Ariston MicroCombi 23 MFFI User guide

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microCombi 23/27 MFFI

Installation and Servicing Instructions

Type C Boilers

G.C.N: 47-116-16 (23kW) G.C.N: 47-116-24 (27kW)

LEAVE THESE INSTRUCTIONS WITH THE END-USER

Country of destination: GB, IE

TABLE OF CONTENTS

1. GENERAL INFORMATION PAGE.3

1.1 G

1.2 O

ENERAL INSTRUCTIONS PAGE.3 VERALL VIEW PAGE.4

2. INSTALLATION PAGE.4

2.1 R

2.2 SITING THE APPLIANCE PAGE.5

2.3 O

2.4 CLEARANCES PAGE.6

2.5 MOUNTING THE APPLIANCE PAGE.7

2.6 E

2.7 GAS CONNECTION PAGE.8

2.8 WATER CONNECTION PAGE.8

2.9 FLUE CONNECTION PAGE.10

2.10 C 2,11 REMOVING THE FRONT PANEL PAGE.17

2.12 ROOM THERMOSTAT

2.13 ELECTRICAL/SYSTEM DIAGRAMS PAGE.19

2.14 WATER CIRCUIT DIAGRAM PAGE.20

EFERENCE STANDARDS PAGE.4

VERALL DIMENSIONS PAGE.6

LECTRICAL CONNECTION PAGE.7

ONTROL PANEL PAGE.17

CONNECTION PAGE.18

3. COMMISSIONING PAGE.21

3.1 I

3.2 INITIAL STA RT-UP PAGE.22

3.3 OPERATIONAL ADJUSTMENTS PAGE.22

3.4 COMBUSTION ANALYSIS PAGE.23

3.5 P

3.6 BOILER SAFETY SYSTEMS PAGE.23

3.7 D

3.8 COMPLETION PAGE.24

3.9 OPERATIONAL CHECKS PAGE.24

3.10 I

NITIAL PREPARATION PAGE.21

RODUCT OF COMBUSTION

DISCHARGE MONITORING PAGE.23

RAINING THE SYSTEM PAGE.24

NSTRUCTING THE END USER PAGE.25

4. GAS ADJUSTMENTS

4.1 CHANGING THE TYPE OF GAS PAGE.26

4.2 ADJUSTING THE GAS PRESSURES (SIT SIGMA)PAGE.26 ADJUSTING THE GAS PRESSURES (HONEYWELL)PAGE.28

6.3.1 REMOVING THE COMBUSTION CHAMBER PAGE.33

6.3.2 REMOVING THE BURNER

JETS PAGE.33

AND

6.3.3 REMOVING THE ELECTRODES PAGE.33

6.3.4 REMOVING THE MAIN HEAT EXCHANGER PAGE.34

6.3.5 REMOVING THE AIR PRESSURE SWITCH PAGE.35

6.3.6 R

EMOVING THE FAN PAGE.35

6.4 ACCESS TO THE GAS VALVE PAGE.36

6.4.1 REMOVING THE SPARK GENERATOR (SIT SIGMA)PAGE.36

6.4.2 REMOVING THE SPARK GENERATOR (HONEYWELL)PAGE.36

6.4.3 R

EMOVING THE GAS VALVE

(SIT SIGMA)PAGE.37

6.4.4 REMOVING THE GAS VALVE (HONEYWELL)PAGE.37

6.5 A

CCESS TO THE WATER CIRCUIT PAGE.38

6.5.1 REMOVING THE PUMP PRESSURE SWITCH PAGE.38

6.5.2 R

EMOVING THE SAFETY

VALVE PAGE.38

6.5.3 REMOVING THE AUTOMATIC AIR VENT PAGE.38

6.5.4 REMOVING THE PUMP PAGE.39

6.5.5 REMOVING THE PRESSURE GAUGE PAGE.40

6.5.6 R

EMOVING THE EXPANSION

VESSEL PAGE.40

6.5.7 REMOVING THE OVERHEAT THERMOSTAT PAGE.41

6.5.8 REMOVING THE CENTRAL

HEATING TEMPERATURE

SENSOR (N.T.C.) PAGE.41

6.5.9 REMOVING THE D.H.W. TEMPERATURE SENSOR (N.T.C.) PAGE.41

6.5.10 REMOVING THE D.H.W. FLOW SWITCH PAGE.42

6.6 ACCESS TO THE CONTROL SYSTEM PAGE.42

6.6.1 C

HECKING THE FUSES PAGE.42

6.6.2 REMOVING THE TIME CLOCK PAGE.43

6.6.3 REMOVING THE P.C.B. PAGE.43

5. MAINTENANCE PAGE.30

6. SERVICING INSTRUCTIONS PAGE.31

6.1 R

6.2 TO GAIN GENERAL ACCESS PAGE.31

6.2.1 R

6.2.2 REMOVING THE SEALED

6.2.3 REMOVING THE SIDE

6.3 A

EPLACEMENT OF PARTS PAGE.31

EMOVING THE FRONT

PANEL PAGE.31

CHAMBER FRONT PANEL PAGE.32

PANELS PAGE.32

CCESS TO THE COMBUSTION

CHAMBER PAGE.33

7. FAULT FINDING PAGE.44

7.1 F

AULT FINDING GUIDE

(FLOW-CHARTS)PAGE.44

8. SHORT SPARE PARTS LIST PAGE.49

9. TECHNICAL INFORMATION PAGE.52

1. GENERAL 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 Users Manual.

1.1 GENERAL INSTRUCTIONS

Read the instructions and recommendations in these Installation and Servicing 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 Servicing Technicians or your installer may need to consult it in the future.

This is a combined appliance for the production of central heating (C.H.) and domestic hot water (D.H.W.).

This appliance 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.

must be used only for the purpose for which it is designed.

If you smell gas in the room, 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 Agent and request the use of original spare parts. For in-guarantee repairs contact MTS (GB) Limited.

do not turn on or off light switches, use the

1.2 OVERALL VIEW

LEGEND:

1. Flue connector

2. Air intake for twin pipe flue systems

3. Fan

4. Combustion chamber hood

5. “Twin-pass” heat exchanger

6. Domestic hot water temperature probe

7. Combustion chamber

8. Combustion chamber insulation panel

9. Burner

10. Detection electrode

11. Ignition electrodes

12. Gas valve

13. Spark generator

14. Pump pressure switch

15. Safety valve (3 bar)

16. Automatic By-pass

17. D.H.W. Flow switch

18. Domestic hot water inlet filter

19. Circulation pump with automatic air release valve

20. Safety thermostat

21. Main circuit temperature probe

22. Expansion vessel

23. Air pressure switch tube

24. Air pressure switch

25. Combustion analysis points

IN028C

2. INSTALLATION

2.1 REFERENCE STANDARDS

FIG. 1.0

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.

In the United Kingdom the installation and initial start up of 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”, the current Building Regulations, reference should also be made to the current ETCI rules for electrical installation.

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 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 7593:1992 Treatment of water in domestic hot water

central heating systems

BS 5546:1990 Installation of hot water supplies for

domestic purposes BS 5440-1:2000 Flues BS 5440-2:2000 Air supply BS 5449:1990 Forced circulation hot water systems BS 6798:1987 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 7671:2001 IEE wiring regulations BS 4814:1990 Specification for expansion vessels BS 5482:1994 Installation of L.P.G.

2.2 SITING THE APPLIANCE

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

I.S. 813 Domestic Gas Installations

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, and in Scotland, the electrical provisions of the Building Regulations applicable in Scotland, 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 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, specifically in accordance with current IEE Wiring Regulations.

The location must permit adequate space for servicing and air circulation around the appliance as indicated in Section

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, non-combustible, permanent wall to prevent access from the rear.

