SOLZAIMA SZM W Plus 25kW User manual

Wood Fired Boiler
Instruction Manual
English
Model
Wood Fired Boiler SZM
W Plus 25kW, 30kW,
35kW and 40 kW
Read these instructions carefully before installing, using and servicing the unit. The
instruction manual is an integral part of the product.
Mod. 67-E

Thank you for purchasing a SOLZAIMA appliance.
Please read this manual carefully and keep it for future reference.
* All our products fulfil the requirements of the Construction Products Directive
(Directive 8 /106/EEC) and have been approved with the CE conformity mark;
* The Pellet Burning Free Standing Fires are designed according to EN 14785:2008
Standards;
* SOLZAIMA disclaims any responsibility for damages to the unit if installed by non-
qualified personnel;
* SOLZAIMA is not responsible for any damage to units not installed and used in
compliance to the instructions included in this manual;
* All local regulations, including but not limited to national and European standards,
must be observed when installing, operating and servicing the unit;
* Whenever you need assistance, you should contact the supplier or installer of your
equipment. You should provide the serial number of your stove that is located on the
nameplate on the back of the equipment and on the sticker, s glued to the plastic
cover of this manual.
*The technical service must be performed by the unit Installer or Supplier, except on
situations where the assessment performed by the installer or service engineer
determines that SOLZAIMA should be contacted, if required.
Contacts for technical support:
www.solzaima.pt
apoio.clien[email protected]
Address: Rua dos Outarelos; nº 111;
3750-362 Belazaima do Chão
Águeda – Portugal

Contents
1. Package content ......................................................................................... 2
1.1. Unpacking the boiler ............................................................................ 2
2. Safety Precautions .............................................................................. 2
2.1. For your safety, please remember ......................................................... 3
3. Technical Specifications ............................................................................... 3
4. Wood Boiler Installation .............................................................................. 8
5. Installing the Ventilation Kit (optional) ..........................................................
6. Installation Requirements .......................................................................... 13
7. Installing pipes and fume exhaust systems .................................................. 15
8. Hydraulic Installation ................................................................................ 16
8.1 Calculation for the minimum volume of the buffer tank ........................... 17
8.2 Method of calculating the volume expansion vessel................................. 17
. Fuel ........................................................................................................ 1
10. First Use................................................................................................ 21
11. Lighting ................................................................................................. 22
12. Maintenance and Cleaning ................................................................. 22
13. Installation Diagrams .............................................................................. 24
14. Life cycle of the wood fired boiler ............................................................. 27
15. Sustainability ......................................................................................... 27
16. Glossary ................................................................................................ 28
17. Warranty ............................................................................................... 30
17.1. Model specific conditions .............................................................. 30
17.2. Warranty General Conditions ........................................................ 30
18. Statement of Performance ....................................................................... 3

1
Sol aima
Solzaima's vision has always been to provide the cleanest, renewable and more cost-
effective energy possible. This is why for more than 40 years we've been dedicated
to manufacturing biomass heating units and solutions.
As a result of the persistence and unconditional support from a network of partners,
Solzaima is currently the leader in biomass heating units manufacturing, supported
by its range of central heating units with back boilers, pellet boilers and free-standing
fires.
We deliver biomass heating units to approximately 20.000 homes every year. This
effectively demonstrates consumers' interest in more ecological and economic
solutions.
Solzaima has been awarded Quality certification under ISO 001:2015 and
Environmental certification under ISO14001:2015.

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1. Package content
The packaging of the equipment has the following contents:
- Wood Fired Boiler SZM W Plus;
- Packaging with the covers and insulation;
- Manual Instruction Brochure;
- Installer's brochure;
- Characteristics label;
- Energy efficiency label;
- Poker.
1.1. Unpacking the boiler
To unpack the equipment, you should remove the retractable bag that surrounds the
boiler.
2. Safety Precautions
Solzaima shall not liable for any damages to the unit caused by failure to comply with
the specified precautions, warnings and operating procedures.
The units manufactured by Solzaima are easy to operate, special attention was given
to their components to prevent accidental damages to users and installers.
The units must only be installed by an authorised engineer, who should supply the
client with a relevant statement of conformity and who shall be liable for the final
installation and consequent product good operating conditions.
This unit must be used according to its intended use as specified by the manufacturer.
The manufacturer excludes all contractual or non-contractual obligations regarding
damages to people, animals or property arising from the unit’s misuse, faulty
installation or servicing procedure.
After removing the packaging, verify the contents to check their integrity and
completeness. If the contents of the package do not correspond to the items listed
under 1, contact the sales representative from whom you purchased the unit.
The complete set of parts provided with the unit guarantees its operation and energy
efficiency; these parts should only be replaced with original parts provided by an
authorised technical assistance centre.
The unit must be subject to maintenance at least once a year by the installation
engineer.

