Installation & Servicing instructions ATAG iC-Range
38
12 Boiler controls
Before the electrical power is switched on, it helps to know the operation of the boiler in advance. On this
page the controls are described in short. The next page describes the button functions and the symbols on
the screen.
The boiler is equipped with self-managing control system. This control system takes over a large part of the
manual settings, which simplifies the start-up of the installation considerably.
After filling the installation and switching on the electrical power supply a short start-up program is activated.
This shows all digits, boiler type and software version and the automatic air purge program is activated. The
automatic air purge program lasts for approx. 7 minutes and stops automatically. The boiler fires up for DHW
to bring the primary heat exchanger to the set comfort temperature. Then the boiler will switch on for the
enabled program (CH or DHW) (See chapter 11 ‘Filling and bleeding boiler and installation’).
DHW controls (combination boilers)
If a hot water tap is opened the flow sensor measures (F1) the amount drawn off. Depending on the
desired DHW temperature and volume the controls will calculate an output. This realises the desired water
temperature in an efficient way. The hot water sensor (T3) will adjust any minor deviations caused by
temperature fluctuations so that even under these circumstances the desired temperature is constant.
CH controls
With a demand from the heating controls after DHW demand, the boiler
activates its 1 minute delay period. This is to prevent the heat exchanger
from losing its heat too quickly in the event of a hot water demand. Then
the pump starts and after 30 seconds the gradient control becomes
active. The starting point of the gradient control is the currently existing
flow temperature. A Delta-T control (25K) ensures a stable control
according to heat request.
If the flow temperature is below the T-set value of 20°C the boiler will
immediately start.
If during a demand from the heating the burner switches off, because the
desired flow temperature is exceeded, there will be an anti-cycle time in
operation for 5 minutes. This means that the burner switches on again
after 5 minutes if there is still a demand from the heating.
The ATAG iC is equipped with boiler sensors of 10kOhm. The resistance
value and corresponding temperature are shown in the accompanying
table.
Resistance table
table 12.a
NTC1k (25°C)
NTC10k (25°C)
Temperature Resistance Temperature
Resistance
[°C]
[Ohm]
[°C]
[Ohm]
-10
4.574
-10
55.047
-9
4.358
0
32.555
-8
4.152
10
19.873
-7
3.958
12
18.069
-6
3.774
14
16.447
-5
3.600
16
14.988
-4
3.435
18
13.674
Resistance table sensors ATAG iC-, iS- and iR-series
Outside sensor T4
Flow sensor T1
Return sensor T2
DHW sensor T3
4
3.435
18
13.674
-3
3.279
20
12.488
-2
3.131
22
11.417
-1
2.990
24
10.449
0
2.857
26
9.573
1
2.730
28
8.779
2
2.610
30
8.059
3
2.496
32
7.406
4
2.387
34
6.811
5
2.284
36
6.271
6
2.186
38
5.779
7
2.093
40
5.330
8
2.004
42
4.921
9
1.920
44
4.547
10
1.840
46
4.205
11
1.763
48
3.892
63
8
3 89
12
1.690
50
3.605
13
1.621
52
3.343
14
1.555
54
3.102
15
1.492
56
2.880
16
1.433
58
2.677
17
1.375
60
2.490
18
1.320
62
2.318
19
1.268
64
2.159
20
1.218
66
2.013
21
1.170
68
1.878
22
1.125
70
1.753
23
1.081
72
1.638
24
1.040
74
1.531
25
1.000
76
1.433
26
962
78
1.341
27
926
80
1.256
28
892
82
1.178
29
858
84
1.105
30
827
86
1.037
35
687
88
974
40
575
90
915