2.3 OVERALL DIMENSIONS

LEGEND:

A = Central Heating Flow (3/4”) B = Domestic Hot Water Outlet (1/2”) C = Gas Inlet (3/4”) D = Domestic Cold Water Inlet (1/2”) E = Central Heating Return (3/4”)

FIG. 2.1

QT002A

2.4 CLEARANCES

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

2.2

FIG. 2.2

DM001B

2.5 MOUNTING THE APPLIANCE

After removing the boiler from its packaging, remove the template from the separate box containing the connection

OTE: Pay particular attention to any test water that

kit. N may spill from the appliance.

Place the template in the position the appliance is to be mounted and after ensuring it is hanging squarely, use it to drill the holes for the hanging bracket and flue pipe(s) For further information relating to the flue installation please refer to Section 2.9 FLUE CONNECTION. (If the appliance is to be fitted on a wall of combustible material, the wall must be protected by a sheet of fireproof material). If the appliance is to be fitted into a timber framed building, guidance should be sought from the Institute of Gas Engineers document R

EF: IGE/UP/7.

2.5.1. Drill the wall and plug using those supplied with the connections kit, position the bracket and secure with the wall bolts supplied. NOTE: It is highly recommended that a spirit level be used to position the appliance to ensure that it is perfectly level.

NB:

FIG. 2.3

2.5.2. Position the appliance on the hanging bracket and connect the isolating valves supplied in the connection kit as shown on the wall template (see also Sections 2.7 Gas Connections, 2.8 Water Connections & F

IG. 2.3).

2.6 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 10, 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.

IMPORTANT!

In the event that the power supply cord must be changed, replace it with one with the same specifications. Note: The diagrams for the electrical system are indicated in section 2.13.

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 appliance is supplied with a fly-lead already connected, this must be connected to a 240v supply fused

at 3A and 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).

Should external controls be required, the design of the external electrical circuits should be undertaken by a competent person, see section 2.12 for further information.

2.7 GAS CONNECTION

2.8 WATER CONNECTIONS

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.

VIEW OF THE BOILER CONNECTIONS

IG. 2.5

KT007A

FIG. 2.4

LEGEND:

A = Central Heating Flow B = Domestic Hot Water Outlet C = Gas Inlet D = Domestic Cold Water Inlet E = Central Heating Return F = Safety Valve Outlet

SC005A

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.

FIG. 2.6

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 radiators.

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.

SAFETY 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.

AIR 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 litres (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.

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, therefore a temporary method for initially filling the system and replacing lost water during servicing in accordance with current Water Regulations and bylaws must be provided

(FIG. 2.6). NOTE: The installer should ensure that

there are no leaks as frequent filling of the heating system can lead to premature scaling of the main exchanger and failure of hydraulic components.

DOMESTIC WATER:

The domestic water must be in accordance with the relevant recommendation of BS 5546:1990. Copper tubing to BS EN 1057:1996 is recommended for water carrying pipe work and must be used for pipe work carrying drinking water, a scale reducer should also be used to reduce the risk of scale forming in the domestic side of the heat exchanger.

CENTRAL HEATING

Fill01

Detailed recommendations are given in BS 6798:1987 and BS 5449-1:1990, the following notes are given for general guidance.

RESIDUAL HEAD OF THE BOILER

VR003A

2.9 FLUE CONNECTIONS

IMPORTANT! FOR ALL FLUE SYSTEMS, A

RESTRICTOR MAY NEED TO BE INSERTED INTO THE EXHAUST MANIFOLD RESTRICTOR AND DETAILS OF FITTING REQUIREMENTS ARE SHOWN IN

, THE SIZE OF THE

TABLE

2.1 (PAGE 16).

FLUE SYSTEM

The provision for satisfactory flue termination 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 and consideration must be given to adjacent boundaries. 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 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. 2.7.

FIG. 2.7

Ø 60/100 mm

ERMINALPOSITION

A - Directly 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

FU010ARev1

N - Fixed by vertical flue terminal

NOTE:THE FLUE MUST NOT TERMINATE IN A PLACE LIKELY TO CAUSE NUISANCE

FIG. 2.8

FU003A

FU002A/Rev.1

FITTING THE COAXIAL FLUE (HORIZONTAL)

(For Telscopic Instructions see below and for Vertical Flue and Twin Pipe Instructions see page 12)

CONTENTS:

X SILICONE O-RING (60mm)

1 1X ELBOW (90O) 2X WALL SEALS (INTERNAL &EXTERNAL) 1X ALUMINIUM FLUE PIPE INCLUDING TERMINAL (1 METRE - 60/100) 2X FLUE CLAMPS 8X SCREWS 2X SEALS

Once the boiler has been positioned on the wall, insert the elbow into the socket

(FIG

2.8) and rotate to the required position.

NOTE: It is possible to rotate the elbow 360

on its vertical axis.

Using the flue clamps, seals and screws supplied

(FIG 2.8) secure the elbow to the

boiler.

The 1 metre horizontal flue kit (705958) supplied is suitable for an exact

dimension

of 823mm, and the 750mm

horizontal flue kit (705785) is suitable for an exact X dimension of 573mm.

FIG 2.9

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

IG 2.8), add 22 mm to this measurement,

-F

you now have the total length of flue required (including the terminal), this figure must now be subtracted from 860mm, you now have the total amount to be cut from the plain end of the flue.

FIG 2.11

IMPORTANT! FOR ALL FLUE SYSTEMS, A RESTRICTOR MAY

NEED TO BE INSERTED INTO THE EXHAUST MANIFOLD DETAILS OF FITTING REQUIREMENTS ARE SHOWN IN

, THE SIZE OF THE RESTRICTOR AND

TABLE 2.1 (PAGE 16).

FIG 2.10

Cut the flue to the required length ensuring that the distance between the inner and the outer flue is maintained (FIG 2.10).

e.g. X = 508mm + 22mm = 530mm

860 - 530 = 330mm (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 through 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.

FITTING THE TELESCOPIC FLUE KIT (HORIZONTAL)

CONTENTS:

X SILICONE O-RING (60mm)

1 1X ELBOW (90O) 2X WALL SEALS (INTERNAL &EXTERNAL)

1X ALUMINIUM FLUE PIPE INCLUDING TERMINAL (TELESCOPIC 60/100)

X FLUE CLAMPS

2 8X SCREWS 2X SEALS

The telscopic flue is suitable for use with an exact minimum X dimension of 270mm and an exact maximum X dimension 470mm.

IMPORTANT!! Do not extend the telescopic flue to an X dimension of more than 470mm. If longer lengths are required use extension pieces as necessary. Under no circumstances must the flue be cut.

The wall must then be made good around the flue (ensuring a fall of 1ois maintained away from the boiler to the flue terminal).

Once made good, place the inner (white) wall seal over the flue and push up to the wall, secure the flue to the elbow by using the clamp supplied.

For each additional 90

elbow 1 metre must be removed from the total flue length (maximum 4 metres including the 1st elbow). For each additional 45oelbow 0.5 metre must be subtracted from the total flue length (FIG 2.13).

FIG 2.12

FITTING THE COAXIAL FLUE (VERTICAL)

(For Twin Pipe Instructions see page 13)

CONTENTS: 1X SILICONE O-RING (60mm)

X CONICAL ADAPTOR (60/100mm)

1 1X VERTICAL FLUE KIT (80/125mm) 3X SCREWS

The vertical flue kit is supplied with a specially designed weather proof terminal fitted, it can be used either with a flat roof or a pitched roof. (see FIGS 2.12, 2.13).

The Vertical flue kits maximum and minimum useable lengths with both flat and pitched roof flashings are indicated in

(Figs. 2.14 & 2.15).

Before proceeding to fit the flue, ensure that the maximum flue length has not been exceeded and that all elbows and bends have been taken into consideration, the maximum

flue length is 4 metres, for each additional 90

elbow 1

metre must be subtracted from the total flue length, and for

each 45

0.5 metres must be subtracted from the total flue

length (the offset and height of 2 x 45ocan be seen in

Fig. 2.16).

