
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

2
TABLE OF CONTENTS
1. GENERAL INFORMATION
1.1 G
ENERAL I
NSTRUCTIONS
1.2 O
VERALL V
IEW
2. INSTALLATION
2.1 R
EFERENCE STANDARDS
2.2 SITING THE APPLIANCE
2.3 OVERALL DIMENSIONS
2.4 CLEARANCES
2.5 MOUNTING THE APPLIANCE
2.6 ELECTRICAL CONNECTION
2.7 GAS CONNECTION
2.8 W
ATER CONNECTIONS
2.9 F
LUE CONNECTION
2.10 R
OOM THERMOSTAT CONNECTION
2.11 ELECTRICAL DIAGRAMS
2.12 G
AS 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 I
NITIAL PREPARATION
4.2 C
ONTROL PANEL
4.3 R
EMOVING THE FRONT PANEL
4.4 I
NITIAL 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

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.
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 (GB) Limited.
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.
1. GENERAL
INFORMATION
3
1.1 GENERAL INSTRUCTIONS

4
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.
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
1.2 O
VERALL VIEW
FIG. 1.0

5
The technical information and instructions provided herein below are
intended for the installer so that the unit may be installed correctly and
safely.
The installation and initial start up of the boiler must be by a CORGI
Registered Installer in compliance with the installation standards currently in
effect, as well as with any and all local health and safety standards i.e.
CORGI .
This appliance must be installed by a competent installer in
accordance with current Gas Safety (installation & use)
Regulations.
The installation of this appliance must be in accordance with the relevant
requirements of the current Gas Safety (installation & use) Regulations, the
Local Building Regulations, the current I.E.E. Wiring Regulations, the
byelaws of the local water authority, and in Scotland, in accordance with the
Building Standards (Scotland) Regulation and Health and Safety document
No.635 “Electricity at work regulations 1989”.
Installation should also comply with the following British Standard Codes of
Practice:
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. Wir ing
Regulations, and in Scotland, the electrical provisions of the Building
Regulations applicable in Scotland, with respect to the installation of the
appliance in a room containing a bath or shower.
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 so that it cannot be
touched by a person using the bath or shower.
The location must permit adequate space for servicing and air circulation
around the appliance as indicated in paragraph 2.4.
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, permanent wall to prevent access from the rear.
2.1 REFERENCE STANDARDS
2. INSTALLATION
2.2 SITING THE APPLIANCE
BS 7593:1992 Treatment of water in domestic hot water central
heating systems
BS 5546:1990 Installation of hot water supplies for domestic
purposes
BS 5440-1:1990 Flues
BS 5440-2:1989 Air supply
BS 5449:1990 Forced circulation hot water systems
BS 6789:1987 Installation of gas fired hot water boilers of rated
input not exceeding 60kW
BS 6891:1989 Installation of low pressure gas pipe up to 28mm
BS 7671:1992 IEE wiring regulations
BS 4814:1990 Specification for expansion vessels
BS 5482:1994 Installation of LPG

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
6
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.
2.6 ELECTRICAL CONNECTION
2.5 MOUNTING THE APPLIANCE
LEGEND:
A = Central Heating Flow (3/4”)
C = Gas Inlet (3/4”)
E = Central Heating Return (3/4”)
mm = Clearances
2.3 OVERALL DIMENSIONS
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 F
IG. 2.1
2.4 CLEARANCES
F
IG. 2.1
F
IG. 2.2
132 132
C
400 mm
60 mm
450 mm
E
300 mm
N
L
E

VIEW OF THE BOILER CONNECTIONS
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
CENTRAL HEATING
Detailed recommendations are given in BS 6798:1987 and BS 5449-1:1990,
the following notes are given for general guidance.
2.8 WATER CONNECTIONS
2.7 GAS CONNECTION
The local gas region contractor connects the gas meter to the service pipe.
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.
7
marked “L”.
Note:The diagrams f or the electrical system are indicated in section 2.12.
Warning,this appliance must be earthed.
External wiring to the appliance must be carried out by a competent person
and be in accordance with the current I.E.E. Regulations and applicable
local regulations. The microSYSTEM range of boilers are supplied for
connection to a 230 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 2.2).
FIG. 2.3
F
IG. 2.4
F
A
D
B
C
E
SC004A

