictor NO restrictor

8 m 11 m

8 m 11 m

Piping insulated

ø 41 restrictor NO restrictor

19 m 31 m

19 m 31 m

L = Sum of the total length of exhaust + air intake piping.

In calculating the lengths of the pipes, the
maximum length “L” must also take into
consideration the values for the
exhaust/air intake end terminals, as well
as 90° elbows for coaxial systems.
The C52 types must comply with the

following requirements:

1 - The exhaust/ air intake pipes must

have the same diameter of

2 - If elbows are to be inserted into the

air intake and/or exhaust system, the
calculation of the overall length must
take into consideration the values for
each elbow, see the FLUE P IPE
ACCESSORIES MANUAL.

3 - The exhaust pipe must protrude by at

least 0.5 m above the top of the roof
in the event that it is located on the
opposite side of the building to the
side with the air intake (this condition
is not obligatory when the air intake
and exhaust are located on the same
side of the building).

ø 80 mm.

12

2.11 ROOM THERMOSTAT
CONNECTION

To connect a room thermostat and/or time clock, it is necessary to:

1. - Open the control panel as indicated in section 4.3;

2.- Remove screws “A” and remove the inspection cover from the reverse of the control
panel;

3. - For the room-thermostat connect the thermostat switching wires to the position 5 and
6 and remove the wire link (for three-wire thermostats connect the neutral to terminal
N);

4. - For the time clock connect the clock switching wires to the positions 3 and 4 and
connect the clock motor electrical supply to the terminals marked L and N.

Note: A frost thermostat is built-in to the appliance.

For connection to control systems with zone valves for hot water cylinders
see section 3.

A

13

2.12 ELECTRICAL DIAGRAM

LEGEND:

A - On/Off Switch
B - On/Off L.E.D.
C - Heating Switch
D - Heating L.E.D.
E - Reset Button
F - Ignition Failure (Lockout) L.E.D.

A01 - Pump Pressure Switch
A02 - Frost Thermostat
A03 - Modulator
A04 - Circulation Pump
A05 - Regulation Thermostat
A06 - External Control System
A07 - Time Clock Connector
A08 - External (Room) Thermostat
A09 - Air Pressure Switch
A10 - Fan

A11 - Overheat Thermostat
A12 - Spark Generator/Gas Valve Supply
A13 - Detection Electrode

Colours:
Wh -White
Bl -Blue
Gry -Grey
Brn -Brown
Blk -Black
Rd -Red
Grn/Yll -Yellow/Green

FIG. 2.12

14

1

2

3

4

5
6

7

8
9

10

11

12

13

14

15

16

17

FIG. 2.13

2.13 GAS AND WATER CIRCUITS

FIG. 2.14

LEGEND:

1. Fan

2. Main heat exchanger

3. Overheat thermostat

4. Burner

5. Ignition electrodes

6. Detection electrode

7. Regulation thermostat

8. Frost thermostat

9. Gas valve

10. Pump pressure switch

11. Safety valve (3 bar)

12. Boiler drain valve

13. Automatic by-pass

14. Pressure gauge

15. Circulation pump with automatic
air release valve

16. Expansion vessel

17. Air pressure switch

A. Central Heating Flow
C. Inlet Gas
E. Central Heating Return

15

3. D.H.W. STORAGE
CYLINDER

3.1 2 PORT AND 3 PORT VALVE
INSTALLATIONS

The microSYSTEM can be connected to a storage cylinder (both open-vented and
unvented) for the production of domestic hot water (D.H.W.). Cylinders of different
capacities can be used depending on site requirements (see TABLE 3.1 for a
selection of ARISTON unvented cylinders).

2 port valve installation

FIG. 3.1

3 port valve installation

FIG. 3.2

FIG. 3.3

Wiring to 2 port valve installation
using an external 2 channel
programmer
Type Danfoss FP715
Type Honeywell ST6400C

16

Technical Data Capacity Coil C.H.W. D.H.W. Max Heating Heat Ioss

Surface Flow/rate Flow/rate Output

MODEL It. m

2

m3/h It/h kW kWh/24h

Contract STI 125 Indirect 125 0.75 0.5 194 11.3 2

1 266 15.5
2 340 19.8

Comfort STI 125 Indirect 125 0.75 0.5 256 14.9 2.2
Contract STI 150 Indirect 150 0.93 1 353 20.5