NOTE:MAX LENGTH = a+a+a +

b+b = a+a+a+0.5+0.5

OMBINED LENGTH NOT

TO EXCEED 3m

FIG 2.13

Mark the position of the flue hole in the ceiling and/or roof

(see FIG. 2.14 for distance from wall to the centre of the flue).

Cut a 110mm diameter hole through the ceiling and/or roof and fit the flashing plate to the roof. Should it be necessary to cut the flue

DO NOT cut the

outer white ar inlet tube, cut the aluminium exhaust flue 6mm longer than the outer white air tube when used at minimum length.

DO NOT cut more that 250mm from the

FIG 2.14

inner aluminium exhaust flue.

To connect the vertical flue kit directly to the boiler, place the adaptor

(see FIG 2.12) (supplied with vertical flue kit)

onto the exhaust manifold and secure with the clamp, the vertical flue kit must then be inserted through the roof flashing, this will ensure that the correct clearance above the roof is provided as the terminal is a fixed height.

Should extensions be required, they are available in 1

(Part No. 705786), 500mm (Part No. 705790) and

metre 160mm lengths (Part No. 705812), they must be connected directly to the boiler and secured with the clamp supplied before connecting the adaptor to allow the vertical flue kit to be fitted. In the event that extension pieces need to be shortened, they must only be cut at the male end and it must be ensured that the distance between the inner and outer flue are kept (Fig. 2.10).

When utilising the vertical flue system, action must be taken to ensure that the flue is supported adequately to prevent the weight being transferred to the appliance flue connection.

When the flue passes through a ceiling or wooden floor, there must be an air gap of 25mm between any part of the flue system and any combustible material. The use of a ceiling plate will facilitate this. Also when the flue passes from one room to another a fire stop must be fitted to prevent the passage of smoke or fire, irrespective of the structural material through which the flue passes.

FITTING THE FLUE (TWIN PIPE)

Where it is not possible to terminate the flue within the distance permitted for coaxial flues, the twin flue pipe can be used by fitting a special adaptor to the flue connector and using the aperture for the air intake located on top of the combustion chamber.

FIG 2.15

IMPORTANT! FOR ALL FLUE SYSTEMS, A

RESTRICTOR MAY NEED TO BE INSERTED INTO THE EXHAUST MANIFOLD RESTRICTOR AND DETAILS OF FITTING REQUIREMENTS ARE SHOWN IN TABLE

, THE SIZE OF THE

2.1 (PAGE 16).

Minimum offset distance when using 2x 45obends

Considerations necessary for twin flue installation;

It is most important to avoid any possible condense formation entering the appliance.

According to Table 2.1

(Page 16) decide if condensation

will form within the flue. If yes, there are two options;

1) Where condense will form but can be negated with insulated flue, install insulated the flue with a fall of 5mm in every metre away from the boiler.

2) The exhaust flue will have a fall of 3

back to the boiler and a suitable trap will be fitted on the exhaust as close to the boiler as possible, condense will then be suitably disposed of.

Where the flue runs through cold spots, i.e. loft areas, condense is likely to be formed, therefore a fall back to the boiler and a trap is required. Always ensure that the flue is adequately supported, avoiding low points. (MTS supply suitable clamps as Part No. 705778).

FIG 2.16

To utilise the air intake it is necessary to:

Remove the ‘knockout’ of the air intake by cutting it with a suitable knife

(FIG. 2.16).

Insert the elbow/flue pipe into the air intake until it stops.

The twin flue pipes can be fitted with or without additional elbows and need no clamps, simply ensure that the red oring is inserted in the female end of the flue pipe and push the extension piece fully into the previous section of flue pipe or elbow, check that the o-ring is not dislodged when assembling the flue.

Twin pipe can also be converted back to Coaxial flue to enable vertical termination with a coaxial kit by using the pipe bridge (Twin - Coaxial Adaptor - Part No. 705767). When running the twin flue pipe vertically, a condense trap must always be used on the exhaust pipe.

FIG 2.16

It is not recommended that the pipe bridge for horizontal termination, however in the unlikely event that this proves to be a necessity it is extremely important that the entire flue has a fall of 3

back to the boiler, is suitably trapped and where the 60mm inner flue of the concentric terminal connects to the pipe bridge, this point must be adequately sealed with silicone sealant to avoid condense leakage at this point.

NOTE: Vertical twin flue installations must have a trap on

the exhaust. MTS supply a suitable condense trap Part No. 705774 and recommend that this be used in the event that the flue may not form condense.

When siting the twin flue pipe, the air intake and exhaust terminals must terminate on the same wall, the centres of the terminals

must be a minimum of 280 mm apart and the air intake must not be sited above the exhaust terminal (refer to FIG. 2.20). The air intake pipe can be run horizontally, however, the terminal and the final 1 metre of flue must be installed with a fall away from the boiler to avoid rain ingress.

It is also strongly recommended that the air intake pipe run be constructed of insulated pipe to prevent condense forming on the outside of the tube.

The maximum permissible flue length for twin flue is dependent on the type of run used.

IMPORTANT!!!

HERE CONDENSE WILL FORM WITHIN

THE FLUE SYSTEM FALL BACK TO THE BOILER OF SUITABLE TRAP IS FITTED AS CLOSE TO THE BOILER AS POSSIBLE A SUITABLE COLLECTOR

705798

OR A CONDENSATE DISCHARGE

, ENSURE THERE IS A

AND A

. MTS SUPPLY

PART NO.

T WITH BUILT IN TRAP PART NO.

705774.

For flue runs with the intake and exhaust pipes under the same atmospheric conditions (TYPE 4) the maximum length is 43 metres (23kW) and 28 metres (27kW), for runs with the terminals under different atmospheric conditions (TYPE 5) the exhaust terminal must extend 0.5 metres above the ridge of the roof (this is not obligatory if the exhaust and air intake pipes are located on the sa,e side of the building). For TYPE 5 also, the maximum permissible combined length is 40 metres.

The maximum length is reached by combining the total lengths of both the air intake and exhaust pipes. Therefore a maximum length of 40 metres for example, will allow a flue run of 20 metres for the air intake and 20 metres for the exhaust pipes, also for each 90oelbow 1.3 metres must be subtracted from the total length and for each 45oelbow 1 metre must be subtracted from the total flue length. Some of the acceptable flue configurations are detailed on below (FIG. 2.19).

For further information relating to flue runs not illustrated, please contact the Technical Department on 01494

539579.

FIG 2.17

FIG 2.18

EXHAUST

AIR INTAKE

AIR INTAKE MUST NOT BE

FITTED ABOVE THE EXHAUST

TYPE 1

TYPE 2

TYPE 3

TYPE 4

TYPE 5

NOTE:DRAWINGS ARE INDICATIVE OF FLUEING OPTIONS ONLY.

