MHS Boilers Elco ADI-Nox HT Series Installation and operation manual

ADI-Nox HT Boiler
With LMS Controls
Models 105 to 950
Operating & Maintenance Manual
MHS Boilers Ltd
3 Juniper West
Fenton Way
Southfields Business Park
Basildon
Essex
SS15 6SJ
Tel: [phone]
Fax: [phone]
WWW.MHSBOILERS.COM
L349

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I
IN ND DE EX X
1. INTRODUCTION_________________________________________________________________________________ 3
2. REGULATIONS _________________________________________________________________________________ 7
3. EEC APPROVALS AND CERTIFICATIONS ___________________________________________________________ 7
4. BOILER GENERAL VIEW: DESCRIPTION OF THE COMPONENTS________________________________________ 8
5. DIMENSIONS __________________________________________________________________________________ 10
6. TECHNICAL DATA______________________________________________________________________________ 12
6.1 Models ADI HT 105 to ADI HT 400 ________________________________________________________________ 12
6.2 Models ADI HT 475 to ADI HT 950 ________________________________________________________________ 13
7. BOILER HEAT EXCHANGER _____________________________________________________________________ 14
8. POWER MODULATION AND COMBUSTION SYSTEM _________________________________________________ 14
8.1 Assembly of gas connection –air/gas inlet ________________________________________________________ 16
8.2 Air inlet filter _________________________________________________________________________________ 18
8.2.1 Optional air filter for ADI little size ______________________________________________________________ 18
9. BURNER______________________________________________________________________________________ 19
9.1 Ignition and ionization kit_______________________________________________________________________ 19
10. CONTROL PANEL - SIEMENS ___________________________________________________________________ 20
10.1 Display _____________________________________________________________________________________ 21
10.2 Programming________________________________________________________________________________ 24
10.3 Available parameters at enduser level ___________________________________________________________ 27
10.4 Boiler lockout code___________________________________________________________________________ 28
10.5 Function boiler maintenance ___________________________________________________________________ 28
10.6 Data and information visualized on the display ____________________________________________________ 28
11. CONTROL OF SEVERAL BOILERS –CASCADED SYSTEM ___________________________________________ 29
11.1 Boilers sequence included_____________________________________________________________________ 29
11.2 External control signal 0…10 V to regulate start-up and power modulation of each boiler_________________ 34
11.3 Remote Control or telecomputing __________________________________________ Error! Bookmark not defined.
12. ELECTRIC DRAWING __________________________________________________________________________ 36
12.1 Electric drawing ADI HT 105 –850 (single-phase motor) ____________________________________________ 37
12.2 Electric drawing ADI HT 950 (three-phase motor) __________________________________________________ 37
12.3 Cover of Siemens electronical board ____________________________________________________________ 39
12.4 Cable entry points____________________________________________________________________________ 39
13. HEATING CIRCUITS ___________________________________________________________________________ 40
13.1 Heating circuits basic parameters_______________________________________________________________ 42
13.2 Professional installator parameters _____________________________________________________________ 42
14. DOMESTIC HOT WATER________________________________________________________________________ 48
14.1 Basic parameters ____________________________________________________________________________ 49
14.2 Professional installator parameters _____________________________________________________________ 50
15. SAFETIES____________________________________________________________________________________ 52
16. BOILERS IDENTIFICATION LABEL _______________________________________________________________ 52
17. INSTALLATION _______________________________________________________________________________ 53
17.1 Boilers heat output ___________________________________________________________________________ 53
17.2 Lifting and transporting the boilers by a crane ____________________________________________________ 53

