MCZ VEGA Guide

Pellet stoves
Installation and use
manual

Contents
2.1 Working environment
2.2 Preparation
2.3 Installation and fitting
2.4 Connection to the external air intake
2.5 Connection to the flue
2.6 Connection to an external fluepipe in insulated or double-walled pipe
2.7 Connection to a chimney or flue duct
2.8 Operating problems caused by draught defects in the flue
2.9 Fitting the ceramic cladding
Chapter 3 Use of the stove
Preface
Symbols used
1.1 Guarantee conditions
1.2 Safety instructions
1.3 Operating instructions
1.4 Safety devices
1.5 Operating principle
1.6 The pellets
1.7 Models of stove VEGA-ASTRA-AURORA-ANTARES
1.8 Technical characteristics
3.1 Checks to make before lighting the stove
3.2 Loading the pellets
3.3 Instructions and advice on first lighting
3.4 Control panel
3.5 Managing the stove with the LCD remote control
3.6 Settings to carry out before first lighting
3.7 Setting the current time
3.8 Selecting the display language
3.9 Selecting the recipe according to the type of pellet used
3.10 How to display and program the selected recipe
3.11 Manual operation: lighting the stove using the control panel or the remote
3.12 Automatic operation with the digital room thermostat
3.13 Passing from manual operation to automatic
3.14 Passing from automatic operation to manual
3.15 Automatic operation with the timer-thermostat
3.16 Programming the timer-thermostat
3.17 Operation of the stove using the external thermostat
3.18 Connecting the external thermostat
3.19 Watching the flame
3.20 Alarm signals
3.21 Other messages
3.22 Lockout of the stove
3.23 Shutting the stove down
3.24 Locking the keyboard on the control panel and the LCD remote
Chapter 2 Installation
Chapter 1 Information
Introduction
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Chapter 4 Maintenance
4.1 Periodical cleaning and checks
4.2 Cleaning the glass
4.3 Monthly check
4.4 Check to be carried out every 2 or 3 months
4.5 Non-scheduled maintenance
4.6 Shutting the stove down (end of season)
4.7 Replacing the batteries in the remote control
4.8 Replacing the fuse in the main switch
4.9 Checking the internal components
4.10 Maintenance summary
Chapter 5 Electrical system
5.1 Electrical system 45
5.2 Maintenance and/or replacement of the electronic boards 46
Chapter 6 Useful tips in case of problems during operation 47
Chapter 7 Accessories for pellet stoves 50
Chapter 8 Spare parts for pellet stoves 51
Chapter 9 Memo for the installer 56
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Chapter 10 Summary of main instructions 58

3
Preface
Dear Customer,
We would like to thank you for the preference which you have decided to bestow on MCZ
products, and particularly for choosing one of the MCZ Pellet range. We are convinced that as
you use it, you will appreciate the quality of the product, which is the fruit of careful planning and
meticulous testing. Our object is to combine technological complexity with simplicity of use, and,
above all, with safety.
In order to get the best performance from your stove and to enjoy to the full the warmth
and the sense of well-being which the flame will diffuse through the home, we recommend
that you read this booklet carefully before lighting the stove for the first time.
Once you have learnt the basics, you will be able manage to best advantage the various levels of
power and the potential for presetting, and you will also pick up a few little hints about cleaning
and setting.
While thanking you again, may we remind you that the stove MUST NOT be used by children, and
that they must always be kept at a safe distance from it!
Introduction
Information
Symbols used
Warning and safety notice
This warning sign, used at various points in this booklet, indicates that the message to
which it refers should be carefully read and understood, because failure to comply with
what these notices say can cause serious damage to the stove and put the user's safety
at risk.
Information
This symbol is intended to highlight information important for the proper functioning of the
stove. Failure to comply with what these notices say will compromise the use of the stove
and is likely ro result in unsatisfactory operation.

