Heat Interface Unit Function Test Menu; Central Heating Pump Test; Heat Meter (If Fitted); Component Resistance Characteristics - Bosch Worcester Greenstar HIU E Installation And Maintenance Instructions Manual

Fault finding and diagnostics
9.6.4

Heat Interface Unit function test menu

▶ Enter the Service menu and navigate through the menus and select
the Diagnosis menu.
▶ Navigate through the Diagnosis menu and select the Function test
menu.
▶ Navigate through the Function test menu and select the Heat
Interface Unit menu.
▶ Select the parameter and adjust to test the valve.
Heat Interface Unit
parameter Description
DHW Set DHW control valve position (%).
• 0%(closed - 100% (fully open)
CH Set CH control valve position (%).
• 0%(closed - 100% (fully open)
Table 41
9.7

Central heating pump test

To check the pump operation of the central heating pump
▶ Set the central heating rotary switch to the pump (
– Ensure the central heating rotary switch is returned to its original
position for normal central heating operation.
9.8

Heat meter (if fitted)

The integrator display an error message with the 3 letters "Err" and a
code. If several errors occur at the same time, the different codes are
shown sequentially.
The error is displayed in the first position of the display menu. It will still
be possible to select all the other display menus by pressing the
navigation button, refer to section 6.8.
If the navigation button is no longer pressed for a period of 3 minutes,
the error code automatically appear again in the first position of a display
menu. Display of an error automatically disappears when the error is no
longer present.
• Err. 1
– Flow higher that 1.2 x qs or defective hydraulic sensor.
• Err. 2
– Measured temperature outside the homologated range or
temperature sensor is defective.
Fig. 80 Error display
64
9.9

Component resistance characteristics

9.9.1

Flow/return temperature NTC sensors

Resistance ( Ω)
29529
18787
12257
8186
5586
3889
Table 42 Central heating/district sensors
9.9.2

DHW NTC wet sensor

Resistance ( Ω)
14772
11981
9786
8047
) position.
6653
5523
4608
3856
3243
2744
2322
1990
1704
1464
1262
1093
950
Table 43 DHW wet sensor
9.9.3

Outdoor weather compensation sensor

Resistance ( Ω)
2392
2088
1811
1
1562
1342
1149
948
842
781
642
528
436
Table 44 Outdoor weather compensation sensor
Temperature ( °C)
0
10
20
30
40
50
Temperature ( °C)
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Temperature ( °C)
-20
-16
-12
-8
-4
0
4
8
10
15
20
25
6 720 808 928 (2017/06)