FIG. 2.19

FIG 2.20

23 MFFI

TABLE 2.1

Coaxial

Systems

ø 60/100

Twin Pipe

Systems

ø 80/80

Exhaust

Type

TYPE 1

YPE 2

TYPE 3

Exhaust

Type

TYPE 4

YPE 5

Use the

ø 43 mm

Restrictor

Between

0.5 m - 2 m

Use the

ø 43 mm

Restrictor

Up to 11.5 m

Up to 11.4 m

Do not use the

Restrictor

Between 2 m - 4 m

Do not use the

Restrictor

Between

11.5 m - 43 m

Between

11.4 m - 40 m

Maximum

Flue

Length

4 m

Maximum

Flue

Length

43 m

40 m

Risk of Condensation Forming

NOT APPLICABLE

Risk of Condensation Forming With:

Standard Twin Pipe

After:

Insulated Twin Pipe

After:

N/A*

4.3 m

with a ø 43 mm restrictor

6.9 m

without a ø 43 mm restrictor

5.7 m*

with a ø 43 mm restrictor

N/A*

21.7 m*

without a

ø 43 mm restrictor

Coaxial

Systems

ø 60/100

Twin Pipe

Systems

ø 80/80

27 MFFI

Exhaust

Type

TYPE 1

TYPE 2

YPE 3

Exhaust

Type

TYPE 4

YPE 5

Use the

ø 45 mm

Restrictor

Between

345 mm - 1 m

Use the

ø 45 mm

Restrictor

Up to 14 m

Up to 21 m

Do not use the

Restrictor

Between 1 m - 4 m

Do not use the

Restrictor

Between

14 m - 28 m

Between

21 m - 51 m

Maximum

Flue

Length

4 m

Maximum

Flue

Length

28 m

51 m

Risk of Condensation Forming

NOT APPLICABLE

Risk of Condensation Forming With:

Standard Twin Pipe

After:

7 m

with a ø 45 mm restrictor

7 m

without a ø 45 mm restrictor

Insulated Twin Pipe

After:

10 m*

with a

ø 45 mm restrictor

24 m*

with a ø 45 mm restrictor

24 m*

without a ø 45 mm restrictor

28 m*

without a

ø 45 mm restrictor

Where there is no risk of condense forming (and, therefore no requirement for a condense collector), ensure a minimum

fall of 5mm per metre away from the appliance.

NOTE:UNDER SOME CIRCUMSTANCES, CONDENSE MAY FORM AT THE EXHAUST TERMINAL, SPECIAL ATTENTION MUST BE PAID WITH

REGARD TO POSSIBLE CONDENSE DRIPPING FROM THE TERMINAL

2.10 CONTROL PANEL

LEGEND:

A - On/Off button B - Central heating temperature adjustment C - Domestic hot water temperature adjustment D - Heating system pressure gauge E - Time clock F - Central heating selector G - Central heating L.E.D. (green) H - Flue sensor L.E.D. (yellow) I - Overheat and/or ignition failure (lockout) L.E.D. (red) J - Ignition failure (lockout) and/or overheat reset

button/Flue Test analysis mode* K- ON/OFF L.E.D. (green)

FR019A

* Warning the flue analysis mode must only be selected by a

qualified service engineer.

FIG. 2.20

2.11 REMOVING THE FRONT PANEL

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 manouvering space, it is possible to raise the control panel and rotate it to a fully horizontal position.

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.

2.12 ROOM THERMOSTAT

CONNECTION

To connect a room thermostat, it is necessary to:

1. - Open the control panel as indicated in

SECTION 2.11.

2.- Remove the link “A” from the terminal block on the reverse of the control panel.

3. - Insert the thermostat cable through the cable grommet and fasten it by means of the cable-clamp provided.

4. - Connect the thermostat wires to the terminal block

(Diagram A).

5.- If a remote time clock is to be fitted, disconnect the integral time clock from the P.C.B.

6. - Using a volt-free switching time clock, connect the switching wires from the time clock following points 1-4 above

(Diagram B).

7. - If using an external time clock and room thermostat, these must be connected in series as points 1-7 above (Diagram C).

Note: Only a low voltage room thermostat capable of volt free switching must

be used. Factory fitted integral wiring must not be disturbed when wiring external controls.

FO016A

FO017A

FIG. 2.21

2.13 ELECTRICAL/SYSTEM DIAGRAMS

CN103

CN104

CN201

CN300

CN204

CN202

CN200

CN102

CN100

CN101

CN103

CN104

CN102

CN100

CN101

FIG. 2.22

A - Jumper:

B - Central Heating Temperature Adjustment C - Connector for Remote Control (Climate Manager) D - Domestic Hot Water Temperature Adjustment E - Soft-light Adjustment F - Maximum Heating Adjustment G - Time Clock Connector H - On/Off Switch I - Fume Sensor L.E.D. J - Central Heating Selector K - Ignition Failure (Lockout) L.E.D. L - On/Off L.E.D. M - Reset Button N - Central Heating L.E.D. O - Transformer P - Spark Generator I.C. Q- Gas Valve Relay R - Circulation Pump Relay S - Fan Relay

1 - Don’t move (jumper is factory set in position B) 2 - Anti-cycling Device Adjustment for Heating

3 - Don’t move (jumper is factory set in position B) 4 - Don’t move (jumper is factory set in position B) 5 - Fan/Pump over-run selector

Position A = 0 mins Position B = 2 mins

Position A = OFF Position B = ON

A01 - Circulation Pump A02 - Fan A03 - Spark Generator/Gas Valve Supply A04 - Detection Electrode A05 - Main Circuit Temperature Probe A06 - Domestic Hot Water Temperature Probe A07 - D.H.W. Flow switch A08 - Pump Pressure Switch A09 - Modulator A10 - Air Pressure Switch A11 - Safety Thermostat A12 - External (Room) Thermostat

COLOURS:

Gr - Grey Bi - White Rs - Red Mr - Brown Bl - Blue Nr - Black Ro - Pink

2.14 WATER CIRCUIT DIAGRAM

FIG. 2.23

SI016C

LEGEND:

1. Fan

2. “Twin-pass” Heat Exchanger

3. Domestic Hot Water Temperature Probe

4. Burner

5. Detection Electrode

6. Ignition Electrodes

7. Gas Valve

8. Pump pressure switch

9. Safety Valve

10. D.H.W. inlet filter

11. D.H.W. Flow Switch

12. Automatic By-pass

13. Pressure Gauge

14. Circulation Pump with Automatic Air Release Valve

15. Overheat Thermostat

16. Main Circuit Temperature Probe

17. Expansion Vessel

18. Air Pressure Switch

A. Central Heating Flow B. Domestic Hot Water Outlet C. Gas Inlet D. Domestic Cold Water Inlet E. Central Heating Return

3. COMMISSIONING

3.1 INITIAL PREPARATION

MTS (GB) Limited support the initiative. Within the information pack you will find a copy of the logbook. 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 logbook with them whenever they contact a service engineer or us.

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:

Lower the control panel and remove the case panels (see SECTION 2.11 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 them only when clear water, free of air, is visible.

Purge the air from the pump by unscrewing the pump plug anticlockwise, 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 soundness and remedy any leaks discovered.

FILLING OF THE D.H.W. SYSTEM:

Close all hot water draw-off taps. Open the cold water inlet cock supplied with the connection kit. Open slowly each draw-off tap and close them only when clear water, free of bubbles, is visible.

GAS SUPPLY:

Inspect the entire installation including the gas meter, test for tightness and purge the supply as described in BS 6891:1988. 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 ( 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 (sludge) damaging the boiler and system.

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

SECTION 3.2) and run it until the

3.2 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

2.16) - the L.E.D. “K” will illuminate. Then push the button “F” in for central heating - the L.E.D. 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;

-Open the taps for a brief period;

-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 main burner. If the burner does not light the first time, wait 1 minute and repeat the procedure.

5. Check the minimum and maximum burner pressure values; adjust if needed using the values indicated in the table in

SECTION 4.

“J” for the lighting system; the spark will light the

“G” will illuminate. This will start the

“A” (see FIG.