8
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.
B
Y-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 radiator
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 and should be fitted at all low points.The taps must be at least
15mm nominal size and manufactured in accordance with BS 2870:1980.
S
AFETY VALVE DISCHARGE:
The discharge should terminate facing downward 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.
A
IR RELEASE
POINTS:
These must be fitted at all high points where air naturally collects and must
be sited to facilitate complete filling of the system.
The appliance has an integral sealed expansion vessel to accommodate the
increase of water volume when the system is heated.
It can accept up to 6 litre (1.3 gal) of expansion water. If the heating circuit
has an unusually high water content, calculate the total expansion and add
an additional sealed expansion vessel with adequate capacity. This should
be located on the return pipe work as close as possible to the pump inlet.
M
AINS 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.
F
ILLING:
A temporary method for initially filling the system and replacing lost water
during servicing and initial filling (in accordance with current Water
Regulations), is provided as an integral part of the connection kit (see F
IG.
2.4).The flexible hose must be removed once the system has been filled.
RESIDUAL HEAD OF THE BOILER

The boiler is designed to be connected to a coaxial flue discharge system.
9
2.9 FLUE CONNECTIONS
FLUE
SYSTEM
The provision for satisfactory flue ter mination must be made in accordance
with BS 5440-1.
The appliance must be installed so that the flue terminal is exposed to outside air.
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.
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 “pluming”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 ter minal 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 F
IG. 2.5.
T
ERMINALPOSITION
mm
A - Directly below an openable window or other opening 300
B - Below gutters, soil 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 75
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
FIG. 2.5
HI
BC
F
D
J
A
E
F
G
K
L
G

Ø 80 mm
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 F
IG. 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).
10
I
MPORTANT
!
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 inT
ABLE 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 F
LUE PIPE ACCESSORIES
MANUAL.
COAXIAL SYSTEMS
F
IG. 2.7
F
IG. 2.8
F
IG. 2.9

L = Sum of the total length of exhaust + air intake piping.
11
Exhaust
Type
C12 (xx)
C32 (xx)
C42 (xx)
Restrictor
ø 46 mm
L min = 0.5 m
L max = 1 m
Maximum
Extension
Exhaust/Air
L = 4 m
Risk of Condensation Forming
Coaxial
Systems
ø 60/100
Piping not insulated
ø 46
restrictor NO restrictor
NONE NONE
Piping insulated
ø 46
restrictor NO restrictor
NONE NONE
Exhaust
Type
C12 (xx)
C32 (xx)
C42 (xx)
Restrictor
ø 41 mm
L min = 0.5 m
L max = 1 m
Maximum
Extension
Exhaust/Air
L = 4 m
Risk of Condensation Forming
Coaxial
Systems
ø 60/100
Piping not insulated
ø 41
restrictor NO restrictor
NONE NONE
Piping insulated
ø 41
restrictor NO restrictor
NONE NONE
TABLE 2.1
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
Twin Pipe
Systems
ø 80/80
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
21 RFFI
28 RFFI
Exhaust
Type
C12 (xy)
C32 (xy)
C42 (xy)
C52 (xy)
C82 (xy)
Restrictor
ø 46 mm
L max = 25 m
L max = 22 m
Maximum
Extension
Exhaust/Air
34 m
34 m
34 m
31 m
Risk of Condensation Forming
Twin Pipe
Systems
ø 80/80
Piping not insulated
ø 46
restrictor NO restrictor
3.0 m 4.5 m
3.3 m 4.8 m
Piping insulated
ø 46
restrictor NO restrictor
12.5 m 16.0 m
14.0 m 17.8 m
21 RFFI
28 RFFI
TWIN PIPE
SYSTEMS
FIG. 2.10
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
ø 80 mm.
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 F
LUE PIPE
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).

12
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 ter minal
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.
2.10 ROOM THERMOSTAT
CONNECTION
A

2.11 ELECTRICAL DIAGRAM
13
FIG. 2.12
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

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
B. Inlet Gas
C. Central Heating Return
2.12 G
AS AND W
ATER CIRCUITS
F
IG. 2.14
FIG. 2.13
1
2
3
4
5
6
7
8
9
10
17
16
15
14
13
11
12

15
3. D.H.W. STORAGE
CYLINDER
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 T
ABLE
3.1 for a
selection of ARISTON unvented cylinders).
F
IG. 3.2
3 port valve installation
F
IG. 3.1
2 port valve installation
3.1 2
PORT AND 3 PORT VALVE
INSTALLATIONS
Wiring to 2 port valve installation
using an external 2 channel
programmer
Type Danfoss FP715
Type Honeywell ST6400C
FIG. 3.3