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17.3 Boilers room ________________________________________________________________________________ 53
17.4 GAS SUPPLY________________________________________________________________________________ 54
17.4.1 Gas pressure higher than 45 mbar_____________________________________________________________ 54
17.5 Chimneys___________________________________________________________________________________ 55
17.5.1 Chimney sizing_____________________________________________________________________________ 55
17.5.2 Flue draught stabilizer_______________________________________________________________________ 56
17.5.3 Old installation _____________________________________________________________________________ 56
17.5.4 Adjustable flue damper at the boiler flue outlet __________________________________________________ 57
17.6 HYDRAULIC INSTALLATION ___________________________________________________________________ 58
17.6.1 Data to be considered _______________________________________________________________________ 58
17.6.2 Overpressure safety valve____________________________________________________________________ 58
17.6.3 Hydraulic pressure drop _____________________________________________________________________ 59
17.6.4 Water manifold _____________________________________________________________________________ 60
17.6.5 Water quality of the installation _______________________________________________________________ 61
17.7.6 System drawings ___________________________________________________________________________ 62
17.6.7 Minimum return water temperature to boilers and system drawings _________________________________ 66
18. THE BOILER START-UP ________________________________________________________________________ 67
18.1 Before the start-up ___________________________________________________________________________ 67
18.2 Air and gas pressure switch ___________________________________________________________________ 67
18.3 The boiler control unit and operating cycle _______________________________________________________ 68
18.4 Gas/air adjustments __________________________________________________________________________ 69
18.4.1 Combustion adjustment _____________________________________________________________________ 69
18.4.2 Change of fuel: from Propane gas to Natural gas_________________________________________________ 71
19. MAINTENANCE _______________________________________________________________________________ 71
19.1 Procedure to dismantle the burner ______________________________________________________________ 71
19.2 Position of probes and sensors________________________________________________________________ 73
19.3 COMBUSTION DATA__________________________________________________________________________ 74
20. BOILER GUARANTEE__________________________________________________________________________ 75
21. APPENDIX I: LIST OF ERROR CODES ____________________________________________________________ 77
Please note that this manual is liable to changes and alterations or withdrawal without prior notice
MHS Boilers Ltd reserve the right to make modifications without notice and any changes made are not
necessarily retrospective to older models.
No company, person or entity external to MHS Boilers can modify this document.

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1. INTRODUCTION
The global trend, European and international, aims at improving energetic efficiency both in buildings and
generators, in order to reduce pollutant emissions in the atmosphere (directive SAVE, KYOTO agreement)
Carbon dioxide (CO2) is one of the greenhouse gases that remain the longest in the atmosphere. In accordance
with IEO2007, predicted CO2 emissions will be 33.9 billon tons in 2015 and 42.9 in 2030.
This is why the European campaign known as “20-20-20 in 2020” has been created, with the aim, among others, of
cutting carbon dioxide emissions by 20% by 2020.
The main characteristics of the ADI HT boiler are:
- Maximum efficiency in every kind of installations at any working temperatures.
Renovation of installations with traditional heat radiators
Domestic Hot Water (D.H.W.S.), in accordance with anti-legionella regulations.
-EEC Approval by CERTIGAZ, with 3 performance stars for its high energetic efficiency (according to the
European directive 92/42/EEC).
-Net efficiencies from 95 to 97% ref. to L.C.V.
-Boiler certified as “High temperature”: flow temperature up to 90ºC, minimum return temperature 60ºC.
-Power outputs from 104 to 905 kW.
-Maximum efficiency per year :
Boiler power modulation according to the demands of the installation.
High reduction of stop/start cycles.
Minimum heat losses due to convection/radiation through the boiler.
Inconsiderable heat losses through the chimney when the boiler is not operating.
-Gas boilers with modulating burner starting from 30% of power (depending on the installation conditions and
models).
-Burner power modulation by varying the premix air-gas flow by means of a motor fan of variable speed.
-Reduced electric consumptions per year thanks to the motor fan of variable speed for the air-gas inlet.
-Ecological combustion (“PREMIX” burner of innovative design).
NOx: about 10 ppm, CO: about 50 ppm (both referred to 3% O2).
-Boiler regulation and control adaptable to all systems available on the market:
The boiler can operate by means of its own regulation.
It can be connected to a sequence control unit in an installation with several boilers.
It can be connected to Building Manage System (B.M.S.).
It can be connected to telecomputing.
-Reduced dimensions and weight:
Boiler heat exchanger ADI HT 475 (464 kW of output) Large: 81 cm, Long: 94 cm, Weight: 460 kg.
Easy installation in boiler rooms of difficult access.
Installation in terraces (reinforcement of the structure is not required).
Space saving in boiler room (464 kW in less than 0.76 m2).