3.3 OPERATIONAL ADJUSTMENTS

To access the areas in which adjustments are made, it is necessary to open the control panel, as indicated in SECTION 2.11, then remove the rear inspection cover by unscrewing the two screws. Access is thereby provided to the P.C.B. and to the following components:

1. The power supply cable connector;

2. The fuses;

3. The soft-light potentiometer the setting for which can range from the minimum thermal power to the maximum;

4. The maximum thermal heating power potentiometer adjustable by the minimum to maximum power (already calibrated in the factory to 70% of the maximum thermal power);

5. The jumper for adjusting the ignition delay (anti-cycling) feature, which can be set from 0 to 2 minutes (set in the factory at one minute);

Fan/Pump Over-run (Electrical Diagram). When the jumper is set to position A the Fan and Pump over-run is activated. (The jumper is factory set in position B)

7. The time clock connector.

3.4 COMBUSTION ANALYSIS

3.5 PRODUCT OF COMBUSTION DISCHARGE MONITORING

FU008A

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 O etc. To access these intakes it is necessary to unscrew the front screw and remove the metal plate with sealing gasket. It is possible to activate the flue test mode (maximum output) by pressing and holding the RESET button 10 seconds, the yellow L.E.D. “ return to normal operation after 5 minutes. The boiler can be returned to normal operation sooner by switching the boiler off and on again.

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 (23 Kw) - 0.90 mbar (27Kw) under conditions of maximum thermal power in order for the boiler to function properly and without interruption.

H” will light. The boiler will

and CO2,

“J” for

3.6 BOILER SAFETY SYSTEMS

FU009A

The boiler is fitted with the following devices (see SECTION 2.10 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. “I” will illuminate to signal the shutdown status. The system can be reset by pressing and releasing the button “J” 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 “D” 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 reset 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. “I” 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 “J” button.

4. ANTI-FROST DEVICE: The boiler is fitted with a device which, in the event that the water temperature falls below 3

˚C, the burner ignites at the minimum power

until the boiler reaches a temperature of 33˚C.

This device only operates if the boiler is functioning perfectly and:

- the system pressure is sufficient;

- the boiler is powered electrically;

- the gas is turned on.

6 - EXHAUST DISCHARGE ANOMALY SHUTDOWN:

The boiler is fitted with safety devices, which in the event of defective discharge of exhaust products, automatically interrupts the gas supply, thereby shutting off the boiler. The shutdown of the boiler is temporary and is indicated by the illumination of the yellow L.E.D. “H” for a period of about 15 minutes.

Once this time period has passed and the discharge state of exhaust fumes has returned to normal, the boiler automatically turns back on.

7 - PUMP PROTECTION:

To prevent the pump from seizing the boiler will activate the pump for 20 seconds every 21 hours after it’s last operation.

3.7 DRAINING THE SYSTEM

3.8 COMPLETION

DRAINING THE HEATING SYSTEM

The heating system must be drained as follows:

- Turn off the boiler;

- Attach a hose pipe and open the drain valve;

- Drain 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 pipe work and radiators if the ambient temperature drops below 0°C during the winter. This makes repeated draining of the entire system unnecessary.

DRAINING THE DOMESTIC HOT WATER SYSTEM

Whenever there is the danger of the temperature dropping below the freezing point, the domestic hot water system must be drained as follows:

- Turn off the general water valve for the household plumbing system;

- Turn on all the hot and cold water taps;

- Empty the remaining water from the lowest points in the system (where present).

For the Republic of Ireland 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 edtion of I.S. 813. In addition it is necessary to complete the Log Book.

3.9 OPERATIONAL CHECKS

1. The flue system must be visibly checked for soundness.

2. On Central Heating allow the system to warm up and manipulate the Central Heating temperature control knob, check the burner modulates up and down between the high and low settings.

3. Range rate the thermal power for Central Heating, as detailed in

4. Run the Domestic Hot Water, manipulate the Domestic Hot Water temperature control knob to check the burner modulates up and down between the high and low settings.

5. Balance the Central Heating system until all return temperatures are correct and equal.

6. Turn ON/OFF button OFF, disconnect the pressure Gauge, retighten screw and relight boiler.

7. Re-examine Central Heating, Domestic Hot Water and Cold Water supplies for soundness.

SECTION 4.2

8. Check the appearance of the gas flame to assess the adequacy of the combustion air supply.

9. If external controls have been disconnected, reconnect and test.

10. Refit boiler casing.

3.10 INSTRUCTING THE END USER

1. Hand over the copy of the End User Instructions supplied with the appliance,

together with these instructions, and explain how to use the timeclock and room thermostat if fitted.

2. Show the End User how to switch the appliance off quickly, and indicate the position of the electric supply isolator.

3. Inform the End User of the location of all drains, isolating valves and air vents.

4. Explain how to turn the appliance off for both short and long periods and advise on the precautions necessary to prevent damage in the event that the appliance is inoperative when freezing conditions occur.

5. Finally advise the End User that, for continued safe and efficient operation, the appliance must be serviced by a competent person at least once a year.

4. GAS ADJUSTMENTS

Model CATEGORY II2H3+ Methane Gas

G20

23 MFFI 27 MFFI

23 MFFI Main Burner: n. 12 jets (ø) mm

27 MFFI Main Burner: n. 13 jets (ø) mm

4.1 CHANGING THE

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

Consumption (15°C; 1013mbar) m3/h Consumption (15°C; 1013mbar) Kg/h Gas Burner Pressure max - min mbar

Consumption (15°C; 1013mbar) m Consumption (15°C; 1013mbar) Kg/h Gas Burner Pressure max - min mbar

The boiler can be converted to use either methane (natural) gas (G20)

TYPE OF GAS

or L.P.G. (G30 - G31) by an Authorised Service Centre.

The operations that must be performed are the following:

45.67 20 20

1.30

2.78

----

11.0 - 2.0

1.3

3.10 - 1.16

---

12.2 - 1.7

1. Replace the jets on the main burner (see table in section 4);

2. Adjust the maximum and minimum thermal capacity values for the boiler

(see table in section 4 and 4.2 Adjusting the Gas Pressures);

3. Adjust the maximum thermal power setting;

4. Adjust the soft-light feature

pressure);

5. Adjust the ignition delay feature for the heating system by adjusting the potentiometer as shown in

Liquid Butane Gas

G30

80.58 29 28

0.77

----

2.02

27.7 - 6.0

0.77

---

2.31 - 0.87

27.8 - 5

Liquid Propane Gas

G31

80.58 37 36

0.77

----

2.00

35.5 - 7.3

0.77

---

2.27 - 0.85

35.8 - 5.3

(see table below for recommended

FIG. 4.1 (can be set from 0 to 2 mins.).

CATEGORY

II2H3+

Recommended

Soft-light Pressure

(mbar)

4.2 ADJUSTING THE GAS PRESSURES (SIT SIGMA)

Setting the minimum and the maximum power of the boiler

1. Check that the supply pressure and dynamic pressure to the gas valve is

a minimum of 20 mbar for natural gas.

2. To do this, loosen the screw “A”.

Fit the pipe of the pressure gauge to the inlet pressure connection of the gas valve “B” and check for the correct standing pressure, then operate the appliance and check for the correct working pressure. When you have completed this operation, replace the screw “A” securely into its housing to seal off the gas (check for tightness).

3. To check the pressure supplied by the gas valve to the burner, loosen the screw “C”. Fit the pipe of the pressure gauge to the pressure outlet test

Model

Microcombi

Methane Gas

G20

Liquid

Butane Gas

Propane Gas

G30

23 MFFI 8.0 16.0 16.0

27 MFFI 6.7 12 12

Liquid

G31

4.2 ADJUSTING THE GAS PRESSURES (SIT SIGMA)

point of the gas valve “D”.

Disconnect the compensation pipe “D1” either from the gas valve or from the sealed chamber.

4. Push the On/Off button to “ON” position -green light- and ensure that the hot water temperature control knob is set to maximum.

Turn on the boiler by running a hot water tap. Adjust the 10mm nut “E” on the modureg to set the maximum gas pressure, turn the nut clockwise to increase and anti clockwise to decrease the pressure until the required pressure is achieved (see TABLE

A page 30).

5. To set the minimum power, disconnect a supply terminal “F1” from the

modureg and adjust screw “F” (ensure that the 10mm nut is held in position). Turn the screw clockwise to increase the pressure and anticlockwise to decrease the pressure (displayed on the pressure gauge) corresponding to the minimum power (see TABLE A page

30).

