COSMOGAS MYDENS 60 Service manual

62403579 - R02 01-06-2019_UK
INSTALLATION, USE
AND MAINTENANCE
MANUAL
MYDENS 60
GAS WALL-MOUNTED
CONDENSING BOILER

2
MYDENS 60 COSMOGAS
CONTENTS
1 - GENERAL SAFETY WARNINGS....................................................................................................................5
1.1 - National installation laws and regulations ................................................................................................................ 5
2 - GENERAL INFORMATION .............................................................................................................................6
2.1 - Presentation ............................................................................................................................................................. 6
2.2 - Overview of models.................................................................................................................................................. 6
2.3 - Accessories included................................................................................................................................................ 6
2.4 - Manufacturer ............................................................................................................................................................ 7
2.5 - Meaning of symbols used ........................................................................................................................................ 7
2.6 - Maintenance............................................................................................................................................................. 7
2.7 - Disposal ................................................................................................................................................................... 7
3 - MAIN COMPONENTS.....................................................................................................................................8
4 - OPERATION .................................................................................................................................................10
4.1 - Operation and intended use of the appliance .........................................................................................................11
4.1.1 - Modulating pump .......................................................................................................................................11
4.1.2 - Hydraulic separator....................................................................................................................................11
4.1.3 - Production of domestic hot water...............................................................................................................11
4.1.4 - Types of system .........................................................................................................................................11
4.2 - Precautions for installation ......................................................................................................................................11
4.3 - Characteristic residual head curves at the central heating system ........................................................................ 12
4.4 - Characteristic curve of head losses ....................................................................................................................... 13
5 - INSTALLATION .............................................................................................................................................16
5.1 - Opening the package ............................................................................................................................................. 16
5.2 - Dimensions and minimum distances to be observed............................................................................................. 16
5.3 - Choosing where to install the appliance................................................................................................................. 16
5.4 - Unit assembly......................................................................................................................................................... 17
5.5 - Delivery and return................................................................................................................................................. 17
5.6 - Water supply .......................................................................................................................................................... 18
5.6.1 - Recommendations on characteristics of water in the system ................................................................... 18
5.6.2 - For correct operation of the system make sure that: ............................................................................... 18
5.6.3 - Water treatment in domestic heating systems .......................................................................................... 19
5.7 - Heat circuit outlet ................................................................................................................................................... 19
5.8 - Expansion tank....................................................................................................................................................... 19
5.9 - Low-temperature systems (or underoor heating) ................................................................................................. 19
5.10 - Gas....................................................................................................................................................................... 19
5.11 - Condensate outlet ................................................................................................................................................ 20
5.12 - Safety valve.......................................................................................................................................................... 20
5.13 - Plumbing and gas connections ............................................................................................................................ 20
5.14 - Electrical connections: details .............................................................................................................................. 21
5.14.1 - Connecting the power supply cable ........................................................................................................ 22
5.14.2 – Choosing the room thermostat/programmable thermostat..................................................................... 22
5.14.3 - Connecting the room thermostat/programmable thermostat .................................................................. 23
5.14.4 - CR04 remote time control (on request)................................................................................................... 23
5.14.5 - Installing the external temperature sensor.............................................................................................. 24
5.14.6 - 0-10 VDC type dialogue ...........................................................................................................24
5.14.7 - Alarm contact .......................................................................................................................................... 24
5.15 - Connecting appliances in a cascade.................................................................................................................... 25
5.16 - Connecting the boiler to storage tank with coil..................................................................................................... 26
5.16.1 - Anti-legionella.......................................................................................................................................... 26
5.17 - Exhaust gases outlet and combustion agent air intake pipe ................................................................................ 27
5.17.1 - Type of intake/outlet B23 and B23P........................................................................................................ 28
5.17.2 - “Split 80/80PP” system (polypropylene) (type C43; C53; C83; C93) ...................................................... 29
5.17.3 - “Split 80/80PP” system (Type C43; C53; C83; C93): accessories available........................................... 30
5.17.4 - “Split 80/80PP” system (type C43; C53; C83; C93): installation examples ............................................ 31
5.17.5 - “80/125PP vertical coaxial” system (polypropylene) (Type C13; C33).................................................... 32
5.17.6 - “80/125PP coaxial” system: accessories available ................................................................................. 33
5.17.7 - “80/125PP coaxial” system: installation examples.................................................................................. 34
5.18 - Installing and uninstalling the MYDENS 60 external cover kit (on request) ......................................................... 35
6 - START-UP.....................................................................................................................................................38
6.1 - Start-up .................................................................................................................................................................. 38
6.1.1 - Instructions to the user.............................................................................................................................. 38
6.1.2 - Filling the condensate drain siphon .......................................................................................................... 38
6.1.3 - Filling the central heating system.............................................................................................................. 38