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2. General Regulations / Application / Norms and Regulations
General regulations
This documentation contains important information, which is a base for safe and reliable installation,
commissioning and operation of the Adinox Low Temperature Boiler. All activities described in this
document may only be executed by authorized companies.
Changes to this document may be effected without prior notice. We accept no obligation to adapt
previously delivered products to incorporate such changes.
Only original spare parts may be used when replacing components on the boiler, otherwise warranty will
be void.
Application
The Adinox Low Temperature Boiler may be used for heating and hot water production purposes only. The
boiler should be connected to closed systems with a maximum temperature of 100ºC (high limit
temperature); maximum set point temperature is 90ºC.
Norms and regulations
When installing and operating the boiler, all applicable norms (European and local) should be fulfilled:
• Local building regulations for installing combustion air and flue gas systems;
• Regulation for connecting the boiler to the electrical appliance;
• Regulations for connecting the boiler to the local gas network;
• Norms and regulations according to safety equipment for heating systems;
• Any additional local laws/regulations with regard to installing and operating heating systems.
− 92 / 42 / EEC Boiler efficiency directive − 90 / 396 / EEC Gas appliance directive − 73 / 23/ EEC Low
voltage directive − 89 / 336 / EEC EMC directive
− EN 656 Gas-fired central heating boilers –Type B boilers of nominal heat input exceeding 70 kW but not
exceeding 300 kW
− EN 15420 Gas-fired central heating boilers - Type C boilers of nominal heat input exceeding 70 kW, but
not exceeding 1000 kW
− EN 15417 Gas-fired central heating boilers - Specific requirements for condensing boilers with a nominal
heat input greater than 70 kW but not exceeding 1000 kW
− EN 13836 Gas fired central heating boilers - Type B boilers of nominal heat input exceeding 300 kW, but
not exceeding 1000 kW
− EN 15502-1 Gas-fired central heating boilers - Part 1: General requirements and tests
− EN 55014-1 Electromagnetic compatibility - Requirements for household appliances, electric tools and
similar apparatus Part 1: Emission
− EN 55014-2 Electromagnetic compatibility - Requirements for household appliances, electric tools and
similar apparatus Part 2: Immunity - Product family standard
− EN 61000-3-2 Electromagnetic compatibility (EMC) - Part 3-2: Limits - Limits for harmonic current
emissions (equipment input current 16 A per phase)
− EN 61000-3-3 Electromagnetic compatibility (EMC) - Part 3-3: Limitation of voltage changes, voltage
fluctuations and flicker in public low-voltage supply systems, for equipment with rated current 16 A per
phase and not subject to conditional connection
− EN 60335-1 Household and similar electrical appliances -Safety - Part 1: General requirements
− EN 50165 Household and similar electrical appliances -Safety - Part 2-102: Particular requirements for
gas, oil and solid-fuel burning appliances having electrical connections
The following Codes of Practice are also applicable: -
BS 6644 : 2011 Specification for gas fired hot water boilers of rated inputs between 70kW (net) and 1.8MW
(net) (2nd and 3rd family gases).
BS 6880:1988 Code of Practice for low temperature hot water heating systems of output greater than 45kW.
Parts 1, 2 & 3.
BS 6891:2005 + A2:2008 Specification for installation of low-pressure gas pipework of up to 35mm (R11/4)
in domestic premises (2nd family gases).
BS 7593:2006 Code of Practice for treatment of water in domestic hot water central heating systems.
BS 7671:2008 Requirements for electrical installations. IEE Wiring Regulations. Seventeenth Edition
BS EN 12828 2003 Heating systems in buildings –Design for water based heating systems.
CISBE Guide reference sections B7, B11 and B13.
CP342 Part 2: 1974 Code of Practice for centralized hot water supply.
IGE/UP/1 or 1A Gas Tightness Testing & Purging of Commercial Industrial Gas Installations
IGE/UP/2 Gas installation pipework, boosters and compressors on Industrial and Commercial premises.
IGE/UP/4 Commissioning of gas fired plant on industrial and commercial premises.
IG/UP/10 edition 3 Installation of gas appliances in Industrial and Commercial premises.