2 451 26.2

Comfort STI 150 Indirect 150 0.93 0.5 256 14.9 2.4
Contract STI 210 indirect 200 0.93 1 353 20.5

2 451 26.2

Comfort STI 210 Indirect 200 0.93 0.5 256 14.9 2.9
Contract STI 300 Indirect 300 0.93 1 353 20.5

2 451 26.2

SB 125 Indirect 125 1 0.5 190 11 1.72

1 318 18.5
2 496 28.8

SB 150 Indirect 150 1 0.5 190 11 1.75

1 318 18.5
2 496 28.8

SB 200 Indirect 200 1.3 0.5 190 11 2.1

1 318 18.5
2 496 28.8

Wiring to 3 port valve installation
using an external 2 channel
programmer
Type Danfoss FP715
Type Honeywell ST6400C

FIG. 3.4

NOTE: When using a 3 port valve installation in conjunction with an unvented cylinder it

will be necessary to use a 2 port valve on the cylinder flow connection in addition
to the 3- port valve to satisfy Building Regulations.

TABLE 3.1

17

3.2 DOMESTIC HOT WATER
PRIORITY KIT

Boiler microSYSTEM microSYSTEM

21 RFFI 28 RFFI

Cylinder

Contract STI 125 Indirect

Comfort STI 125 Indirect

Contract STI 150 Indirect

Comfort STI 150 Indirect

Contract STI 210 Indirect

Comfort STI 210 Indirect

Contract STI 300 Indirect

SB 125 Indirect

SB 150 Indirect

SB 200 Indirect

TABLE 3.2

4. COMMISSIONING

The microSYSTEM is able to be connected to a specially designed
kit for the management of D.H.W. production. This kit gives priority to
production of D.H.W. unlike traditional systems where the boiler
power is split between C.H. and D.H.W. This generally enables a
smaller storage cylinder to be chosen as the boiler’s full output will be
channelled into the cylinder allowing for a quick heat-up.

The kit (ARISTON part number 706329) can be obtained from an
ARISTON supplier.

The kit consits of:

1) Electronic module able to plug into the boiler’s P.C.B;

2) 3-way priority valve with actuator for connection to the boiler’s
flow outlet;

3) A limit thermostat (80˚C) to check the water temperature of the
heating flow to the cylinder, to be installed within the boiler;

4) Pipes and accessories.

= Ideal

= Possible

MTS support the initiative. Within the information pack you will find
a copy of the Log Book. It is important that this is completed in the
presence of your customer, they are shown how to use it, and it is signed by
them. Please instruct your customer that they must have their Log
Book with them whenever they contact a service engineer or us.

4.1 INITIAL PREPARATION

Preliminary electrical system checks to ensure electrical safety must be
carried out by a competent person i.e. polarity, earth continuity, resistance to
earth and short circuit.

FILLING THE HEATING SYSTEM:

Remove the panels of the case and lower the control panel (see section

3.3 for further information).
Open the central heating flow and return cocks supplied with the
connection kit (there are two isolation points on the return connection).
Unscrew the cap on the automatic air release valve one full turn and leave
open permanently.
Close all air release valves on the central heating system.
Gradually open valve(s) at the filling point (filling-loop) connection to the
central heating system until water is heard to flow, do not open fully.
Open each air release tap starting with the lowest point and close it only
when clear water, free of air, is visible.

Purge the air from the pump by unscrewing anticlockwise and
removing the pump plug and also manually rotate the pump shaft in
the direction indicated by the pump label to ensure the pump is free.

Refit the pump plug.
Continue filling the system until at least 1.5 bar registers on the pressure
gauge.
Inspect the system for water leaks and remedy any leaks discovered.

GAS SUPPLY:

Inspect the entire installation including the gas meter and test for
soundness. The gas installation should be in accordance with the relevant
standards. In GB this is BS6891 and in IE this is the current edition of
I.S.813.

18

A

B
C
D
E
F

IL

GH

If the gas supply for the boiler serves other appliances ensure that an
adequate supply is available both to the boiler and the other appliances
when they are in use at the same time.
Pipe work must be of an adequate size. Pipes less than the 22mm should
not be used.
Open the gas cock (supplied with the connection kit) to the appliance and
check the gas connections on the appliance for leaks.
When the installation and filling are completed, flush the system while cold,
refill, turn on the Central Heating system (Section 4.4) and run it until the
temperature has reached the boiler operating temperature.
The system must then be immediately flushed through.
The flushing procedure must be in line with BS 7593:1992 code of practice
for treatment of water in domestic hot water central heating systems.