3MYDENS 60
COSMOGAS
CONTENTS
6.2 - General recommendations regarding the gas supply ............................................................................................ 39
6.3 - Type of gas for which the appliance is set. ............................................................................................................ 39
6.4 - Conversion of the appliance from one type of gas to another................................................................................ 40
6.5 - Ignition.................................................................................................................................................................... 42
6.6 - Controlling the supply gas pressure and any adjustments..................................................................................... 43
6.7 - Controlling the level of CO2 and any adjustments ................................................................................................. 44
6.8 - Adjusting the power in central heating line (Range Rated) .................................................................................... 45
7 - USE...............................................................................................................................................................46
7.1 - Checking the cock opening .................................................................................................................................... 46
7.2 - Checking the central heating system pressure ...................................................................................................... 46
7.3 - General information................................................................................................................................................ 47
7.4 - Ignition procedure .................................................................................................................................................. 47
7.5 - Summer operating mode........................................................................................................................................ 47
7.6 - Winter operating mode........................................................................................................................................... 47
7.7 - Adjusting the domestic hot water (if there is a storage tank).................................................................................. 48
7.8 - Central heating....................................................................................................................................................... 48
7.9 - Thermostatic control............................................................................................................................................... 49
7.10 - Climate control ..................................................................................................................................................... 49
7.10.1 - Climate control: which systems?............................................................................................................. 49
7.10.2 - Climate control: precautions during adjustment...................................................................................... 50
7.10.3 - Climate control: setting the parameters .................................................................................................. 50
7.10.4 - Climate control: adaptation to different climate areas............................................................................. 50
7.10.5 - Climate control: switching the central heating service on and off ........................................................... 50
7.10.6 - Climate control with room compensation ................................................................................................ 50
7.11 - Timers for the various functions ........................................................................................................................... 52
7.12 - Pump anti-blocking............................................................................................................................................... 52
7.13 - Anti-freeze protection ........................................................................................................................................... 52
7.14 - “User prole” ........................................................................................................................................................ 53
7.15 - “Installer prole” ................................................................................................................................................... 55
7.15.1 - Parameters for cascade systems............................................................................................................ 59
7.16 - Diagnostics........................................................................................................................................................... 60
7.16.1 - Diagnostics: lockouts “Loc” ..................................................................................................................... 60
7.16.2 - Diagnostics: errors “Err”.......................................................................................................................... 63
7.16.3 - Diagnostics: alarms “AttE” ...................................................................................................................... 66
8 - MAINTENANCE ............................................................................................................................................67
8.1 - General recommendations..................................................................................................................................... 67
8.2 - Maintenance protocol............................................................................................................................................. 68
8.2.1 - Checking the system water pressure and any leaks................................................................................. 68
8.2.2 - Checking the gas pressure and any leaks ................................................................................................ 68
8.2.3 - Checking the condition of the safety valve................................................................................................ 68
8.2.4 - Checking the condition of the safety and control devices ......................................................................... 69
8.2.5 - Checking the condition of the electrical system ........................................................................................ 69
8.2.6 - Checking the operation of the main switch ............................................................................................... 69
8.2.7 - Checking the correspondence of the adjusted temperatures in the heating and domestic hot water systems 69
8.2.8 - Checking if the device is triggered in the event of gas failure................................................................... 69
8.2.9 - Checking the condition of the air intake and ue gas outlet ducts ............................................................ 69
8.2.10 - Checking the ignition and detection electrodes ..................................................................................... 69
8.2.11 - Checking the condition of the air vent valves.......................................................................................... 69
8.3 - Dismantling of casing and access to internal components .................................................................................... 70
8.4 - Dismantling the burner fan assembly..................................................................................................................... 71
8.5 - Cleaning the burner and the primary heat exchanger (ue gas side) .................................................................... 71
8.6 - Correct positioning of ignition and ionisation electrodes ....................................................................................... 72
8.7 - Dismantling the ignition and detection electrodes ................................................................................................. 72
8.8 - Dismantling and replacing the gas valve................................................................................................................ 73
8.9 - Cleaning the condensate conveyor siphon ............................................................................................................ 74
8.10 - Removing the ow meter ..................................................................................................................................... 75
8.11 - Removing the safety valve ................................................................................................................................... 75
8.12 - Removing the air vent valve................................................................................................................................. 76
8.13 - Replacing the pump motor ................................................................................................................................... 76
8.14 - Removing the central heating circuit pressure sensor ......................................................................................... 76
8.15 - Emptying the boiler .............................................................................................................................................. 77
8.16 - Minimum and maximum power ........................................................................................................................... 77
8.17 - Checking the ionisation current............................................................................................................................ 78

4
MYDENS 60 COSMOGAS
CONTENTS
8.18 - Checking combustion efciency........................................................................................................................... 78
8.19 - Water temperature measurement sensors........................................................................................................... 78
8.20 - Outdoor temperature sensor ................................................................................................................................ 79
8.21 - Wiring diagram ..................................................................................................................................................... 80
9 - TECHNICAL DATA ........................................................................................................................................82
10 - COMMAND MENU DIAGRAM....................................................................................................................84
11 - EU DECLARATION OF COMPLIANCE ......................................................................................................85
12 - PRODUCT FICHE.......................................................................................................................................86