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Part 1: Flued appliances.
Through their unique construction, the Adinox Low Temperature Boiler range of central heating units are
renowned for their:
- High thermal output
- Environmental-friendliness (they meet the most stringent environmental conditions)
- Low weight and compact size
- Durability
- Low noise level
- Broad control range
- Can be supplied in a wide range of models
Through active and market oriented research, MHS Boilers Ltd is in a position to offer solutions for the
most challenging heating requirements.
The Supplier
MHS Boilers Ltd are proud to supply and technically support the Adinox Low Temperature Boiler Range of
boilers throughout the United Kingdom. For advice or more information please contact your local sales
representative or our head office via 01268 546700. or via our website www.mhsboilers.com
This Document
The present documentation has been prepared with the following target groups in mind:
The technical consultant
The installer
The maintenance technician
The User
MHS Boilers Ltd has opted to make the technical documentation as comprehensive as possible in the form
of this book, in order to ensure that these target groups have all the information they need. As the supplier
we would be happy to help you in connection with any additional information that you may require. This
document covers the following aspects relating to the boilers:
General description
Technical specifications
Requirements for design and installation
Maintenance instructions
The operating instructions for the user have been affixed to the appliance itself.
Service
For commissioning and assistance in maintenance matters, please contact the Technical Services
Department via 01268 546772
General restrictions
MHS Boilers Ltd products should always be used, installed and maintained in accordance with the
statutory requirements, specifications and standards applicable to these installations. All the data,
information and suggestions concerning its products provided by MHS Boilers Ltd are based on careful
study. However, the use, installation and operation of the same are outside the control of MHS Boilers Ltd
and neither MHS Boilers Ltd nor any other organisations associated with it, accept any liability for the
same.

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2. REGULATIONS
The installation must be designed and realized by qualified professionals in accordance with the current regulations
referring to gas, air venting, flues evacuation, electricity, safeties, fire prevention, etc.
The boiler maintenance must be realized following the instructions of the manufacturer’s technical manual and with
a minimum regularity as indicated by the current regulations.
3. EEC APPROVALS AND CERTIFICATIONS
ADI-Nox boilers, model ADI HT, are certified as follows:
MODEL
ADI HT
105 to 400
475 to 750
850 to 950
GAS BOILERS
DIR. 90/396/EEC
1312CL5484
(AND EFFICIENCY DIR.
92/42/EEC)
1312CL5487
1312BQ4283
The European Directive of Boilers Efficiency, dir. 92/42/EEC, only applied to boilers from 4 to 400 kW.

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4. BOILER GENERAL VIEW: DESCRIPTION OF THE COMPONENTS
A
Boiler heat exchanger (higher collector)
B
Flanges (boiler heat exchanger –burner –air/gas fan)
C
Ignition-ionization kit
D
Flame indicator
E
Motor fan (variable speed)
F
Fan
G
Venturi for air inlet and mix with gas
H
Gas shut-off valve
J
Boiler control unit and power modulation
L
Hot water flow
M
Hot water return
N
Flues outlet
P
Gas connection
Q
Air pressure switch
R
Air filter
S
Ignition transformer
T
Gas pressure switch
U
Pressure sensor
V
Air vents (manual)
Models ADI HT 105 to 200 (view from above):
(B)
(D)
(F)
(E)
(C)
(S)
(Q)
(H)
(P)
(T)
(U)
(L)
(M)
(V)
(V)