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This manual is provided with the product. Please keep it close to the unit.
2.1. For your safety, please remember
 The wood fired boiler is a biomass heating unit. Be sure to carefully read and
understand the information contained in this book, before handling or operating the
unit;
 Make sure the hydraulic circuit is correctly assembled and connected to the water
supply system before turning on the wood fired boiler;
 The boiler is not intended for use by children or persons with a physical, sensory
or mental handicap, unexperienced or unaware of its proper use, unsupervised or not
instructed concerning the use of the unit;
 Do not touch the boiler when barefoot or any part of your body is wet or humid;
 Do not tamper with any safety or adjustment features of the unit without the
manufacturer's authorisation;
 Do not cover or reduce the size of the aeration vents existing near the installation
area;
 The wood fired boiler needs air circulation for proper combustion, so possible air
tightness of the location or any existing air extraction sources in the room may
prevent the unit’s proper operation;
 Aeration openings are indispensable for proper combustion. This device must be
installed in a place where the outside air can enter freely. Any air intake grilles must
be placed in a non-blocking location so that sufficient air is available at the installation
site, avoiding poor draught;
 Do not leave the packing materials near children;
 During the unit's normal operation do not attempt to open the boiler's door;
 Avoid direct contact with parts of the unit that overheat during operation;
 Check the fume duct for blockages before turning on the unit after a long period
of inactivity;
 This pellet boiler is intended for residential use in a protected environment.
3. Technical Specifications
The Wood Fired Boiler SMZ W PLUS is intended for heating water for domestic use
and to provide central heating. This requires the pre-installation of a central heating
system and a hot water tank equipped with a heat exchanger (if you wish to use the
appliance to supply domestic hot water).
The Wood Fired Boiler SZM W PLUS is equipped with a large wood capacity

4
combustion chamber (Figure 1), sturdy and user-friendly. This is an atmospheric
(natural draught) boiler.
The boiler is equipped with two doors:
- Lower door: provides access to the area where the ashes fall through the grids, for
cleaning purposes. It is equipped with a lid for the connection of the combustion
auto-regulator. This regulator controls de water temperature inside the appliance,
preventing it to become too hot when the removed heating power is lower than the
produced heating power.
- Upper door: provides access to the wood supply channel and it is where the
combustion occurs.
Figure 1 - Section views of the combustion chamber of the wood fired boiler
Specifications Boiler
W Plus 25 kW
Boiler
W Plus 30 kW
Boiler
W Plus 35 kW
Boiler
W Plus 40 kW
Units
Weight 281 2 5 305 320 kg
Height 1260 1260 1260 1260 mm
Width 530 5 0 620 670 mm
Smoke passages
Upper door
Lower Door

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Depth 1100 1100 1100 1100 mm
Diameter of the fume
discharge pipe 160 180 180 180 mm
Maximum heating
capacity 568 682 7 5 0 m³
Wood log maximum
length 500 500 500 500 mm
Maximum thermal
power (water) 25 30 35 40 kW
Fuel consumption 4, 5 5, 6, 7, kg/h
* Thermal yield at
reduced thermal
power
8 ,8 0,2 0,6 0,7 %
** Thermal yield at
rated thermal power 80 80 80 80 %
CO Emissions with
10% O2 0,044 0,045 0,045 0,046 %
Max. gas temperature 1 3 1 1,5 1 0 1 5,7 °C
Max operating
pressure 3 3 3 3 bar
Draught in the
chimney 18 1 20 21 Pa
Water volume 75 0 105 120 L
Table 1 - Technical specifications
* Tests performed using fuel with a calorific value of 5,08 kWh/kg and a humidity
level of less than 6%.
**Tests performed using fuel with a calorific value of 4,2 kWh/kg and a humidity level
of 16% to 20%.
The above data were obtained in the product type approval tests at independent and
accredited laboratories to test biomass combustion equipment.