5MYDENS 60
COSMOGAS
If you smell gas
1. - Close the gas cock.
2. - Ventilate the room.
3. - Do not switch on any electric device, including a telephone.
4. - From another room, immediately call a professionally
qualied technician or the gas supply company. Call the
Fire Service if the former are not available.
If you can smell combustion products
1. - Switch the appliance off.
2. - Ventilate the room.
3. - Call a professionally qualied technician.
Explosive or highly ammable products
Do not store or use explosive materials or highly ammable
materials such as paper, solvents, paints, etc. in the room
where the appliance is installed.
Installation, modications
The gas appliance must be installed, calibrated and
modied by professionally qualied staff, in compliance with
national and local regulations, as well as the instructions
in this manual.
Incorrect installation or poor maintenance can cause
damage or injury to persons, animals or objects, for which
the manufacturer cannot be deemed liable.
The appliance outlet must be connected to a exhaust gases
evacuation pipe. Failure to comply with this regulation leads
to serious risks for the safety of persons and animals.
A domestic hot water temperature exceeding 51°C can
cause permanent damage or injury to persons, animals
and objects. In particular, protect children, the elderly and
people with disabilities against any possible risks of scalds,
by inserting devices that limit the usage temperature of the
DHW to users.
The parts conducting the ue gas must not be modied.
Do not obstruct the ends of the intake/outlet pipes.
Do not leave parts of the packaging and any replaced parts
within the reach of children.
Seal the adjustment devices after every calibration.
In agreement with the provisions for use, the user must
keep the installation in good working order and guarantee
reliable and safe operation of the appliance.
The user must have maintenance performed on the appliance
by a professionally qualied technician in compliance with
national and local regulations and this manual.
We would also highlight the benet of an annual scheduled
maintenance contract with a professionally qualified
technician.
Before performing any cleaning or maintenance operations,
disconnect the boiler from the mains power supply and
gas, activating the relevant isolation devices up-stream
from the boiler.
After having performed any cleaning or maintenance
operations, make sure that all internal parts of the appliance
are dry before re-connecting the electric power supply.
This appliance is not intended for use by persons (including
children) with reduced physical, sensory and mental
capabilities or a lack of experience or knowledge, unless
they are supervised or have been instructed on use of the
appliance by a person responsible for their safety.
This manual is an integral and essential part of the product
and must be retained carefully by the user for future
consultation. If the appliance needs to be transferred or
if you should move and leave the unit to another user,
always ensure that this manual remains with the new user
and/or installer.
Any options or kits added later must be original Cosmogas
products.
This appliance must be used only for the expressly declared
purpose: heating water for closed circuits intended for
centrally heating rooms for civil and domestic use, and
producing domestic hot water for civil use.
Any contractual and non-contractual liability on the part
of the manufacturer is excluded for damage caused by
installation errors or usage errors and, in all cases, following
a failure to comply with the instructions given by the
manufacturer or with applicable national and/or local laws.
For safety reasons and to safeguard the environment, the
packaging components must be disposed of in the relevant
separate waste collection centres.
In case of breakdown
In the event of a fault and/or poor operation of the appliance,
disconnect it and do not attempt to carry out any repairs.
Contact a professionally qualified technician only. If
components need to be replaced, these must be original spare
parts. Failure to comply with the above may jeopardise the
safety of the appliance.
Professionally qualied technicians.
A ‘professionally qualied technician’ means a person with
specic technical skills in the sector of central heating system
components and the production of domestic hot water for
sanitary and civil uses, electric installations, and systems for
the use of combustible gas. Such people must have the skills
envisaged by the law.
Technical drawings
All the drawings shown in this manual relating to electrical,
hydraulic or gas installation systems must be understood to
be purely illustrative. All the safety devices, auxiliary devices
as well as the diameters of the electrical, hydraulic and gas
pipes, must always be checked by a professionally qualied
technician, to make sure they satisfy the applicable laws and
regulations.
1.1 - National installation
laws and regulations
- Rules regarding the prevention of res issued by the re
service
- Ministerial Decree of 01/12/75
- Law of 09/01/91 n°10 as amended
- Presidential Decree n° 412 dated 26/08/93
- Ministerial Decree of 12/04/96
- Presidential Decree n° 551 dated 21/12/99
- Legislative Decree n°192 of 19/08/05
- Legislative Decree n°311 of 29/12/06
- Ministerial Decree of 22/01/2008 n°37
- Law of 03/08/13 n°90
- Legislative Decree n°102 of 04/07/14
- Ministerial Decree of 26/06/15
- CEI standard 64-8
- INAIL compilation R
1 - GENERAL SAFETY WARNINGS