During this operation, we highly recommend the use of a central heating
flushing detergent (Fernox Superfloc or equivalent), whose function is to
dissolve any foreign matter that may be in the system.

Substances different from these could create serious problems to the
pump or other components.

The use of an inhibitor in the system such as Fernox MB-1 or equivalent is
strongly recommended to prevent corrosion (
system.

Failure to carry out this procedure may invalidate the appliance
warranty.

sludge) damaging the boiler and

For IE it is necessary to complete a “Declaration of Conformity” to indicate
compliance to I.S.813. An example of this is given in the current edition of
I.S.813. In addition it is necessary to complete the “Benchmark” Log Book.

4.2 CONTROL PANEL

LEGEND:

A - On/Off button
B - On/Off L.E.D. green (frost protection active)
C - Central Heating button
D - Cental Heating active L.E.D. green
E - Ignition failure (lockout) and/or overheat reset button
F - Ignition failure (lockout) and/or overheat L.E.D. red
G - Central heating temperature adjustment
H - Energy Saving System (ESS)
I - Knock-out for time clock
J - Heating system pressure gauge

4.3 REMOVING THE
FRONT PANEL

FIG. 4.1

1

A

In order to access the inside of the boiler, it is necessary to
unscrew the fastening screws “A” of the control panel
located on the lower part of the panel itself.
The control panel moves downward and when pulled
forward rotates on two lateral hinges.
The panel stays in a semi-horizontal position, which allows
access to the inner parts of the boiler.
In order to increase the manoeuvring space, it is possible
to raise the control panel and rotate it to a fully horizontal
position.

19

2

3

4

B

To dismantle the front casing panel it is necessary to:
1 - Remove the two screws “B”;
2 - Move the front casing panel up and lift forward.

4.4 INITIAL STA RT-UP

THE CHECKS TO BE RUN BEFORE INITIAL START-UP ARE AS FOLLOWS:

1. Make sure that:

-the screw on the automatic air valve has been loosened when the
system is full;

- If the water pressure in the system is below 1.5 bar, bring it up to the
appropriate level;

- Ensure that the gas cock is closed;

- Make sure that the electrical connection has been made properly and
that the earth wire is connected to an efficient earthing system;

- Supply power to the boiler by pushing the On/Off button “A” (see
FIG.4.1) - the L.E.D. “B” will illuminate. Then push the button “C” in for
central heating - the L.E.D. “D” will illuminate. This will start the
circulation pump. After 7 seconds, the boiler will signal a shutdown due
to ignition failure. Leave the boiler as it is until all of the air has been bled
from the system.

- Loosen the cap on the head of the pump to eliminate any air pockets;

- Repeat the procedure for bleeding the radiators of air;

- Check the system pressure and, if it has dropped, open the filling loop
again to bring the pressure back up to 1.5 bar.

2. Make sure that all gate valves are open;

3. Turn on the gas cock and check the seals on the connections with an
approved soap solution and eliminate any leaks.

4. Press the reset button “E” for the lighting system; the spark will light the
main burner. If the burner does not light the first time, repeat the
procedure.

5. Check the minimum and maximum pressure values for the gas going to
the burner; adjust it if needed using the values indicated in the table in
section 5 (See the relative section for burner pressure adjustment within
the servicing manual).

5

20

4.5 COMBUSTION ANALYSIS

FIG. 4.2

4.6 FUME DISCHARGE
MONITORING

In the boiler, it is possible to monitor the correct operation of
the flue exhaust/air intake, checking for a loss of general
pressure in the system. Through the use of a differential
manometer connected to the test points of the combustion
chamber, it is possible to detect the ∆P of operation of the air
pressure switch.
The value detected should not be less than 0.55 mbar under
conditions of maximum thermal power in order for the boiler
to function properly and without interruption.

The flue connector has two apertures, readings can be

taken for the temperature of the combustion by-products
and of the combustion air, as well as of the concentrations
of O2and CO2, etc. .