MCZ guarantees the stove, excluding the components listed below which are subject to normal
wear and tear, for a period of two years from the date of purchase, as proved by a supporting
document which gives the name of the vendor and the date on which the sale took place. The
guarantee is conditional on the guarantee certificate being filled in and returned within 8 days, and
requires that the product be installed and tested by a specialised installer, according to the
detailed instructions given in the instruction booklet supplied with the product.
The term 'guarantee' is to be understood to denote the free-of-charge replacement or repair of
parts recognised to have been defective at the start by reason of manufacturing defects.
Limitations
The above guarantee does not cover components relating to electrical and electronic parts, or
fans, on which the guarantee periood is 1 year from the purchase of the product, documented as
specified above. The guarantee also does not cover parts subject to normal wear and tear:
gaskets, glass, and all the removable parts of the firebox.
The replacement parts will be guaranteed for the remainder of the guarantee period starting from
the date of purchase of the product.
Exclusions
Variations in colour in the painted or ceramic parts, and crackling of the glaze on the ceramics, do
not constitute grounds for a claim under the guarantee, as they are natural characteristics of the
material and of the use of the product.
The guarantee does not cover any parts which may be found to be faulty as a result of negligence
or carelessness in use, or of incorrect maintenance, or of installation not complying with MCZ's
specification (see the relevant chapters in this user manual).
MCZ refuses to accept any responsibility for any damage which may be caused, directly or
indirectly, by persons, animals or things in consequence of the failure to observe all the
prescriptions laid down in the instruction booklet, especially those concerning warnings on the
subject of installation, use and maintenance of the appliance.
In the event of failure of the product, the staff of the technical assistance department will arrange
for its repair in the shortest time possible from the request, always provided that no claim shall
arise from the period in which th product cannot be used.
Damage caused by transport and/or handling is excluded from the guarantee.
For installation and use of the product, reference must be made exclusively to the booklet
supplied.
The guarantee will be invalidated in the event of damage caused by tampering with the appliance,
atmospheric agents, natural disasters, electrical discharges, fire, defects in the electrical system,
and lack of, or incorrect, maintenancein terms of the manufacturer's instructions.
CLAIMS UNDER THE GUARANTEE:
the request for action under the guarantee must be addressed to the retailer, who will for-
ward the claim to MCZ's technical assistance service.
MCZ refuses to accept any responsibility in the event that the stove or any other accessory
have been improperly used or modified without authorisation.
For all replacement of parts, only original MCZ spare parts must be used.
MCZ DECLARES THAT THE STOVE WHICH YOU HAVE
PURCHASED COMPLIES WITH EEC DIRECTIVE 89/336
and 72/23 and SUCCESSIVE AMENDMENTS
1.1 Guarantee conditions
Information 4

Installation of the stove, making the electrical connections, checking its operation, and
maintenance are all tasks which should be carried out by qualified and authorised
personnel.
Install the stove in accordance with the regulations in force in your local area, region and
country.
For the correct use of the stove and of the electronic apparatus connected to it, and to prevent
accidents, the instructions given in this booklet must always be followed.
In addition, adjustment and regulation must be carried out by adults. Errors or incorrect settings
can give rise to hazardous conditions and/or bad running.
Before beginning any operation, the user, or whoever is preparing to operate on the stove, must
have read and understood the entire contents of this instruction booklet.
The stove must be used only for the purpose for which it is intended. Any other use must be
considered improper and therefore dangerous.
Do not use the stove for standing on or as any kind of support.
Do not put washing to dry on the stove. Any clotheshorses and suchlike must be kept a suitable
distance from the stove. – Danger of fire.
All responsibilty for improper use is taken entirely by the user and such use relieves MCZ of any
civil or criminal responsibility.
Any kind of tampering or unauthorised substitution of non-original spare parts can be hazardous
for the safety of the operator and relieves MCZ of any civil or criminal responsibility.
Most of the surfaces of the stove are extremely hot (the door, the handle, the glass, smoke
discharge pipes etc.). Avoid coming into contact with these parts, therefore, without adequate
protective clothing or suitable implements, such as gloves with thermal protection or implements
which leave the hands cool.
Carefully explain this hazard to elderly people, disabled people and particularly to all children,
keeping them away from the stove while it is running.
On no account should the stove be run with the door open or the glass broken.
Do not touch the stove with wet hands, in view of the fact that it is an electrical appliance. Always
disconnect the supply cable before doing anything to the unit.
Before carrying out any cleaning or maintenance operation, make sure in advance that the the
stove is disconnected from the mains electricity supply, by turning off the main switch located on
the back of the stove, or by unplugging the supply cable.
The stove must be connected to an electrical system which is equipped with an earth conductor,
as laid down in diectives 73/23 EEC and 93/98 EEC.
The system must be of adequate rated capacity for the stated electrical power of the stove.
Incorrect installation or faulty maintenance (not conforming to the requirements set out in this
booklet) can cause harm to people, animals or property. In such cases MCZ is absolved from any
civil or criminal responsibility.
1.2 Safety instructions
Information
5