6. When you have completed the above operations, turn off the hot water tap, reconnect the supply terminal to the modureg on the gas valve, reconnect the compensation pipe and replace the cap on the screw of the modureg.

Setting the maximum heating circuit power

7. To set the maximum heating circuit power, push the On/Off button to the

“ON” position -green light- and push the Heating button and set the time clock and any external controls to the “ON” position -green light. Turn the knob of the heating thermostat clockwise to maximum.

8. Remove the inspection panel of the P.C.B. and fit a small cross-head

screwdriver in to the right hand potentiometer (see below). Turn clockwise to increase the pressure or counter-clockwise to reduce the pressure. Adjust the setting to the required heating pressure value (displayed on the pressure gauge), as indicated in the charts shown on pages 30 and 31.

9. Turn off the boiler by placing the main switch to the "OFF" position.

Setting the pressure for soft-light ignition.

Disconnect the detection electrode connection close to the P.C.B. (FIG.

2.13). Start the boiler and during the ignition sequence adjust the left hand potentiometer until the gas pressure reads the required gas pressure (see the table on page 29). Once the gas pressure is set turn off the boiler and re-connect the detection electrode to the P.C.B. NB.: It may be necessary to reset the flame failure reset a number of times during this operation.

10. Remove the pipe from the test point and tighten the screw “C” to the

pressure test point in order to seal off the gas.

11. Carefully check the pressure test points for gas leaks (valve inlet and

outlet).

IMPORTANT!

Whenever you disassemble and reassemble the gas connections, always check for leaks using a leak detection fluid.

Soft-light

Adjustment

Max Heating

Adjustment

4.2 ADJUSTING THE GAS VALVE (HONEYWELL)

Recommended pressure for soft-light ignition

8 mbar

NATURAL GAS (G20) BUTANE GAS (G30) PROPANE GAS (G31)

16 mbar

6.7 mbar 12 mbar

12 mbar

23 Kw

27 Kw

Setting the minimum and the maximum power of the boiler

1. Check that the supply pressure and dynamic pressure to the gas valve is

a minimum of 20 mbar for natural gas.

2. To do this, loosen the screw “A”. Fit the pipe of the pressure gauge to the inlet pressure connection of the gas valve “B” check for the correct standing pressure, then operate the appliance and check for the correct working pressure. When you have completed this operation, replace the screw “A” securely into its housing to seal off the gas (check for tightness).

3. To check the pressure supplied by the gas valve to the burner, loosen the screw “C”. Fit the pipe of the pressure gauge to the pressure outlet test point of the gas valve “D”. Disconnect the compensation pipe “D1” either from the gas valve or from the sealed chamber.

4. Push the On/Off button to “ON” position -green light- and ensure that the hot water temperature control knob is set to maximum.

A page 30)

5. To set the minimum power, disconnect a supply terminal “F1” from the

modureg and adjust screw “F” (ensure the 10mm nut is held in position). Turn the screw clockwise to increase the gas pressure and counterclockwise to decrease the gas pressure (displayed on the pressure gauge) corresponding to the minimum power (see TABLE A page

30).

6. When you have completed the above operations, turn off the hot water tap, re-connect the supply terminal to the modureg on the gas valve and replace the cap on the screw of the modureg.

Setting the maximum heating circuit power

7. To set the maximum heating circuit power, push the On/Off button to the

“ON” position -green light- and push the Heating button and set the time clock and any external controls to the “ON” position -green light. Turn the

knob of the heating thermostat clockwise to maximum.

8. Remove the inspection panel of the P.C.B. and fit a small cross-head

screwdriver in to the right hand potentiometer (see page 28). Turn clockwise to increase the pressure or counter-clockwise to reduce the pressure. Adjust the setting to the required heating pressure value

(displayed on the pressure gauge), as indicated in the charts shown on pages 30 amd 31.

9. Turn off the boiler by placing the main switch to the "OFF" position.

Setting pressure for soft ignition.

Disconnect the detection electrode connection close to the P.C.B. (FIG.

11.14).

Start the boiler and during the ignition sequence adjust the left hand potentiometer until the gas pressure reads the required gas pressure as per the table below. Once the gas pressure is set turn off the boiler and re-connect the

connection to the P.C.B. NB.: It may be necessary to reset the flame failure reset a number of times during this operation.

10. Remove the pipe from the test point and tighten the screw “C” to the

pressure test point in order to seal off the gas.

11. Carefully check the pressure test points for gas leaks (valve inlet and

outlet).

IMPORTANT!

Whenever you disassemble and reassemble the gas connections, always

check for leaks using a leak detection fluid.

NOTE: ALWAYS CHECK THE GAS RATES FOLLOWING ADJUSTMENT.

23 MFFI

2.78

11.0

2.0

1.16

2.02 Kg/h

0.87 Kg/h

27.5 mbar

6.2 mbar

28 mbar

12 x 0.77

2.00 Kg/h

0.85 Kg/h

35.5 mbar

7.3 mbar

37 mbar

12 x 0.77

TABLE A

Regulating the heating power for

natural gas (G20)

Regulating the heating power for

butane gas (G30)

CG010A

CG011A

Regulating the heating power for

propane gas (G31)

5. 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 3.4) and cleaning of the burner if needed.

5 - If necessary, dismantling and cleaning of the combustion

chamber. 6 - If necessary, 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 gas pressure, gas rate and soft-light, 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). 11- Check of the electrical connection (ensure it complies with the

instructions in the manual). 12- Check of Domestic Hot Water production efficiency (flow rate and

temperature) 13- General check of the combustion by-products of the

discharge/ventilation system. 14- Check of the general performance of the unit.

6. SERVICING INSTRUCTIONS

To ensure efficient safe operation, it is recommended that the boiler is serviced annually by a competent person.

Before starting any servicing work, ensure both the gas and electrical supplies to the boiler are isolated and the boiler is cool.

Before and after servicing, a combustion analysis should be made via the flue sampling point (please refer to SECTION 3.4 for further details).

After servicing, preliminary electrical system checks must be carried out to ensure electrical safety (i.e. polarity, earth continuity, resistance to earth and short circuit).

6.1 REPLACEMENT OF PARTS

The life of individual components vary and they will need servicing or replacing as and when faults develop. The fault finding sequence chart in which component is the cause of any malfunction, and instructions for removal, inspection and replacement of the individual parts are given in the following pages.

6.2 TO GAIN GENERAL ACCESS

SECTION 7 will help to locate

2. The control panel moves downward and when pulled forward,

rotates on two lateral hinges; the panel stays in a semihorizontal position, which allows access to the inner parts of the boiler (F

3. In order to increase the manoeuvring space, it is possible to

raise the control panel and rotate it to a fully horizontal position (F

4. Remove the screws “B” from the front panel bottom lip

(FIG. 6.4);

5. Lift the front panel up and forward from the raised screws at the

the top of the casing (F

FIG. 6.4

IG. 6.2);

IG. 6.3);

IG. 6.5).

All testing and maintenance operations on the boiler require the control panel to be lowered. This will also require the removal of the casing.

6.2.1 Removing the front panel

1. Loosen the fastening screws “A” of the control panel located

on the lower part of the panel itself. (F

FIG. 6.1

IG. 6.1);

FIG. 6.2

FIG. 6.5

FIG. 6.3

6.2.2 Removing the sealed chamber front cover

6.2.3 Removing the side panels

1. Remove the screws “C” (FIG. 6.6);

2. Lift the sealed chamber front cover from the locating pins (FIG.

6.7).

1. Remove the four screws “D” for each side panel (FIG.6.8);

2. Pull the panel away from the boiler at the base, then lift the

panel up and remove from the boiler (FIG.6.9).