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Models ADI HT 250 and higher:
(A)
(C)
(D)
(B)
(J)
(H)
(G)
(F)
(E)
(R)
(S)

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5. DIMENSIONS
129b 9a
8
7
129b 9a
8
7
AA
4
6
5
AA
45
6
LA
FF
AL
LF
L2
L1
AL
GL GL
245 205
HF HA HG
SB
H
HF HAHG H
SB
A
ADI
HT
A
AA
AL
F (7)
H
HA
HF
HG
L1
L2
LA
LF
GL
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
105
350
185
82.5
150
1110
774
198
915
595
510
66
121
151.5
130
450
185
112.5
150
1110
774
198
963
595
510
66
121
134.3
150
450
185
112.5
150
1110
774
198
963
615
530
66
121
134.3
200
450
185
112.5
150
1110
774
198
963
635
546
66
121
134.3
250
660
305
177.5
175
1583
937
403
1156
940
775
61
134
217.3
275
660
305
177.5
175
1583
937
403
1156
940
775
61
134
217.3
325
810
360
225
250
1583
936
445
1156
940
775
61
134
292
400
810
360
225
250
1583
936
445
1190
940
775
61
134
249.3
475
810
360
225
250
1583
936
445
1190
940
775
61
134
249.3
(*) Attention: Heights H, HG, HA, HF, without taking into consideration the increase due to the silent-block feet
supplied with the boiler (dimension “SB”).
Note: data in the present document are liable to changes without prior warning.
L1 L2
12 9b 9a
AL
AA
F
7
4
6
5
A
LF
LA
GL
HF HA HG
H
SB
ADI HT
250 - 475
ADI HT 105
ADI HT 130-150-200

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Gas connection: the installation company must install a female 3-pieces coupling, for an easier dismantling and
maintenance of the boiler.
Add gas filter.
ADI HT 550 - 950
L2
L1
SB
LF
HF
12
9b
9a
8
7
F
AA
4 5
HA
H
HG
ALA AL
GL
6
ADI
HT
A
AA
AL
F (7)
H
HF
HA
HG
L1
L2
LA
LF
GL
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
550
1040
400
320
350
1628
487
1060
1396
940
775
82
140
360
650
1040
400
320
350
1628
487
1060
1396
940
775
82
140
360
750
1040
400
320
350
1628
487
1060
1396
940
775
82
140
360
850
1040
400
320
350
1658
487
1063
1393
1083
918
60
122
359
950
1040
400
320
350
1658
487
1063
1393
1083
918
60
122
359
(*) Attention: Heights H, HG, HA, HF, without taking into consideration the increase due to the silent-block feet
supplied with the boiler (dimension “SB”).
Note: data in the present document are liable to changes without prior warning.
ADI HT
4-5
6
9
12
Diam.
Diam.
Diam.
Diam.
105
2", threaded
3/4"
3/4”
½” F
130
2", threaded
1"
3/4”
½” F
150
2", threaded
1"
3/4”
½” F
200
2", threaded
1"
3/4”
½” F
250
2 ½", to be flanged (PN 6)
1"1/4
1”1/2
½” M
275
2 ½", to be flanged (PN 6)
1"1/4
1”1/2
½” M
325
2 ½", to be flanged (PN 6)
1"1/4
1”1/2
½” M
400
2 ½", to be flanged (PN 6)
1"1/4
1”1/2
½” M
475
2 ½", to be flanged (PN 6)
1"1/4
1”1/2
½” M
550
4", to be flanged (PN 10)
1"1/4
1”1/2
½”M
650
4", to be flanged (PN 10)
1"1/4
1”1/2
½” M
750
4", to be flanged (PN 10)
1"1/4
1”1/2
½” M
850
4", to be flanged (PN 10)
1"1/4
1”1/2
½” M
950
4", to be flanged (PN 10)
1"1/4
1”1/2
½” M
Legend
Concept
4
Hot water flow
5
Hot water return
6
Gas connection (female)
7
F
Flues outlet (connection to
chimney)
8
Anti-vibration supports
9
Boiler water draining (female-
threaded sleeve)
12
Draining of condensed products
(female or male-threaded sleeve)
13
Control panel