Information
1.3 Operating instructions
In case of any problems, get in touch with your dealer, or a qualified engineer authorised by
MCZ, and if a repair is necessary, insist on the use of original spare parts.
Shut the stove down in the event of a breakdown or bad running.
Use only the fuel specified by MCZ (6 mm diameter pellets. The fuel must be supplied to the stove
only by the automatic feed system.
Pellets must not be fed manually into the burner.
Periodically check and clean the smoke outlet ducts (connection to the flue pipe).
The accumulation of unburnt pellets in the burner after repeated "ignition failures" must be re-
moved before lighting.
Do not wash the inside of the stove with water.
Do not use water for washing the stove. The water could get inside the unit and damage the
electrical insulation and cause electric shocks.
The pellet stove is not a cooking appliance.
Do not expose your own body to hot air for extended periods. Do not overheat the room which
you are occupying, where the stove is installed. This could cause physical damage and also give
rise to health problems.
Do not expose plants or animals directly to a current of hot air. Both plants and animals could be
harmed by it.
Do not put anything in the hopper other than wood pellets.
Always keep the the cover of the fuel hopper closed.
Keep this instruction manual carefully because it must stay with the stove throughout its working
life. If the stove is sold or transferred to another user, always make sure that the booklet goes with
the product.
If it gets lost, ask MCZ or your authorised dealer for another copy.
Instal the stove in a location which is suitable for firefighting, and equipped with all services such
as air and electricity supply and provision for discharging combustion gases.
If the stove and the ceramic cladding are in storage, it should be in a place that is free of damp,
and they should not be exposed to extremes of temperature.
It is inadvisable to base the stove directly on the floor, and if the floor is made of flammable
material, it must be suitably insulated.
Do not light the stove with flammable materials if the ignition system breaks down.
6

1.4 Safety devices
Information
The stove is fitted with the following safety devices:
PRESSURE SWITCH
Monitors pressure in the smoke duct. It is designed to shut down the pellet feed screw in the
event of an obstructed flue or significant back-pressure (from the wind).
SMOKE TEMPERATURE SENSOR
Monitors the temperature of the smoke, and gives permission for startup or shuts the stove down
when the smoke temperature falls below the preset value.
FUEL HOPPER TEMPERATURE SENSOR.
If the temperature exceeds the preset safety level, it immediately shuts down the running of the
stove, and has to be reset manually before the stove will restart. Take care when carrying out the
operation of resetting it, because if the stove locks out a second time, it will be necessary to call
the technical assistance centre.
ELECTRICAL SAFETY
The stove is protected against violent surges of current by the main fuse, which is located on the
control panel at the rear of the stove. Other fuses to protect the electronic boards (main board and
heat-exchanger board) are to be found on the boards themselves.
FAILURE OF THE SMOKE EXTRACTION FAN
If the fan stops, the electronic board shuts off the supply of pellets in good time, and an alarm
message is displayed.
BREAKDOWN OF THE REDUCTION MOTOR
If the reduction motor stops, the stove continues to function until it has cooled down to the
minimum level.
TEMPORARY POWER OUTAGE
After a brief interruption of the electrical power, the stove relights automatically.
FAILURE TO LIGHT
If during the lighting stagea flame does not start, the stove automatically makes a further attempt
to light.
TAMPERING WITH THE SAFETY DEVICES IS PROHIBITED
It is only after eliminating the cause which gave rise to the intervention of the safety system,
that it is possible to relight the stove and thus reset the automatic operation of the sensor.
Attention !
If the stove is not used as described in this instruction booklet, the manufacturer refuses to
accept any responsibility for damage to persons and property that may arise. The manufacturer
furthermore refuses to accept responsibility for damage to persons and property arising from
the failure to observe all the rules contained in the manual and in particular:
• Failure when carrying out works of maintenance, cleaning and repair to adopt all
necessary measures and precautions.
• Tampering with the safety devices.
• Removing the safety devices.
• Failure to connect the stove to an efficient system for the discharge of smoke.
• Failure to check in advance that the room where the stove is to be installed is
adequately ventilated.
7