6
MYDENS 60 COSMOGAS
2 - GENERAL INFORMATION
2.1 - Presentation
Congratulations! You have purchased one of the best products on the market.
Each individual part is proudly designed, manufactured, tested and assembled within the COSMOGAS
facilities, thus guaranteeing the best quality control.
MYDENS XXY
“60C” = Boiler with maximum heat input of 57.8 kW with built-in pump;
“60A” = Boiler with maximum heat input of 57.8 kW without built-in pump;
Internal wall-mounted gas condensing boiler with premixed burner with low
emissions of pollutants.
2.2 - Overview of models
2.3 - Accessories included
The boiler is supplied with the following accessories:
Quantity No. Description Code Figure
N° 1 GAS CONVERSION KIT 62630277
N° 1 CONNECTIONS KIT
(including appliance wall support KIT, external sensor and storage tank sensor) 62629830

7MYDENS 60
COSMOGAS
2.4 - Manufacturer
COSMOGAS srl
Via L. da Vinci 16
47014 - Meldola (FC) Italy
Tel. [phone]
Fax. [phone]
www.cosmogas.com
[email protected]
2.5 - Meaning of symbols used
WARNING!
Danger of electric shocks. If these warnings are not heeded it
can jeopardise correct operation of the boiler or cause serious
injury or damage to people, animals or things.
WARNING!
Generic danger. Failure to comply with these warnings may
jeopardise the working order of the appliance or cause serious
damage or injury to persons, animals or things.
Important indication symbol
2.6 - Maintenance
A regular annual maintenance check on the appliance is
advised for the following reasons:
- to maintain high efciency and manage the central heating
system economically (with low fuel consumption);
- to achieve a high level of operating safety;
- to maintain a high level of environmental combustion
compatibility;
Offer your customer a scheduled maintenance contract.
2.7 - Disposal
The crossed wheelie bin symbol means that the product
must not be thrown away in the ordinary rubbish bin (i.e. in
with “mixed urban rubbish”). It must be dealt with separately,
in order to undergo suitable operations for it to be reused or
treated to remove and safely dispose of any substances that
are dangerous for the environment. This will enable all the raw
materials to be recycled. The user is responsible for getting
rid of the boiler at the end of its life, delivering it to a recycling
centre run by the local authority or city hygiene companies,
or, when he/she buys a new boiler, giving the product that has
been replaced to the dealer, who is obliged to take it under
the terms of EU Directive 2012/19/EU.
For further information regarding correct decommissioning
of these appliances, users can contact the public service in
charge or retailers.
2 - GENERAL INFORMATION

8
MYDENS 60 COSMOGAS
1 - Command and control board
2 - Electric connections board
3 - ----------
4 - Water ow rate gauge
5 - ----------
6 - Circulation pump unblocking screw
7 - Circulation pump (only model “C”)
8 - Detection electrode
9 - Primary heat exchanger
10 - ----------
11 - Air vent valve
12 - Air intake and exhaust gases outlet
13 - Support attachments
14 - Sparks generator
15 - Ignition cables
16 - Back ue preventer valve
17 - Air inlet manifold
18 - Air/gas manifold
19 - Gas valve
20 - ----------
21 - Front casing
22 - Display
23 - Control panel
3 - MAIN COMPONENTS
Figure 3-1 – Boiler internal components
4
13
23
22
12
21
38
19
7
16
17
2
18
1
8
14
15
11
9
020005.01.002

9MYDENS 60
COSMOGAS
24 - Flue gas temperature sensor (Par. 1006) and ue gas
temperature fuse
25 - Front casing couplings
26 - Double supply temperature sensor (Par. 1001 and
1005)
27 - Central heating circuit pressure sensor
28 - Return temperature sensor (Par. 1007)
29 - Condensate collection tank
30 - Safety valve
31 - Fan
32 - Air/gas mixing group
33 - Condensate outlet siphon
34 - Burner
35 - Burner pilot light
36 - LH ignition electrode
37 - RH ignition electrode
38 - Primary heat exchanger temperature fuse
3 - MAIN COMPONENTS
Figure 3-2 – Boiler internal components
25
29
24
36
37
32
31
27
28 35
26
30
33
34
02.0005.01.003

10
MYDENS 60 COSMOGAS
Figure 4-1 Key:
1 = Boiler
2 = Combustion agent air inlet
3 = Flue gas outlet
4 = Flue gas temperature sensor (Par. 1006) and ue gas
temperature fuse
5 = Sealed chamber
6 = ----------
7 = Collection pipe for any water coming from the combustion
agent air inlet pipe
8 = Supply temperature sensor (Par. 1001)
9 = Delivery temperature safety sensor (Par. 1005)
10 = Burner
11 = Stainless steel VRC type heat exchanger
12 = Fan
13 = Return temperature sensor (Par. 1007)
14 = Condensate collection siphon with sediment decanter
15 = Air/gas mixer
16 = Pneumatic gas valve
17 = Central heating circuit water pressure sensor
18 = Circulation pump *
19 = Central heating circuit supply
20 = Gas inlet
21 = Central heating circuit return
22 = Collector for condensate drain and safety valve
23 = Central heating system
24 = Air vent valve
25 = Safety valve
26 = Water ow rate gauge
50 = Primary heat exchanger temperature fuse
* Only on model C
4 - OPERATION
Figure 4-1 – Hydraulic layout
MYDENS 60A
MYDENS 60C