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Front Back Side
Figure 2 - Hydraulic connections
a)
Opening of the
output regulator ¾”
Safety
Thermostat
Thermal safety
valve probe inlet
Temperature
probe
Safety valve Hot water
outlet Thermal
safety valve
Primary air
intake
Filling and
draining
old water inlet
Opening of
the output
regulator

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b)
c)
Placing the
probe
1/2"
Hot water
outlet 1.1/4”
Thermal safety valve
probe inlet 3/4"
Drainage outlet
3/4”
Thermal safety
valve probe 1/2”

8
d)
Figure 3 - Hydraulic connections
4. Wood Boiler Installation
Before starting the installation, perform the following actions:
 Check immediately after receipt if the delivered product is complete and in good
condition. Any defects should be noted before installing the appliance.
 Remove the user manual and hand it to the customer.
 Connecting conduit 140 mm in diameter between the flue gas outlet port and a
flue gas exhaust duct to the outside of the building (ex. chimney).
 Do the hydraulic installation (see section 13).
Cold water inlet
1.1/4”
Filling and
draining 1/2"

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5. Installing the Ventilation Kit (optional)
Before installing the ventilation kit, you should immediately check that the kit is
complete and in perfect condition (Figure 4), any damage or lack of elements should
be reported and marked before proceeding with its installation. This chapter will
demonstrate how the optional ventilation kit should be installed.
a) b)
Figure 4 – Ventilation Kit Optional
1 – Remove the nuts and the air intake cover as shown in Figure 5.
a) b) c)
Figure 5 – Remove the cap
2 – Place the two flanges on the fan bracket (Figure 6-a), first point the two nuts as
shown in Figure 6-b. Place the fan on the bracket (Figure 6-c), finally point the last
two nuts and tighten everything to the end as exemplified in Figure 6-d.

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a) b)
c) d)
Figure 6 – Placing the fan
3 – Place the controller on top of the boiler so that it is able to connect the fan cable
and is aligned with the side enclosure, as exemplified in Figure 7-a and Figure 7-b,
fix the controller with the 3 self-piercing screws as exemplified in Figure 7-c.
a) b) c)
Figure 7 – Placement of the fan controller
4 – Place the temperature probe of the controller on top of the boiler as shown in
Figure 8-a, 8-b and 8-c, and fit the enclosure back correctly.

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a) b) c)
Figure 8 – Placement of the temperature probe
5 – The controller has two connections, one to the circulator and one to the fan
(Figure -a), connect the fan cable to the controller on the corresponding plug (Figure
-b), connect the power cable (Figure -c), and connect to the circulator of the Figure
-d installation.
a) b)
c) d)
Figure 9 – Placing the wiring
6 – To start the fan just press the "ON/OFF" button (P4), the controller will order the
fan (VALM M) to start and it will work until the "PUMP" Set Point temperature is
reached (note: Fan Set Point (VALV M) must be the same as Pump Set Point, e.g.
60°C), at that moment the pump led lights up and the pump starts to work, when
the firewood load is finished and the temperature of the pump Set Point drops, the

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fan starts again for a period of 15 min after that time, if the temperature does not
reach the Set Point value of "VALV M" the fan switches off. To start the fan again, it
will be necessary to give the order manually.
Figure 10 – Display
7 – To change the Pump Set Point on the controller, press the "MENU (P1)" button
once, the Set Point value of the pump appears (the controller has a serial Set Point
of 60°C), press the "+ (P2)" or "- (P3)" button to increase or decrease the Set Point
temperature (it is recommended to set the Set Point value greater than or equal to
60°C), to return to the initial menu simply press the "MENU (P1)" button 3 times.
8 – To change the fan Set Point (VALV M) on the controller, press the "MENU (P1)"
button three times, the set point value of "VALV M" appears (the controller has a
serial set point of 60°C), press the "+ (P2)" or "- (P3)" button to increase or decrease
the set point temperature (it is recommended to set the set point value greater than
or equal to 60°C), to return to the initial menu simply press the "MENU (P1)" button
once.
To turn the controller off, press the "ON/OFF (P4)" button until the OFF led is turned
on, to turn the controller back on, press the "ON/OFF (P4)" button again until the
boiler temperature appears.
Button
MENU Button
ON/OFF
Led
VENTILATOR
Led PUMP
Led “OFF”

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6. Installation Requirements
The minimum distances from the wood boiler to flammable surfaces are shown in
Figure 11.
At the top of wood boiler, it is necessary to maintain a minimum distance of 100 cm
from the ceiling of the room especially if they contain flammable material in their
composition.
The base on which the boiler is supported must not be of combustible material, so
adequate protection must always be provided.
a) b)
Figure 11 – Minimum distances to all surfaces: a) top view of the installation of equipment; b) side view of
the installation device
In Figure 12 and Figure 13, the basic requirements for the installation of the boiler
flue are shown. Provide a T for the periodic inspections and the annual maintenance,
as exemplified in the figures. Double-walled insulated stainless-steel pipes should be
used properly to avoid condensation.

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Figure 12 – Side view of the installation, with the inspection point
Figure 13 – Example of typical installation
NOTICE!
Keep combustible and flammable materials at a safe distance.