FIG. 6.8

FIG. 6.6

FIG. 6.9

FIG. 6.7

6.3 ACCESS TO THE COMBUSTION CHAMBER

6.3.1 Removing the combustion cover

Remove the screws “E” (FIG. 6.10);

2. Lift off the combustion cover.

Fig. 6.12

6.3.3 Removing the electrodes

FIG. 6.10

6.3.2 Removing the burner and jets

1. Remove the screws “F” from the burner (FIG. 6.11);

2. Remove the burner (FIG. 6.12);

3. Disconnect the electrodes (see SECTION 6.3.3);

4. Remove the jets using a No. 7 socket spanner;

5. Replace in reverse order.

Before carrying out this procedure, unscrew and slide the burner forward (see previous section).

1. Remove rubber gasket “G” (FIG. 6.13);

2. To remove the detection electrode disconnect the cable

at its connection point close to the P.C.B. (FIG. 6.14);

3. Remove screw “H” (FIG. 6.15);

4. Gently slide the electrode downward (FIG. 6.16).

FIG. 6.13

FIG. 6.11

FIG. 6.14

6.3.4 Removing the main heat exchanger

FIG. 6.15

1. Drain the boiler of water;

2. Remove the overheat thermostat sensor, D.H.W. sensor

and heating sensor “I” (FIG. 6.17);

3. Release the four connection nuts “J” connecting the

exchanger to the flow and return pipes (F

4. Pull it straight out (FIG. 6.19).

IG. 6.18);

Fig. 6.17

FIG. 6.16

To replace, repeat the steps in reverse order, paying particular attention to the following: a -Centre the electrode in the positioning hole carefully,

otherwise the electrode may break;

b -Ensure that the left hand and right hand electrodes are

located the correct way round (facing each other), to give the correct spark gap;

c -Check that the cables have been connected correctly; d -Check that the rubber gasket seals the cable/ electrode

connection point completely.

FIG. 6.18

FIG. 6.19

6.3.5 Removing the air pressure switch

6.3.6 Removing the fan

1. Disconnect the electrical connections “K” and silicone

pipes “L” from their connection points (F

IG. 6.20);

2. Remove screws “M” on the top of the sealed chamber (FIG.

6.21);

3. Lift out the air pressure switch (FIG. 6.22);

4. Unscrew to remove the switch from the plate.

FIG. 6.20

FIG. 6.21

1. Disconnect electrical connections “N” and silicone pipe “O”

IG.6.23);

2. Remove screw “P” and remove the fan collar clamp “Q”

(FIG.6.24);

3. Remove screws “R” (FIG.6.25);

4. Remove fan and mounting plate (FIG.6.26).

FIG. 6.23

FIG. 6.24

FIG. 6.25

FIG. 6.22

FIG. 6.26

6.4 ACCESS TO THE GAS VALVE

6.4.1. Removing the spark generator (SIT SIGMA Gas Valve)

Disconnect ignition leads “S” by pulling upward

(FIG. 6.27A);

2. Remove the screw “T” (FIG. 6.28A);

3. Remove the spark generator by pulling forward from the

gas valve (FIG. 6.29A).

FIG. 6.27A

6.4.2. Removing the spark generator (HONEYWELL Gas Valve)

Disconnect ignition leads “S” by pulling upward

(FIG. 6.27B);

2. Remove the screw “T” (FIG. 6.28B);

3. Remove the spark generator by pulling forward from the

gas valve (FIG. 6.29B).

FIG. 6.27B

FIG. 6.28A

FIG. 6.29A

FIG. 6.28B

FIG. 6.29B

6.4.3 Removing the gas valve (SIT SIGMA)

6.4.4 Removing the gas valve (HONEYWELL)

tant! Before removing the gas valve, ensure the gas

Impor

supply is turned off.

1. Disconnect all the cables from the solenoid and

modureg;

2. Remove the spark generator (see previous section);

3. Release the nuts “U” (FIG. 6.30A);

4. Remove the screws “V” from the bottom of the gas valve

(FIG. 6.31A);

5. Remove the gas valve (FIG. 6.32A).

tant! Before removing the gas valve, ensure the gas

Impor

supply is turned off.

1. Disconnect all the cables from the solenoid and

modureg;

2. Remove the spark generator (see previous section);

3. Release the nuts “U” (FIG. 6.30B);

4. Remove the screws “V” from the bottom of the gas valve

(FIG. 6.31B);

5. Remove the gas valve (FIG. 6.32B).

FIG. 6.30A

FIG. 6.31A

FIG. 6.30B

FIG. 6.31B

FIG. 6.32A

FIG. 6.32B

6.5 ACCESS TO THE WATER CIRCUIT

Important! Before any component is removed, the boiler must be drained of all water.

6.5.1 Removing the pump pressure switch

1.Remove the pump pressure switch electrical connections

“W” (FIG 6.33);

2.Unscrew the pump pressure switch by

the nut;

3.Remove the pump pressure switch.

using

a spanner on

6.5.3 Removing the automatic air vent

Unscrew valve top “Y” (FIG. 6.35);

2. Remove valve complete with float (FIG 6.36).

FIG. 6.35

FIG. 6.33

6.5.2 Removing the safety valve

Disconnect the discharge pipe work from below the

boiler;

2. Unscrew and remove the valve “X” (FIG. 6.34).

FIG. 6.36

FIG. 6.34

6.5.4 Removing the pump

Remove the U-clip “ Z” (FIG. 6.37);

2. Remove the retaining clip “A1” (FIG. 6.38);

3. Release the nut “C1” (FIG. 6.39);

4. Remove the pipe “D1” (FIG. 6.40);

5. Remove the screws “E1” (FIG. 6.41);

6. Remove the pump.

FIG. 6.39

FIG. 6.37

FIG. 6.40

FIG. 6.38

FIG. 6.41

6.5.5 Removing the pressure gauge

6.5.6 Removing the expansion vessel

Remove the U-clip “F1” (FIG. 6.42)

2. Remove the pressure gauge coupling (FIG. 6.42);

3. Push the pressure gauge through the control panel

from the rear (F

IG. 6.43).

FIG. 6.42

Release nuts “G1” and remove the gas pipe (FIG. 6.44);

2. Release nut “H1” (FIG. 6.45);

3. Remove back-nut “I1” (FIG. 6.46);

4. Remove the expansion vessel (FIG. 6.47).

FIG. 6.44

FIG. 6.43

FIG. 6.45

FIG. 6.46

FIG. 6.47

6.5.7 Removing the overheat thermostat

Disconnect the overheat thermostat electrical

connections “J1” (FIG. 6.48);

2. Then remove the thermostat from its mounting by

releasing the securing clip (F

IG. 6.49 /6.50).

FIG. 6.48

6.5.9 Removing the D.H.W. temperature sensor (N.T.C.)

Pull off the electrical connector and unscrew the sensor

probe using a suitable spanner (FIG. 6.52).

FIG. 6.49

FIG. 6.50

6.5.8 Removing the heating temperature sensor (N.T.C.)

Pull off the electrical connector and unscrew the sensor

probe using a suitable spanner (FIG. 6.51).

FIG. 1.52

FIG. 6.51

6.5.10 Removing the D.H.W. flow switch

Unplug the electrical connector “M1” (FIG. 6.53);

2. Release nut “N1” (FIG. 6.53a);

3. Release the nut “O1” (FIG. 6.53b) and remove the

D.H.W. flow switch.

6.6 ACCESS TO THE CONTROL SYSTEM

Important! Isolate the electrical supply to the boiler before accessing the control panel.