11 MYDENS 60
COSMOGAS
4.1 - Operation and intended
use of the appliance
This product is a gas condensing boiler, designed for the
production of central heating. It can also be used for the
production of domestic hot water but must be connected to
an appropriate storage tank (see gure 4-6).
Carry out the adjustment between the boiler and the
system, bearing in mind the characteristic residual head
curve (see g. 4-2).
4.1.1 - Modulating pump
The MYDENS 60Aboiler is expressly manufactured without an
internal pump in order to give the installer the option of being
able to connect any modulating pump. The only preventative
measure to take is to insert a by-pass valve (see gure 4-4,
detail “35”) through which, in any operating situation, the
boiler is always guaranteed a minimum water circulation of
600 l/h. The characteristic curve of the modulation range of
the modulating pump provided by us is shown in gure 4-2.
4.1.2 - Hydraulic separator
If the system must be served by a water ow rate that is
higher than the pump can deliver, a hydraulic separator must
be inserted between the boiler and the system (see gures
4-5 and 4-6, detail “20”).
4.1.3 - Production of domestic hot water
For the production of domestic hot water a storage tank must
be connected following the diagram in gure 4-6.
The temperature of the domestic hot water is adjusted
following the procedure in section 7.7.
4.1.4 - Types of system
The following types of systems can be set up depending on
the model:
With this boiler you can create a system for central heating
only (see gures 4-4 and 4-5) or a system for central heating
and the production of domestic hot water (see gure 4-6). In
both cases, the central heating system can be at high or low
temperature (See section 5.9 for adjusting the boiler).
4.2 - Precautions for installation
For the boiler to work well, respect the following directions:
This appliance must be connected to a central heating
system and if need be to a domestic hot water distribution
network, compatible with the features, performance and
power of the appliance itself.
Check gure 5-1 concerning the minimum safety distances
for installation and future maintenance.
4 - OPERATION

12
MYDENS 60 COSMOGAS
4.3 - Characteristic residual head
curves at the central heating system
The residual head at the MYDENS model boiler
connections with the standard modulating pump is given as
a graph in gure 4-2.
The modulation range (detail “x”) can be checked using the
graph in gure 4-2.
4 - OPERATION
Figure 4-2 KEY
X = Modulation range
Figure 4-2 – Residual head for MYDENS 60C with modulating pump (as standard)

13 MYDENS 60
COSMOGAS
Figure 4-3 - Hydraulic resistances of MYDENS “A” boiler
4 - OPERATION
4.4 - Characteristic curve
of head losses
The MYDENS 60A boiler does not have a circulation pump.
When deciding on the size of the pump to be used, the
designer must consider the system’s hydraulic resistances
and the hydraulic resistances of the boiler itself. For this
purpose the hydraulic resistances of the boiler are shown in
gure 4-3 in the form of a graph.

14
MYDENS 60 COSMOGAS
4 - OPERATION
Figure 4-4 - Example of basic connection diagram KEY to gures 4-4 and 4-5 1 MYDENS 60 boiler 2 INAIL safety valve 3 INAIL pressure gauge 4 INAIL thermometer 5 INAIL maximum safety pressure switch 6 INAIL safety thermostat 7 Gas cock 8 INAIL Gas isolation valve 9 INAIL basin 10 Gas inlet 11 Expansion tank 12 Microbubble separator
Figure 4-5 - Example of connection diagram with hydraulic separator
13 External sensor (supplied as standard) 14 Filter 15 Electric power supply 16 Low or high temperature heating system 17 System water supply 18 Cold DHW 19 Central heating circuit pump 20 Hydraulic disconnector 21 Air vent valve 23 Condensate neutraliser 24 INAIL minimum safety pressure switch 35 - By-pass valve 36 - Circulation pump (to be used with MYDENS 60A models) 37 Room thermostat or equivalent system

15 MYDENS 60
COSMOGAS
4 - OPERATION
1 MYDENS 60 boiler 2 INAIL safety valve 3 INAIL pressure gauge 4 INAIL thermometer 5 Maximum pressure safety switch INAIL 6 INAIL safety thermostat 7 Gas cock 8 INAIL Gas isolation valve 9 INAIL basin 10 Gas inlet 11 Expansion tank 12 Microbubble separator 13 External sensor (supplied as standard) 14 Filter 15 Electric power supply 16 Condensate neutraliser 17 Air vent valve 18 Cold DHW 19 Central heating circuit pump 20 Hydraulic disconnector 21 Isolation valve 22 Check valve 23 Delivery to the central heating system 24 Central heating system return 25 Stopper for dirt outlet 26 Central heating system mixer valve 27 System outlet 28 Storage tank load pump 29 System load assembly 30 Storage tank safety valve 31 Storage tank temperature sensor (supplied as standard) 32 Domestic hot water circuit expansion tank 33 Domestic hot water outlet 34 INAIL minimum safety pressure switch 36 - Circulation pump (to be used with MYDENS 60A models) 37 Room thermostat or equivalent system
Figure 4-6 - Example of connection diagram with hydraulic separator and storage tank