To access these intakes it is necessary to unscrew the front
screw and remove the metal plate with sealing gasket.
To achieve the best test conditions, turn the central heating
adjustment knob “G” to the “max” position and remove the
electrical connection to the heating sensor (see section 6.).
This will allow the appliance to operate at the maximum
heating power.

FIG. 4.3

4.7 BOILER SAFETY SYSTEMS

The boiler is fitted with the following devices (see section 4.2 for references).

1 - IGNITION FAILURE:

This indicates ignition failure when a flame is not detected within 7
seconds of starting an ignition sequence. The L.E.D. “F” will illuminate
to signal the shutdown status.
The system can be reset by pressing and releasing the button “E” after
checking to make sure that the gas cock is open.

2 - INSUFFICIENT SYSTEM PRESSURE:

In the event of insufficient water pressure in the heating system, a
safety device will shutdown the boiler. Check the system pressure on
the pressure gauge “J” and if it is less than 0.4 bar refill the system to

1.5 bar. Once the system pressure is at the correct level the boiler will
ignite automatically.

3 - OVERHEATING:

This control shuts off the boiler in the case where the primary circuit
reaches a temperature in excess of 105°C.
The red L.E.D. “F” will illuminate to signal this shutdown status.
The system can be reset by waiting a few minutes for the primary
exchanger to cool down and then by pressing and releasing the “E”
button.

4. ANTI-FROST DEVICE:
The boiler is equipped with a device that, in the event of the water
temperature going below 6°C, the burner ignites at the minimum power
until the boiler water reaches a temperature of 16°C.
This device operates only if the boiler is functioning perfectly and:

- the system pressure is sufficient;

- the boiler is powered electrically - L.E.D.

- the gas is turned on.

5 - EXHAUST DISCHARGE ANOMALY SHUTDOWN:

The boiler is fitted with safety devices, which in the event of defective
discharge of exhaust fumes, automatically interrupts the gas supply,
thereby shutting off the boiler.
The shutdown of the boiler is temporary and when the discharge state
of exhaust fumes has returned to normal, the boiler automatically turns
back on

21

“B” illuminated;

4.8 DRAINING THE SYSTEM

The heating system must be emptied as follows:

- Turn off the boiler;

- Attach a hose pipe and open the drain valve;

- Empty the system at the lowest points (where present). When the heating
system is unused for an extended period of time, it is recommended that you
add antifreeze with an ethylene glycol base to the water in the
heating lines and radiators if the ambient temperature drops below 0°C during
the winter.
This makes repeated draining of the entire system unnecessary.

5. GAS ADJUSTMENTS

CATEGORY II2H3+

Lower Wobbe Index (15°C;1013mbar) MJ/m3h
Nominal Delivery Pressure mbar
Minimum Delivery Pressure mbar

21 RFFI

Main Burner: n. 12 jets (ø) mm
Consumption (15°C; 1013mbar) m
Consumption (15°C; 1013mbar) Kg/h
Gas Burner Pressure:
max - min mbar

28 RFFI

Main Burner: n. 14 jets (ø)
Consumption (15°C; 1013mbar) m3/h
Consumption (15°C; 1013mbar) Kg/h
Gas Burner Pressure:
max - min mbar

3

/h

Methane Gas

G20

45.67
20
17

1.30

2.4 - 1.05

----

8.5 - 1.7

1.30

3.15 -1.26

----

11.0 - 1.6

Liquid Butane Gas

G30

80.58
29
20

0.77

----

1.78 - 0.78

27.5 - 6.2

0.77

----

1.78 - 0.78

27.7 - 4.6

TABLE 5.1

Liquid Propane Gas

G31

80.58
37
25

0.77

----

1.76 - 0.77

37.4 - 8.0

0.77

----

1.76 - 0.77

35.5 - 6.0

[1 mbar = 10,197 mmc.a.]

5.1 CHANGING THE
TYPE OF GAS

The outlet pressure of the gas cock is obtained by completely loosening the
screw on the solenoid. The maximum pressure of the gas to the burner will
be equal to the nominal delivery pressure minus the head loss within the
gas valve.

The boiler can be converted to use either methane (natural) gas (G20)
or LPG (G30 - G31) by an Authorised Service Centre.