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7. Installing pipes and fume exhaust systems
 The construction of the gas exhaust pipe must be suitable for the purpose in
accordance with local requirements and respecting the regulations.
 Important! An inspection T must be inserted at the outlet of the exhaust
pipe of the wood-fired boiler with an airtight cover to permit regular inspection or
discharge of heavy dust and condensate.
 The exhaust duct must be mounted in such a way that cleaning and maintenance
is ensured by insertion of the inspection points.
 Under normal operating conditions, the drawdown of the combustion gases must
lead to a depression depending on the of 18 to 21 Pa, measured 1,5 m above the
boiler outlet.
 The wood boiler cannot share the chimney with other equipment.
 The chimneys installed outside the house must be double-walled in stainless steel.
 The exhaust pipe can generate condensation, in this case it is advisable
to establish suitable condensate collection systems.
Failure to meet these requirements undermine the proper functioning of the
boiler. Comply with the instructions given in the diagrams.
The boilers work with the combustion chamber in depression, so it is absolutely
necessary to have a flue pipe that extracts the flue gases properly.
Fume duct material: The pipes to be installed must be rigid, of stainless steel and
have a minimum thickness of 0,5 mm, with joints for the union between the different
sections and accessories.
Isolation: Smoke ducts must be double wall insulated to ensure that the fumes do
not cool during the course to the exterior, which would lead to improper drainage and
condensation that could damage the appliance.
“T” output: Always use an inspection "T" on the boiler outlet.
Chimney crown: you should always install a chimney crown to prevent the return
of fumes.
Depression in chimney: Any other type of installation must ensure a depression of
18 to 21 Pa (depending on the boiler model) measured at hot and at maximum power.

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8. Hydraulic Installation
* You can find in chapter 13 (installation diagrams) possible connection schemes in
the context of a central heating installation, with or without domestic water heating;
* The minimum connection temperature of the circulation pump should be 60°C. It
is advisable to install an anti-condensation valve to avoid condensation phenomena
inside the boiler;
* The pump must be applied in the return circuit, where the temperature is lower;
* The thermostat should be diving, and just like the combustion regulator, it should
be applied to the hot water outlet pipe;
* Solzaima advises an open pot installation, and the pipe connecting it to the boiler
return should not have a diameter of less than 20 mm. No vents should be installed;
* If the installation option is for closed expansion vessel, it should not be sized
according to the installation and the safety valves should be 3 bar (suitable for use
up to 0°C). An additional pressure and temperature safety valve (3bar / 0°C) is
recommended.
* For the purpose of emptying the appliance, a tap shall be placed at one of the exits
provided for that purpose in the lower area of the appliance;
* The heat transport fluid must be water with the addition of an anti-corrosion, non-
toxic product and in the quantity recommended by the product manufacturer;
* The automatic combustion regulator prevents the water temperature inside the
appliance from rising too high if the thermal power removed is lower than that
produced. It does this by reducing the primary air intake and therefore decreasing
the combustion speed. This is an important protection and safety mechanism,
preventing water from boiling and/or the pressure from increasing too much, by
making emergency safety devices work. The regulator must be placed on the thread
indicated in the diagram and must be adjusted to close the primary air inlet door at
80°C - in order to achieve proper operation of any of the equipment referred
to in this manual, the automatic combustion regulator must always be
installed.
* If there is a risk of freezing in the space in which the recovered is located or in the
fluid lines, the installer shall add antifreeze to the circulating fluid in the proportion
recommended by its manufacturer to avoid freezing at the minimum absolute
temperature expected.
* Never connect the stove without the hydraulic circuit being filled with fluid and in
full operation.

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* It is essential to be able to access the various components of your hydraulic
installation during the useful life of your equipment in order to be able to carry out
regular maintenance and intervene or replace components that are necessary over
time.
8.1 Calculation for the minimum volume of the buffer tank
Calculation for the minimum volume of the buffer tank according to the European
standard EN 303-5: 2012 apply the following formula,
VSP = 15 x TB x QN x (1-0,3 x QH/Q
min
)
Where:
VSP = minimum volume buffer tank (l)
TB = combustion time (h)
QN = rated power (kW)
QH = needed for installation (kW)
Q
min
= minimum boiler output (kW)
Example of calculation of the buffer tank:
Combustion Duration: 2 hours (the time required for combustion of the fuel charge)
Nominal boiler power: 32 kW
Minimum boiler power: 32 kW
Thermal load of the building: 25 kW
Minimum volume required = 15 x 2 x 32 x (1-0,3 x 25/32) ≈ 735 l
8.2 Method of calculating the volume expansion vessel
The volume of an enclosed membrane expansion vessel (diaphragm) for a heating
installation is calculated using the following formula,
Where:
V = volume of the vessel (l);
e = coefficient of expansion of the water. Calculated based on the difference between
the maximum temperature of the water in the installation and the maximum cold