1.5 Operating principle
The pellets are picked up from the hopper on board the stove and transported by a feed screw.
They are then introduced into the combustion chamber and fall directly into the stainless steel
grate.
The quantity of pellets introduced into the grate and the corresponding air of combustion are
predetermined, programmed and controlled by an electronic board.
In the lighting phase, the electronic board activates the smoke extraction fan and the ceramic
sparkplug, which heats up and causes the fuel to ignite at a temperature of about 200°C. After
about 20 minutes, the lighting phase is complete, and the control unit puts the stove into operating
mode.
In this phase, on the basis of the instructions which we provide via the infrared remote (5 power
levels), the electronic board regulates the exact relationship between quantity of fuel, combustion
air and convection air, and provides continuous monitoring of all the components connected to it,
indicating if necessary the presence of any operating problems and stopping the process.
Information
Cross-section of
Antares stove
8
1 Door for loading pellets
2 Pellet compartment sensor
3 Outlet for convection warm air
4 Outlet for forced warm air
5 Deflector grille
6 Air for cleaning glass
7 Combustion chamber in Alutec
8 Door with glass (750° C)
9 Grate in stainless steel
10 Secondary combustion air
11 Primary combustion air
12 Central ash drawer
13 Side ash drawer
14 Smoke extractor
15 Door opening handle
16 Ceramic cladding
17 Control panel
18 Rear closing panel
19 Pellet hopper
20 Heat exchange chamber
21 Pellet feeder
22 Pellet feed Archimedes screw
23 Pellet conduit
24 Electronic control board
25 Combustion air intake Ø 50
26 Smoke sensor
27 Smoke outlet Ø 80
28 Warm air fan

Information
Wood pellets are manufactured by hot-extruding compressed
sawdust which is produced during the working of natural dried
wood. The compactness of the material comes from the lignin
which is contained in the wood itself, and allows the production
of pellets without the use of glues or binders.
The market offers different types of pellet with characteristics
which vary depending on what mixture of woods is used. The
diameter varies between 6 mm and 8 mm, with a standard length
in the range 5 mm to 30 mm. Good quality pellets have a density
which varies between 550 kg/m3and 700 kg/m3, with a moisture
content which varies from 5% tp 8% by weight.
With the aim of guaranteeing the stated rate of fuel consumption per hour and ensuring
optimum combustion, MCZ has devised a patented method which allows the identification
and cataloguing of any type of pellet with a 6 mm diameter, in terms of its specific gravity
and particle size.
By using the special measuring container and following the procedure
set out in the paragraph on lighting the stove, the user can determine
the correct settings for configuring the stove.
Besides being an ecological fuel (exploiting timber residues to the
maximum and achieving cleaner combustion than is possible with
fossil fuels), pellets also have technical advantages. While good-
quality timber has a calorific power of 4.4 kW/kg (with 15% moisture,
therefore after about 18 months' seasoning), the equivalent figure for
pellets is 5.3 kW/kg.
To ensure good combustion, the pellets must be stored in an area that
is free of damp, and protected from dirt. Pellets are supplied in 15 kg
bags, so they are very convenient to store.
Good quality pellets ensure good combustion, thus lowering the
emission of harmful agents into the atmosphere.
The poorer the quality of the fuel, the more frequently will
intervention be necessary for cleaning the internal parts, such as
the grate and the combustion chamber.
The pellets must be produced from pure wood which has not been
treated chemically.
The standards DIN 51731 and ONORM M 7135 certify a high-quality
pellet with the following characteristics:
Calorific power: 5.3 kW/kg
Density: 700 kg/m3
Moisture content: 8% max by weight
Ash percentage: 1% max by weight
Diameter: 6-6.5 mm
Length: 30 mm max
Content: 100% untreated wood, with no added bonding substances (bark percentage 5% max)
Packaging: in bags made from ecologically compatible or biodegradable material
MCZ emphatically recommends using certified fuel in its stoves.
The use of fuel of inferior quality or not conforming to the specification given above
compromises the running of your stove and can therefore lead to the termination of the
guarantee and of the manufacturer's responsibility for the product.
Vega, Astra,Aurora and Antares stoves run exclusively on pellets with a diameter of 6 mm
and a length rage from 5 mm to a maximum 30 mm.
1.6 The pellets
Pellet measuring
container
15 kg bags of pellets
9