The operations that must be performed are the following:

1. Replace the jets on the main burner (see table in section 5);

2. Adjust the maximum and minimum thermal capacity values for the boiler
(see table in section 5);

3. Replace the gas rating plate;

4. Adjust the maximum thermal power setting;

5. Adjust the soft-light feature (open the cover of the regulation screw on the

gas valve (see FIG. 5.1). Rotate clockwise from min. to max. as per
installation requirements).

22

FIG. 5.1

VG002Ab

6. MAINTENANCE

It is recommended that the following inspections be carried out on the
boiler at least once a year:

1 - Check the seals for the water connections; replace any faulty seals.
2 - Check the gas seals; replace any faulty gas seals.
3 - Visual check of the entire unit.
4 - Visual check of the combustion process or analysis of combustion by-

products (see section 4.5) and cleaning of the burner if needed.

5 - If called for by point. 3, dismantling and cleaning of the combustion

chamber.
6 - If called for by point. 4, dismantling and cleaning of the burner jets.
7 - Visual check of the primary heat exchanger:

- check for overheating in the blade assembly;

- clean the exhaust fan if needed.

8 - Adjustment of the flow rate of the gas: flow rate for lighting, partial load

and full load.
9 - Check of the heating safety systems:

- safety device for maximum temperature (overheat thermostat);

- safety device for maximum pressure (safety valve).

10- Check of the gas safety systems:

- safety device for lack of gas or flame ionisation (detection
electrode);

- safety device for gas cock.

11- Check of the electrical connection (make sure it complies with the

instructions in the manual).

12- General check of the combustion by-products of the

discharge/ventilation system.

13- Check of the general performance of the unit.

23

6. TECHNICAL INFORMATION

CE Certification
Heat Input max/min kW
Heat Output max/min kW
Efficiency of Nominal Heat Input %
Efficiency at 30% of Nominal Heat Input %
Heat Loss to the Casing (∆T=50°C) %
Flue Heat Loss with Burner Operating %
Flue Heat Loss with Burner Off %
Maximum Discharge of Fumes (G20) Kg/h
Residual Discharge Head mbar
Consumption at Nominal Capacity(G20) m
Gas Consumption after 10 Minutes* m

3

/h

3

(15°C, 1013 mbar) (G30-G31) Kg/h
Temp. of exhaust fumes at nominal capacity °C
CO2 Content %

O2 Content %

CO Content ppm
Minimum Ambient Temperature °C
Head Loss on Water Side (max) (∆T=20°C) mbar
Residual Head of System bar
Heating Temperature max/min °C
Expansion Vessel Capacity l
Expansion Vessel Pre-load Pressure bar
Maximum Water Content of System l
Maximum Heating Pressure bar
Nominal Pressure Natural Gas (G20) mbar

LPG (G30-G31) mbar
Electrical Supply (V±5%) V/Hz
Power Consumption W
Protection Grade of Electrical System IP
Internal Fuse Rating
Weight Kg

21 RFFI

63AU4549

22.7/10.0

21.0/8.7

92.8

90.8

1.2

6.0

0.2

46.2

0.70

2.4

0.32/0.39

1.78/1.76

117.2

6.81

9

20
+5

200

0.25

82/42

6
1

130

3

20

30-37

230/50

155

X4D

FAST 2 AT

39

28 RFFI

63AU4549

29.8/12.0

27.8/10.5

93.5

90.7

0.2

6.3

0.4
60

1.60

3.15

0.37

2.34/2.31

128.8

6.9

8.1

48
+5

200

0.25

82/42

6
1

130

3

20

30-37

230/50

155

X4D

FAST 2 AT

39

G.C. Number

*Calculated at 70% maximum output

Manufacturer: Merloni TermoSanitari SpA - Italy

Commercial subsidiaries: MTS (GB) Limited MTS Heating Limited

MTS Building Damastown Industrial Park
Hughenden Avenue Damastown Avenue
High Wycombe Mulhuddart
Bucks HP13 5FT Dublin 15

Telephone: [phone] Telephone: [phone]

Fax: [phone] Fax: [phone]

Internet: www.mtsgroup.com/uk Internet: www.mtsgroup.com/ie

E-mail: [e-mail] E-mail: [e-mail]

Technical Advice: 0870 241 8180 Technical Advice: [phone]

Customer Service: 0870 600 9888 Customer Service: [phone]

41-116-06

41-116-07

23 99 84 1549 000 - Stampa: bieffe RECANATI