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6. TECHNICAL DATA
6.1 Models ADI HT 105 to ADI HT 400
CONCEPT
Units
105
130
150
200
250
275
325
400
Power output
Maximum power
(average water
temp: 70ºC)
kW
104
130
149.3
190
230
262
322
380
Power output
Minimum power
(average water
temp: 60ºC)
kW
31.9
40
45.7
58.5
70.3
80.1
98.4
116
Power input
Maximum
kW
109.6
138
157.2
200
242.3
270
334
396
Minimum
kW
32.9
41.4
47.2
60
72.7
81
100.2
118.8
Natural Gas
Gas flow Max.
m3/h
10.2
12.8
14.6
18.6
22.5
25.1
31
36.8
(G20)
Flues flow
m3/h
238
300
341
434
550
614
759
899
Flues Residual
Press.
Pa
18.9
64.8
90
67.5
54
70.8
90
90
Boiler weight without water
kg
110
112
123
139
330
350
440
445
Water capacity
litres
30
30
33
36
76
85
99
106
Max. water pressure
bar
5
5
5
5
5
5
5
5
Water
ΔT = 10ºC
m3/h
8.9
11.2
12.8
16.3
19.8
22.5
27.7
32.7
flow
ΔT = 12ºC
m3/h
7.5
9.3
10.7
13.6
16.5
18.8
23.1
27.2
rate
ΔT = 15ºC
m3/h
6
7.5
8.6
10.9
13.2
15
18.5
21.8
Electric
consumption
At max. output
W
134
182
222
129
201
177
342
445
At min. output
W
24
31
41
26
36
22
60
79
Maximum
consumption
W
255
268
282
256
314
259
342
445
Supply
V
1x230 V
1x230 V
1x230 V
1x230 V
1x230 V
1x230 V
1x230 V
1x230 V
Natural gas L.C.V. = 10.757 kW/m3 (38.728 MJ/m3). Natural gas pressure: min. 15 mbar / max. 45 mbar.
Propane gas = CONSULT
Electric supply to the boiler: 230 V, 50 Hz, single-phase and ground.
The electric protection of each boiler must be prepared considering the maximum value between the electric
consumption at the start-up and the electric consumption at the maximum power output.
ADI HT 105 to ADI HT 400: modulating power from 30%.
Minimum return water temperature to the boilers: 60ºC.
Note: data in the present document are liable to changes without prior warning.