6.6.1 Checking the fuses

Remove the inspection cover on the reverse of the

control panel (FIG. 6.54);

2. Remove the fuses (FIG. 6.55).

FIG. 6.53

FIG. 6.54

FIG. 6.55

FIG. 6.53a

FIG. 6.53b

6.6.2 Removing the time clock

6.6.3 Removing the P.C.B.

Disconnect the electrical connections “P1” from the

clock (FIG. 6.56);

2. Remove screws “Q1” (FIG. 6.57);

3. Lift out the time clock from the control panel (FIG. 6.58).

FIG. 6.56

Isolate electricity;

2. Remove the inspection cover from the reverse of the

control panel;

3. Unplug all electrical connections from the P.C.B.

4. Remove the screws “R1” (FIG. 6.59);

5. Separate the facia panel from the rear of the control

panel ;

7. Remove the screws “S1” and remove the P.C.B.

(FIG. 6.60).

FIG. 6.57

FIG. 6.59

FIG. 6.60

FIG. 6.58

7. FAULT FINDING

7.1 FAULT FINDING GUIDE

(FLOW-CHARTS)

These fault finding guides are not exhaustive. However, it is possible to detect and correct many defects by using the standard fault finding diagrams described in this chapter, ensure these guides are carried out in the set order.

To ensure that the external controls do not interfere with the fault finding, disconnect the wires from the terminal block on the rear of the control panel and provide a solid link between the terminals.

4546474849

8. SHORT SPARE

PARTS LIST

microCombi 23/27 MFFI

998616 573521 573528 998447 569390 995903 996047 998836 999091 999599 999724 65100248 999245 998484 571651 995349 999397 998894 998458 998619 996158 995991 996072 998424 574279 999919 65100249 997089 65100244 573520 998433 998517 998623 65100251 998622 65100250 998624 996065 998716 998717

Key

no.

G.C. part

no.

ARISTON

Part No.

Description

6 15 18 19 20 23

25A 25B

40A 40B

50A 50B

66A 66B

69 70

72A 72B

77 78 80

81A 81B 82A 82B

83 86 92

95A 95B 96A 96B

97 99

321 322

E61 468 164 282 164 229

164 261

E61 490

E61 520

E61 547

E61 483

E61 485

164 225

E61 565

E61 567

E61 569 E25 425 E61 665 E61 667

Expansion vessel Gasket 3/8" Gasket 1/2" Safety valve (1/4" 3 bar) Gasket 1/4" Pump pressure switch Return group Pump Pump Time clock P.C.B. (T2 MFFI) P.C.B. (27 MFFI) Pressure gauge Air pressure switch Air pressure switch Gasket (Fan) Fan (23 kW) Fan (27 kW) Temperature probe Exchanger Burner 12 ramp (natural gas) Burner 13 ramp (natural gas) D.H.W. Flow Switch O-ring Gasket Spark Generator Spark Generator Gas valve (SIT 845 SIGMA) Gas valve (HONEYWELL) Gasket 3/4" Burner jet (natural gas 1.30) Gasket Electrode (ignition R.H.) Electrode (ignition R.H.) Electrode (ignition L.H.) Electrode (ignition L.H.) Detection electrode Thermostat (overheat) Burner jet 1.30 full kit (natural gas) Burner jet 0.77 full kit (LPG)

1 1 1 1

1 1 1 1 1 1 1 1 1 1 1 1 1

1 1

1 1 1 1

1 1 1 1 1 1 1 1 1 1 1 1

NOTES

9. 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 % Max Discharge of Products of Combustion (G20) Kg/h Residual Discharge Head mbar Consumption at Nominal Capacity(G20) m Gas Consumption after 10 Minutes* m

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

Content %

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 Domestic Hot Water Temperature (approx) max/min °C D.H.W. Flow Rate ∆T=35°C l/min D.H.W. Minimum Flow Rate l/min Pressure of Domestic Hot Water max/min bar 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/Hz Power Consumption W Protection Grade of Electrical System IP Internal Fuse Rating Weight Kg

23 MFFI

63AU4547

25.6/11.0

23.7/9.6

92.5

90.5

1.0

6.5

0.4

0.96

2.72

0.32

2.02/2.00 126

7.0

8.0 38 +5

200

0.25 82/42 54/36

9.7

2.5

6/0.2

6 1

130

30-37

230 / 50

135

X4D

FAST 2 AT

27 MFFI

0694BM3512

29.3/11.0 27/9.3

88.8

1.3

6.7

0.4

57.7

1.41

3.10

0.36

2.31/2.27

148.5

7.1

8.0 53

200

0.25 82/42 56/36

11.0

2.5

6/0.2

6 1

130

28-37

230/50

155

X4D

FAST 2 AT

G.C. Number 47-116-16 47-116-24

*Calculated at 70% maximum output

Manufacturer: Merloni TermoSanitari SpA - Italy

Commercial subsidiary: MTS (GB) LIMITED

MTS Building Hughenden Avenue High Wycombe Bucks HP13 5FT

Telephone: (01494) 755600 Fax: (01494) 459775 Internet: http://www.ariston.co.uk E-mail: info@uk.mtsgroup.com

Technical Service Hot Line: (01494) 539579

0 99 84 1589 311 Edition 1 Revision 1 - 10/07/03

End User Manual

microCombi 23 MFFI microCombi 27 MFFI

Leave These Instructions With the End User

Country of destination: GB / IE

Dear Customer,

Thank you for choosing an ARISTON boiler. We guarantee that your boiler is a reliable and technically sound product. This manual provides detailed instructions and recommendations for proper installation, use and maintenance. Remember to keep this manual in a safe place for future reference i.e. by the gas meter. Your local MTS Servicing Centre is at your complete disposal for all requirements.

The guarantee on this appliance is valid for 12 months from the first day of installation.

Repairs to the electric, hydraulic or gas circuits may be carried out only by your local

authorised MTS Servicing Centre.

Every attempt has been made to avoid errors of any kind

in this manual, the Management invites customers to inform

of any inaccuracies which they may find.

This will help to improve our service

TABLE OF CONTENTS

1. GENERAL INFORMATION page 3

Technical Information page 3 Control Panel page 4

2. OPERATING INSTRUCTIONS page 4

3. USEFUL INFORMATION AND TROUBLESHOOTING page 6

4. MAINTENANCE page 7

5. CHANGE OF GAS TYPE page 7

6. TIME CLOCK page 7

IMPORTANT!

Please read this manual carefully. For additional information, please consult the “Installation and Servicing Instructions.” Make sure to keep the manuals provided with the appliance so that they can be used by the end-user, installer or local service agent.

1. GENERAL INFORMATION

MTS (GB) Limited support the initiative. Your installer will give you, and show you how to use, a Log Book which will give you important information about your boiler, and heating system. Please have this Log Book to hand whenever you contact a service engineer or us.

All CORGI Registered Installers carry a CORGI ID card, and have a registration number. Both should be recorded in your boiler Logbook. You can check your installer is CORGI registered by calling CORGI direct on :- (01256) 372300.

This is a combined appliance for the production of Central Heating (C.H.) and Domestic Hot Water (D.H.W.). This appliance designed. The manufacturer declines all liability for damage caused by improper or negligent use. Do not allow children or inexperienced persons to use the appliance without supervision. If you smell gas in the room, do not turn light switches on or off, 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 (on 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. Consult the Installation and Servicing manual when turning off the boiler for long periods of time.

Before any intervention within the boiler it is first necessary to isolate the electrical supply by turning the external switch to “OFF”.

TECHNICAL INFORMATION

must be used only for the purpose for which it is

GENERAL DATA

Heating input max-min Heating output max-min Efficiency at Maximum Thermal Capacity (see installation instructions)

CENTRAL HEATING

Operating Temperature max-min Maximum-Minimum Heating Pressure Built-in expansion vessel - Total capacity

DOMESTIC HOT WATER

Temperature of Water for Domestic Use (max-min) Working pressure max-min Flow rate ∆T 35°C Minimum flow rate

ELECTRICAL DATA

Electrical Supply/ Frequency Power Consumption Protection of Electrical System

Ariston MicroCombi 23 MFFI User guide

Specifications and Main Features

Frequently Asked Questions

User Manual