Technical characteristics
1.7 Vega
d.50 d.80
154 154
162
325
172
1000
530
470
Astra
d.50 d.80
325
154
162
172
1010
570
520
154
10

Aurora
d.50 d.80
154 154
162
325
172
1010570
520
Technical characteristics
Antares
540
570
1160
d.50 d.80
366
214
162
204 204
11

Technical characteristics
Technical characteristics Vega - Astra - Aurora Antares
Overall thermal power
ITALY 8.5 KW / 7310 kcal 9.9KW / 8500 kcal
Overall thermal power
DIN 2,5 KW / 2150 kcal 2.9 KW / 2500 kcal
Efficiency 78 / 81 %
Smoke temperature 120 / 215 °C
Minimum draught
Hopper capacity 23 litres 43 litres
Fuel pellet type Pellet diameter 6 mm. Length range 5-30 mm
Pellet consumption per hour Min 0.6 KG/h Max. 2 KG/h Min 0.7 KG/h Max. 2.2 KG/h
Runtime between feeds Min 27 h Max. 8 h Min 48 h Max. 16 h
Combustion air inlet External diameter 50 mm.
Smoke outlet External diameter 80 mm.
Nett weight 100 Kg. 145 Kg.
Weight with packaging 120 Kg. 170 Kg.
Installed electric power 130 W run. 380 W startup.
Supply voltage 230 V 50 Hz.
0.1 mbar—10 Pa
1.8 Technical characteristics
12

Installation
2.1 Working environment
For proper functioning and a good temperature distribution, the stove should be positioned in a location where
it is able to take in the air necessary for combustion of the pellets (about 40 m3/h must be available) ,as laid
down in the standard governing the installation (UNI - CIG 7129, 7131 and subsequent updates).
The volume of the room must not be less than 30 m3.
The air must come in through permanent openings made in walls (in proximity to the stove) which give onto
the outside, with a minimum cross-section area of 100 cm2.
These openings must be made in such a way that it is not possible for them to be obstructed in any way.
Alternatively, the air may be drawn from rooms next door to the room which needs ventilation, provided that
these rooms have an air intake from outdoors and are not used as bedrooms or bathrooms and provided
there is no fire risk such as there is for example in garages, woodsheds, and storerooms. The provisions of
standards UNI 7129 and 7131 and subsequent amendments absolutely must be respected.
It is not permissible to install the stove in bedrooms, bathrooms or showers, or in
a room where another heating appliance is installed (fireplace, stove etc.) which
does not have its own independent air intake.
Locating the stove in a room with an explosive atmosphere is prohibited.
The floor of the room where the stove is to be installed must be strong enough to take its
weight.
If the walls are not flammable, position the stove with a clearance to the rear of at least 10 cm.
In the case of walls made of flammable material, maintain a minimum clearance to the rear of 20
cm, a clearance to the sides of 50 cm, and a clearance to the front of 150 cm. If the room
contains objects which are believed to be particularly delicate, such as hangings, sofas and other
furniture, their distance from the stove should be considerably increased.
If the floor is made of wood, fit the floor protection plate.
150 cm 20 cm
50 cm
20 cm
Floor protection plate
Min.100 cm²
Clearance distances between the stove and
flammable walls (all measurements to be taken
from the outside surface of the appliance).
13

Installation
2.2 Preparation
The Vega stove is delivered in a single package.
Astra, Aurora, and Antares stoves are delivered in two
packages:
The first contains the stove unit Fig.1
The second contains the ceramic cladding.Fig.2
Open the packaging, take off the bands, remove the
stove unit from the pallet and position it in the chosen
location, taking care that its position complies with the
above instructions.
The main stove unit must always be moved in an
upright position and a trolley must always be used.
Take particular care to see that the door and its glass
are protected from mechanical impact which could
damage them.
Moving the product must always be done with care.
If possible, unpack the stove in the area where it is
going to be installed.
The materials which make up the packaging are not
toxic or harmful, so no special procedures for disposal
by required.
Their storage, disposal or possible recycling are
therefore the responsibility of the final user, in
compliance with current legislation on the subject.
Do not store the stove unit or its cladding without their
packaging.
14
Fig.1
Fig.2