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6.2 Models ADI HT 475 to ADI HT 950
CONCEPT
Units
475
550
650
750
850
950
Power output
Maximum power
(average water
temp: 70ºC)
kW
464
545
616
695
804
905
Power output
Minimum power
(average water
temp: 60ºC)
kW
141.6
166.9
187.7
211.1
244.5
367.7
Power input
Maximum
kW
483.3
563.6
638.3
720.2
829
942.7
Minimum
kW
145
169.1
191.5
216.1
249
377.1
Natural Gas
Gas flow Max.
m3/h
44.9
52.4
59.3
67
77.1
87.6
(G20)
Flues flow
m3/h
1098
1170
1321
1491
1771
2014
Flues Residual
Press.
Pa
90
69
72
75
180
270
Boiler weight without water
kg
460
480
485
485
545
545
Water capacity
litres
118
120
120
120
164
164
Max. water pressure
bar
5
5
5
5
5
5
Water
ΔT = 10ºC
m3/h
39.9
46.9
53
59.8
68.8
77.8
flow
ΔT = 12ºC
m3/h
33.3
39.1
44.1
49.8
57.3
64.9
rate
ΔT = 15ºC
m3/h
26.6
31.2
35.3
39.8
45.9
51.9
Electric
consumption
At max. output
W
727
668
859
1165
1185
1850
At min. output
W
81
86
115
124
132
329
Maximum
consumption
W
727
668
859
1165
1185
1850
Supply
V
1x230 V
1x230 V
1x230 V
1x230 V
1x230 V
3x380 V
Natural gas L.C.V. = 10.757 kW/m3 (38.728 MJ/m3). Natural gas pressure: min. 15 mbar / max. 45 mbar.
Propane gas = CONSULT
Electric supply to the boiler:
ADI HT 475 –850: 230 V, 50 Hz, single-phase and ground.
ADI HT 950: 380 V, 50 Hz, three-phase and ground.
ADI HT electric current
Maximum power
Minimum power (40%)
ADI HT 950
2.82 amp
0.36 amp
The electric protection of each boiler must be prepared considering the maximum value between the electric
consumption at the start-up and the electric consumption at the maximum power output.
ADI HT 475 to ADI HT 850: modulating power from 30%.
ADI HT 950: modulating power from 40%.
Minimum return water temperature to the boilers: 60ºC
Note: data in the present document are liable to changes without prior warning.

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7. BOILER HEAT EXCHANGER
The boiler heat exchanger (flues-water) is made of steel.
The boiler heat exchanger consists of 2 water collectors,
an upper one and a lower one, connected by means of
multiple vertical tubes forming the combustion chamber.
The vertical tubes generate a big heat transfer surface that
uses the sensible heat of the flues.
During the manufacturing process, the boiler is subjected
to a strict quality control, realized through a process of
three leak tests: one with penetrant liquids, another one
with air pressure and the last one with water pressure.
The boiler heat exchanger is insulated.
Several manual air vents are installed in the higher part of
the boiler for the air venting of the boiler.
Front and rear view: models ADI HT 200 and lower Front and rear view: models ADI HT 250 and higher
8. POWER MODULATION AND COMBUSTION SYSTEM

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12
11
7
15
1
5
13
15
5
11
14 67
3
2
8
9
4
10
NOTE: this is a guide diagram; according to the model, the position of electrodes, pilot flame, motor fan and gas
shut-off valve can vary.
Gas filter in models ADI HT 850 and 950:
In these models, the gas filter is supplied dismantled inside the boiler, for an
easier and safer transport.
It must be assembled once the boiler is in the plant.
The minimum gas pressure gauge is connected to the gas filter inlet.
In order to rotate the motor-fan group and take off the burner, you have to
remove first the gas filter and then proceed according to the instructions
indicated on the corresponding paragraph.
(1) Burner of fire resisting alloy mesh
(2) Ionization electrode (checking the flame
presence)
(3) Ignition electrode
(4) Pilot flame
(5) Venturi for the air-gas mix
(6) Double gas shut-off valve
(7) Gas inlet (boiler gas connection to the
installation)
(8) Fan for the air-gas mix
(9) Variable speed motor fan
(10) Air inlet
(11) Flange of the group motor-fan, to be coupled
to the flange of the boiler heat exchanger
(12) Ignition-ionization kit
(13) Pressure connection for the gas valve (just
models HT 250 and higher)
(15) Air filter (just models HT 250 and higher)