16
MYDENS 60 COSMOGAS
5.1 - Opening the package
The boiler is supplied in a cardboard package. To open it,
follow the instructions given on the package’s closing aps.
5.2 - Dimensions and minimum
distances to be observed
For both installation and maintenance, it is necessary to leave
free spaces around the boiler, as shown in gure 5-1.
5.3 - Choosing where to
install the appliance
WARNING! The appliance must be installed
exclusively on a solid, vertical wall, which can bear the
weight.
Before installing the appliance, the central heating system
and, if necessary, the domestic hot water system must be
washed thoroughly in order to remove any residues or
impurities which could compromise the working order of
the boiler.
This boiler is not designed to be installed in the open air;
it must not be exposed to temperatures below zero and
above 50°C. Choose a place sheltered from the weather
and from frost.
This appliance must be installed in a place where water
leakages from the appliance itself, from the joints between
the pipes or from any drainage from the safety valve,
cannot cause damage to materials or items below it.
The appliance must be installed inside your home, or
otherwise protected from atmospheric agents such as rain,
wind, sun, and especially frost.
Choose the room and suitable position for installation,
taking into account the following factors:
- connection of the ue gas outlet/air intake pipes;
- connection of the gas supply pipe;
- connection to the water supply;
- connection to the central heating system;
- connection to domestic hot water system (where present);
- electric connection;
- connection to the drain for the condensate produced by
the boiler;
- electric connection of the room thermostat;
- possible connection to safety valve outlet;
- connection to the outdoor temperature sensor (where
applicable);
1 - Central heating delivery 1” 1/2
2 - 3/4" gas inlet
3 - Central heating return 1” 1/2
4 - Flue gas outlet / Air intake
5 - Support brackets
5 - INSTALLATION
Figure 5-1 – Minimum safety distances
Figure 5-2 – Boiler dimensions and attachments
centre-to-centre distances

17 MYDENS 60
COSMOGAS
5 - INSTALLATION
5.4 - Unit assembly
Refer to gure 5-3:
1.- mark the holes for the plugs and hydraulic ttings on the
wall, checking they are square;
2.- make holes “A” and insert the wall plugs “B”;
3.- make the boiler hydraulic and gas connections;
4.- hang the boiler on the plugs “C”;
5.- make the hydraulic connections.
5.5 - Delivery and return
WARNING! COSMOGAS is not liable for any
damage caused by incorrect use of additives in the
central heating system.
WARNING! The system after the appliance must
be made with materials that resist temperatures up to
97°C and pressure of 3 bar. Otherwise (e.g. with plastic
piping), the system must be tted with the relevant
protection and safety devices.
Before connecting the central heating pipes, wash the
system thoroughly to eliminate any waste (hemp, radiators
casting sand, etc.), which could damage the appliance. This
must also be performed if the appliance is replaced.
Figure 5-2 shows the positioning of the supply and return
ttings.
Install a metal mesh lter on the return pipe in order to
trap any system residues before they return to the boiler.
Do not use the appliance to introduce any type of
additive into the system.
Figure 5-3 – Support plugs