Installation
2.3 Installation and fitting
Installation and assembly of the stove must be carried out by a qualified engineer.
The stove must be installed in a suitable position to allow the normal operations of opening and
ordinary maintenance.
The site must be:
• capable of providing the environmental conditions for operation
• provided with a suitable electricity supply: 230-240 V 50 Hz (EN73-23)
• capable of taking an adequate system for smoke discharge
• provided with external ventilation
• provided with an earth connection complying with CEI 64-8
The stove must be connected to a flue pipe or an internal or external vertical conduit
conforming to the standards UNI 7129 - 7131 – 9615.
The stove must be positioned in such a way that the electrical plug is accessible.
IMPORTANT !
The stove must be connected to a flue pipe or a vertical conduit which can
discharge the fumes at the highest point of the building.
The fumes are however derived from the combustion of wood products, and if
they come into contact with or close to walls, they can make dirty marks.
Also take care because the fumes are very hot but almost invisible, and can cause burns
on contact.
The holes for the passage of the smoke pipe and for the intake of air from outside should
be made before positioning the stove unit.
2.4 Connection to the external air intake
It is essential that at least as much air must be able to flow into the room where the stove is
installed as is required for proper combustion in the appliance and for the ventilation of the room.
This can be effected by means of permanent openings in the walls of the room to be ventilated,
which give onto the outside, or by single or collective ventilation conduits.
For this purpose, make a hole right through an external wall in proximity to the stove, with a
minimum free section of 100 cm² (equivalent to a round hole of 12 cm diameter or a square hole
10x10 cm), protected by a grille on the inside and the outside.
The air intake must:
• communicate directly with the room where the stove is installed
• be protected by a grille, metal mesh or suitable guard, as long as this does not reduce the
area below the minimum.
• be positioned in such a way as to be impossible to
obstruct
It is not compulsory to connect the air intake directly with the
stove (so that it draws air directly from outside), but it is essential
at all events to ensure an airflow of 50 cubic metres per hour by
the use of a hole of the dimensions given.
See standard UNI 10683 REV. Grille for external air intake
15

Installation
When making the hole for the passage of
the smoke discharge pipe, it is necessary
to take into account the possible
presence of flammable materials. If the
hole will be going through a wall made of
wood or any other material which is
sensitive to heat, the INSTALLER MUST
first of all use the special wall union
(diam.13cm minimum) and properly
insulate the pipe of the stove that passes
through it, using adequate insulation
materials (thickness1.3—5cm with
minimum thermal conductivity of 0.07 W/
m°K).
The same is true if the stove pipe must
run through vertical or horizontal
stretches passing in proximity (min.20cm)
to the heat-sensitive wall
As an alternative we recommend the use
of insulated pipe, which can also be used
on the outside to avoid condensation.
Combustion air
intake ø 50
Smoke
outlet ø 80
Pipes and unions with suitable gaskets
must always be used, to guarantee a
hermetic seal.
All sections of the smoke duct must be
inspectable and removable to enable
periodic internal cleaning. Tee connectors
with inspection caps should be used.
Position the stove bearing in mind all the
instructions and considerations above.
Important
All 90 degree changes of direction in
the flue pipe must be fitted with
suitable tee connectors to allow the
possibility of inspection (see the pellet
stove accessory list).
It is absolutely unacceptable to fit a
grille on the end of the discharge pipe,
because it could lead to poor running
of the stove.
Inspection
cover
Inspection cover
Inspection
cover
Minimum1.5-2metres
Maximum2-3metres
Height greater than 4 metres
Gradient3-5%
Smoke duct
16

Installation
Lining up the
smoke outlet and
the connecting
pipe
If the stove needs to be connected to a discharge pipe which goes through the rear wall (to
connect up with the flue), take the greatest care to make sure that the joint is not stressed. Use
the four adjustable feet (Fig. 3) to get the stove correctly levelled so that the smoke outlet is lined
up with the connecting pipe. If the smoke outlet of the stove is forced or used improperly to
lift it or position it, the operation of the stove can be damaged irreparably. (Fig. 4)
Some typical examples of correct installation are illustrated below.
2.5 Connection to the flue
The flue of must have internal dimensions not
larger than 20x20 cm or diameter 20 cm. In the
case of a flue with larger dimensions or in poor
condition (e.g. cracks, poor insulation etc.), it is
advisable to line the flue with a stainless steel
pipe of suitable diameter for its entire length,
right up to the top (Fig 5).
Check with suitable instruments that there is a
minimum draught of 12 Pa.
At the bottom of the flue pipe, provide an
inspection cap to allow periodic checking and
cleaning, which must be done annually.
Make a gas-tight connection to the flue pipe,
using pipes and connectors as recommended
by us.
It is imperative that a windproof cowl should be
fitted which complies with the standards in
force (UNI 7129 - 7130 - 9615).
This type of connection ensures the
evacuation of the fumes even in the
event of a temporary power cut.
Windproof
cowl
50 cm
Flue
Inspection
cover
17
Fig.3 Fig.4
Fig.5