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8.1 Assembly of gas connection –air/gas inlet
The ADI HT boiler includes an air-gas premix system of modulating combustion, composed of:
1
B
8-9
2
66b 6a 7
15
Pa
5
13 Pg
10
V. Venturi operating as an air-gas mixer, ensuring combustion with a constant proportion of air/gas to the
premix burner, throughout its power modulation range.
The venturi produces a depression and drives the gas (G) towards the gas valve outlet (VV).
It operates as an additional safety: if there is no air inlet, there will be no gas admission.
VV. The gas shut-off valve regulates the gas outlet pressure according to the pressure value in the venturi.
Note: (13) in models HT 250 and higher: a coupling pipe between the gas shut-off valve and the venturi
measures the pressure drop before the mix. For lower models there is no pipe, the connection between the gas
shut-off valve and the venturi is internal.
M. The power modulation is realized by varying the fan speed, which also produces a variation of the
air-gas mix flow entering into the burner (B).
Pg. Minimum inlet pressure switch: adjusted at 15 mbar.
In Models ADI HT 105 to 200: these pieces form one only
global group: burner, burner-holder plate, motor-fan, venturi and
gas shut-off valve.

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Exploded view of the assembly burner –fan –gas valve for models HT 250 and higher:
Motor-fan rotating backward or
forward depending on the model.

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8.2 Air inlet filter
The air inlet to the venturi is protected by a filter retaining the dust that is
usually in the atmosphere.
Attention: it is important to avoid excessively dusty or dirty environments
(for ex. in case of building work in the same room or in places next to the
ventilation ducts of the boiler room) or environments with aggressive steams
(evacuation or air outlet of industrial laundries...).
See an example of the filter in the attached photo.
Just included in models HT 250 and higher.
8.2.1 Optional air filter for ADI little size
Optional air filter for ADI HT 130 to 200:
General view not assembled to boiler View assembled to the boiler (from above)
View of the lower part of the filter once assembled to the boiler
Optional air filter for ADI HT 105:

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9. BURNER
The boiler includes an air-gas premix burner of innovative design and material:
Fire resisting alloy mesh.
Homogeneous and stable combustion in case of any change in the power demand.
High mechanic resistance and high resistance to high temperatures.
Very low thermal inertia fast cooling (for an easier maintenance).
Fast answer to the changes of the power demand.
Thanks to its structure and design, noise produced by the combustion is very low and without resonance.
The cylindrical shape of the burner allows the flame to be homogeneously distributed. It is vertically introduced in
the boiler.
The boiler incorporates an ionization flame control. The minimum ionization value must always be superior to 5
microamperes.
9.1 Ignition and ionization kit
The ignition is electronic by means of
an electric transformer that produces
a train of sparks on the ignition
electrode (3), with the special feature
that the sparks fly from the electrode
to the mass included in this electrode,
and not on the burner.
The safety of flame presence is realized
by means of an ionization electrode (2).
The minimum ionization value must be
always higher than 5 microamperes.
Flame may be checked through the
glass spy (4).
(16) Electrodes holder plate
(17) Gasket for the set
ADI HT
Inclination
(X)
ELECTRODE/PROBE
Length (mm)
105 –275
9º
340
325 –475
5.5º
550 –950
7º
380
17
16
3
4
2
.
.
X

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10. CONTROL PANEL - SIEMENS
The boiler control panel is placed in the upper part of the boiler front.
ITEM
CONCEPT
1
RESET
Button for boiler reset when pressing > 0,5 s.
2
D.H.W. on/off
3
7471z49/0109
Select heating circuit mode. Change the operation mode:
Automatic mode: Circuit works according to the time program
Continuous operation according to Comfort setpoint
Continuous operation according to Reduced setpoint
Standby: circuit is disconnected, Frost Protection function activated
4
7471z54/0109
Available information is displayed by pressing the Info button
5
7471z51/0109
Turn the setting knob to select parameters.
For heating circuits, turn the setting knob to increase or decrease the Comfort
setpoint
7
4
7
1
4
7
e
/
0
2
0
9
Selection of heating operation mode
Display of information
Confirmation of setting
Chimney sweep function
safety limit thermostat test
Quitting the setting
Manual Operation
RESET
Selection of DHW heating mode
(A)
(B)
(A) Boiler on/off switch (B) Display: readings, messages, errors...