18
MYDENS 60 COSMOGAS
5 - INSTALLATION
to nd, especially when the leak is minimal (in winter leaks
from radiator valves sometimes are not visible because they
are dried by the heat produced by the radiator or appliance).
These micro-leaks do, however, allow air to get into the
system. The main points that micro-leaks can develop are at
the joints and, in particular, on the intake side of the pump (air
vent valve, seals with O-rings, ll valves). In these cases, to
avoid damage, the system must be protected with a suitable
corrosion inhibitor.
5.6.2 - For correct operation of the system
make sure that:
1) the system has no leaks or at least the most obvious leaks
have been repaired;
2) if there is an automatic lling system, a litre counter must
have been installed so as to know the exact quantity of any
leaks;
3) lling the system and relling is done with softened water
so as to reduce its overall hardness. The water must also be
conditioned in order to keep the pH within the threshold set
so as to avoid corrosion;
4) Both on new systems and system replacements there must
be efcient systems to get rid of air and impurities; lters,
micro-impurity separators and micro air bubble separators;
5) Avoid discharging water from the system during normal
maintenance operations, even if it is apparently insignicant
quantities: for example when cleaning lters, equip the system
with the relevant isolation valves up and down stream from
the lter itself;
6) Always carry out an analysis of the system water before
opening communication between a new boiler and the system,
to establish whether the chemical and physical properties of
the water indicate the need to carry out complete emptying
of the system, the use of the water already in the system
or chemical washing of the system, using mains water with
the addition of a detergent, when there is a suspicion that
the system may be dirty or particularly blocked up, and the
subsequent relling with new treated water.
If the analysis of a sample of water that will be used to ll the
system shows the following values:
- 7.5 < pH < 9.5
- Ca++ + Mg++ : <0.5°f (Total hardness)
- OH + 1/2 C03: from 5 to 15°f
- P205: from 10 to 30 mg/l
- Na 2S03: from 20 to 50 mg/l
then you can proceed with lling. If the properties are different,
an inhibitor must be used.
5.6 - Water supply
Check the water mains connection pressure and if necessary
install a suitable pressure reducer.
WARNING! The connection of the central
heating system (and therefore the heating unit) to the
water mains must be completed with the insertion
between them of a device that prevents backows to
the drinking water system, as required by the anti-
pollution safety regulations in force.
5.6.1 - Recommendations on
characteristics of water in the system
Filling the central heating system is an extremely delicate
operation that should not be underestimated, either in cases
of just replacing the heat generator or in when a new appliance
is installed. Incorrect assessment of the characteristics of the
system’s water can lead, in some cases, to damage to the
system and heating unit. A system is almost never perfectly
sealed; sometimes there may be water leaks and oxygen can
also get in; both these phenomena cause damage.
Among the parameters that can have a negative impact on the
lifetime of a system, the following are the main ones:
- The simultaneous presence of different metals (copper, brass,
steel and aluminium) which, in an aqueous environment, give
rise to galvanic corrosion.
- The presence of free oxygen, due to air inltration which may
occur near to joints or seals, constitutes a typical corrosive
agent, particularly active at temperatures between 50 and
70° C.
- Water leakage, which leads to frequent rells, can cause
corrosion or limescale, depending on the type of water
available for the llings. In all cases all of the leaks (and
relative rells) must be kept under control, especially when an
automatic lling system is installed. In this case it is denitely
recommended that a meter be installed which can indicate
the quantity of water replenished.
Natural or added impurities in the water. A lot of drinking
water can contain concentrations, which may be signicant,
of chlorides and sulphates that can increase the speed of
corrosion of metallic surfaces. Other undesirable components
could have been introduced into the system before or during
installation (building materials, metallic chips, shavings,
grease, deposits and dirt in general). Residues from welding
can also cause corrosion, both in new systems and after
modications and repairs. In old systems planned to work
with radiators, characterised by pipework with a very large
diameter, the water content of the system is signicant and
fosters the formation of dirt and deposits.
Dirt and Limescale The presence of black deposits (magnetite)
indicates that there is limited corrosion, however, the high
specic weight of this oxide can cause blockages that are hard
to remove, especially in the hottest areas. Limescale is due to
the hardness of the water, or to the presence of calcium and
magnesium salts. Calcium, in the form of calcium carbonate,
is deposited in the hottest areas of the system. Magnetite often
contributes to consolidating the limescale. On the other hand,
iron oxide (the water has a reddish colour) is an indicator of
corrosion from oxygen.
Frequent leaks. Where there are frequent leaks the hydrogen
and/or air accumulate on the top part of the heat exchanger
and radiators, preventing full exchange of heat. When the
electrolytic corrosion process has begun, the water level in
the system is lowered, gases accumulate in the top part of the
heat exchanger and radiators. The presence of air is caused
by the fact that the system might not be perfectly sealed. A
slow drop in system pressure due to a leak is often difcult