Installation
2.6 Connection to an
external fluepipe in insulated
or double-walled pipe
The external fluepipe must have internal dimensions
of minimum 10x10 cm or 10 cm diameter, and
maximum 20x20 cm or 20 cm diameter.
Check with suitable instruments that there is a
minimum draught of 12 Pa. (Fig. 6)
The only type of pipe which is permissible is
insulated (double-walled) stainless steel, smooth on
the inside, fixed to the wall. Flexible stainless steel
pipe must not be used.
At the bottom of the flue pipe, provide an inspection
cap to allow periodic checking and cleaning, which
must be done annually.
Make a gas-tight connection to the flue pipe, using
pipes and connectors as recommended by us.
It is imperative that a windproof cowl should be fitted
which complies with the standards in force (UNI
7129 - 7130 - 9615).
This type of connection ensures the
evacuation of the fumes even in the
event of a temporary power cut.
2.7 Connection to a
chimney or flue duct
For proper functioning, the connecting pipe between
the stove and the chimney or flue duct must have a
slope of not less than 3%. The length of the
horizontal stretch must not exceed 2/3 metres, and
the vertical distance between one tee connector
and another (change of direction) must not be less
than 1.5m.
Check with suitable instruments that there is a
minimum draught of 12 Pa. (Fig. 7)
At the bottom of the flue pipe, provide an inspection
cap to allow periodic checking and cleaning,
which must be done annually.
Make a gas-tight connection to the flue pipe, using
pipes and connectors as recommended by us.
It is imperative that a windproof cowl should be fitted
which complies with the standards in force (UNI
7129 - 7130 - 9615).
This type of connection ensures the
evacuation of the fumes even in the
event of a temporary power cut.
18
50 cm
Insulated
external
pipe
Inspection
cover
Fig.6
50 cm
Flue pipe
Inspection
cover
Max 2-3 metres
Gradient
3-5%
Min 1.5-2 metres
Fig.7

Installation
2.8 Operating problems caused by draught defects in the
flue
Example 1: 8 m/sec wind blowing
downwards at 45°
Example 2: 8 m/sec wind
blowing horizontally
Depression of 30Pa
Wind
High-pressure zone Low-pressure zone
Least favourable points Most favourable position
Descending wind
Wind 1
2 3
4
Among all the meteorogical and geographical factors
which influence the operation of a flue (rain, fog, snow,
altitude above sea level, amount of sunlight, exposure to
different compass directions), the wind is certainly the one
which has most effect. Besides the thermal depression
brought about by the difference in temperature between
the inside and outside of the flue, there exists another kind
of depression (and overpressure): the dynamic pressure
induced by the wind. A rising wind always has the effect of
increasing the depression and therefore the draught. A
horizontal wind increases the depression if the cowl is
correctly installed. A descending wind always has the
effect of reducing the depression and sometimes of
reversing it.
Besides the direction and force of the wind, the position of the flue and the cowl with respect to
the roof of the building and the surrounding landscape is important. The wind also influences the
operation of the chimney indirectly by creating high-pressure and low-pressure zones, not only
outside the building but inside as well. In rooms directly exposed to the wind (2), an indoor high-
pressure area can be created which can augment the draught in stoves and fireplaces, but it can
be counteracted by the external high pressure if the cowl is situated on the side exposed to the
wind (1). On the other hand, in the rooms on the opposite side from the direction of the wind (3), a
dynamic depression can be created which competes with the natural thermal depression
developed by the chimney, but this can be compensated for (sometimes) by locating the flue on
the opposite side from the direction of the wind (4)
1-2 High-pressure zones
3-4 Low-pressure zones
The operation of the pellet stove is noticeably
sensitive to the conformation and position of
the flue which is adopted.
Hazardous conditions can only be overcome
by suitable setting-up of the stove carried out
by qualified MCZ personnel.
Trees/hills/other buildings
19