19 MYDENS 60
COSMOGAS
5 - INSTALLATION
5.6.3 - Water treatment in domestic heating
systems
The water in domestic heating systems must always be treated
both when the boiler is replaced and when it is a new system.
All the treatment systems and chemical conditioning processes
required must be set up during the planning stage, based on
the characteristics of the unrened water, in order to obtain
water with the following characteristics:
- Appearance: clear, colourless and with no foam;
- pH: from 7.5 to 9.5;
- Conditioners: present within the concentrations laid down
by the supplier.
If the water characteristics are unknown, there is a very high
probability of running into problems such as the following:
1. LIMESCALE
1 °fr = 10mg/kg CaCO3
30° fr = 300 mg/kg CaCO3
For a system that contains 1000 litres of water at 30°f the
content of CaC03is 300 gr, which, if not suitably treated, will
be deposited on the surface of the heat exchanger (as it is
the hottest part of the system). This creates concentrated
increases in temperature and consequently causes the heat
exchanger to break.
2. CORROSION
As a rule corrosion is fostered by the presence of oxygen,
by contact between different metals, or by the presence of
chlorides.
3. DEPOSITS
These are insoluble organic and inorganic substances: DIRT,
RESIDUES FROM WORK.
5.7 - Heat circuit outlet
In order to avoid constantly relling with water and the resultant
introduction of oxygen and limescale, it is advisable to limit
as much as possible any work of draining the heating circuit.
5.8 - Expansion tank
WARNING! Provide the system with an
expansion tank of a suitable size, as laid out in national
and local installation regulations.
5.9 - Low-temperature systems
(or underoor heating)
WARNING! The system after the appliance must
be made with materials that resist temperatures up to
95°C and pressure of 3 bar. Otherwise (e.g. with plastic
piping), the system must be tted with the relevant
protection and safety devices.
WARNING! When installing the boiler in a low-
temperature system, set parameter 2024 to 45°C and
parameter 2023 to 20°C (see section 7.15).
With this setting, the boiler will adjust the supply to a
temperature between 20°C and 45°C. No adjustment from
the command panel (also via climate control) can supply
water at a temperature over 45°C.
WARNING! If the boiler is installed in an
underoor system made with plastic piping, all of the
necessary precautions must be taken against corrosion
due to oxygen in the water:
make sure that the system is made with plastic pipes
with oxygen permeability not exceeding 0.1 g/m3 at
40°C. Should the pipe not meet these characteristics, the
radiant panel circuit must be isolated from the boiler, via
a plate heat exchanger suitable for resisting the corrosion
generated by the oxygen dissolved in the water.
5.10 - Gas
WARNING! Do not power the appliance with
gases other than those specied.
WARNING! Check that the gas and supply
pressure are those for which the boiler has been
adjusted.
Two situations are possible:
A - the gas and supply pressure correspond to the
adjustment of the boiler. In this case, it can be
connected;
B - the gas and supply pressure do not correspond to the
adjustment of the boiler. In this case, the boiler must
be converted to the type of gas and supply pressure
corresponding to those of the supply available.
The boiler is provided with the relevant gas conversion kit.
Before installation, clean the inside of the gas supply
pipe thoroughly;
Install a shut-off cock on the gas supply pipe;
To prevent damage to the appliance gas control unit, run
a leak test at a pressure not exceeding 50 mbar;
If the gas system must be inspected at pressures over
50 mbar, turn the cock located immediately upstream
from the boiler, to isolate it from the system.
Use gure 5-2 to check the position of the appliance gas
tting. The cross-sections of the pipes in the gas supply
system must always guarantee a gas supply that is
sufcient to cover the maximum demand.

20
MYDENS 60 COSMOGAS
Figure 5-4 – Connecting the safety valve outlet
and condensate outlet
5 - INSTALLATION
5.11 - Condensate outlet
There is a siphon inside the boiler for the evacuation of
condensate (see gure 3-2, detail “33”) and to prevent
combustion products from escaping. The end of the siphon
is pipe “B” in gure 5-4. This end must be conveyed into
another, anti-odour siphon (gure 5-6, detail “G”) to prevent
bad odours returning to the environment (the anti-odour
siphon “G” is supplied on request).
Tank “A” is supplied ready assembled as shown in gure
5-4 and secured with screw “D”, outlet pipe “F” is also
installed as shown in gure 5-4.
In particular, the condensate outlet system must:
be for rooms used for residential purposes and for
ofces with more than 10 users; it can be connected
to the domestic waste disposal plant by means
of appropriate siphon with disjunction, capable of
preventing the pressurisation of the system (the siphon
is inside the boiler) and the return of bad odours from
the sewers (detail “G” in gure 5-6). If the room used
for ofce purposes has fewer than 10 users, before
connecting up the domestic waste drain, install a
condensate neutraliser (see section 9 for the acidity
value of the condensate and the quantities).
be performed with a pipe with an internal diameter equal
to or greater than 13 mm;
be installed in such a way as to prevent the liquid
from freezing; therefore pay attention to any external
sections. It is prohibited to drain into gutters or rainwater
drainpipes;
slope continuously towards the drain point; avoid high
points, which could pressurise the pipe;
5.12 - Safety valve
The appliance is protected against overpressures by a
safety valve calibrated to 3 bar (see gure 3-2 detail “30”).
The safety valve outlet (detail “C” in gure 5-4), along
with the condensate outlet (detail “B” in gure 5-4) must
be conveyed to pipe “F” (see gure 5-4) with a minimum
internal diameter of 13 mm; pipe “F” must then be taken
to the anti-odour siphon (detail “G”, gure 5-6). This drain
with a siphon is used to prevent overpressures if the
valve is opened, and it allows the user to check possible
intervention.
Pipe “F” in gure 5-6 is supplied assembled as standard
together with tank “A” in gure 5-4. The anti-odour siphon
“G” in gure 5-6 is provided on request.
WARNING! If the safety valve is not connected
to the drain, whenever the valve intervenes, it could
cause damage to persons, animals or objects.
5.13 - Plumbing and gas connections
The boiler is provided with the ttings illustrated in gure
5-5 as standard, where:
A = central heating delivery Ø 35
G = central heating return Ø 35
C = delivery tting 1” 1/2
D = return tting 1” 1/2
E = Gasket 1”1/2
Figure 5-5 – Water connections
C
A
E
D
B
020005.01.005
Figure 5-6 – Siphon funnel (on request)
F
G
020002.01.028
min10 mm
max 30 mm
C
B
A
D
G
F
E
020005.01.004