Bosch Heatronic Board Functions; Initialisation; Temperature Display; Indication Of Faults - Benchmark ZWB 7-29 CC1 Installation And Servicing

Bosch Heatronic board functions

2 Bosch Heatronic board func-
tions
2.1

Initialisation

When it is switched on, the appliance performs a self-
test which takes about 5 seconds. While the test is in
progress, the display shows the following sequence of
codes:
P1 -> P2 -> P3 -> P4 -> P5 -> P6
On completion of the test sequence the appliance is
ready for operation.
2.2

Temperature display

The display shows the current flow temperature in cen-
tral heating and hot water modes. The display range
extends from 00 ˚C to 99 ˚C.
If a service function requires the display of a tempera-
ture greater than 99 ˚C, the display alternates between
initially showing the first digit and then the remaining
two digits.
E.g.: display showing 1. followed by 69. indicates
169˚C.
For outside temperatures, the display shows a minus
sign followed by the negative temperature in alternation.
2.3

Indication of faults

Faults are indicated by a letter code. This helps to iden-
tify and eliminate the cause of the fault quickly and reli-
ably.
The fault codes displayed are grouped into four catego-
ries:
• Category 1:
The appliance is disabled until it has been switched
off and then on again.
• Category 2:
The appliance is disabled until the cause of the fault
has been eliminated.
• Category 3:
The appliance continues to operate with limited func-
tion.
• Category 4:
The appliance is disabled and locked (
until the cause of the fault has been eliminated and
the appliance unlocked.
Unlocking the appliance:
i
B Press and hold the
display shows – – .
6
flashes)
button until the
2.4

Special programme visualisation

The display shows for example 45
ous working at the minimum sanitary/heating
power)
The display shows alternatively the temperature
and . The function is memorised in the Service mode.
– –
• The appliance works continuously at the sanitary or
heating minimum power.
B Press the button
until the symbol
the display.
The button is lighted.
B Turn the temperature control
appears on the display.
After a short delay, the display shows 1 for minimum
output.
B Turn the temperature control
clockwise until the display shows 0 .
B Press the button
until the symbol [ ] appears on
the display.
The display shows the heating outlet temperature.
The display shows for example 55
(continuous working at the maximum power)
The display shows alternatively the temperature and
The function is memorised in the Service mode.
• The appliance works continuously at the maximum
power.
B Press the button
until the symbol
the display.
The button is lighted.
B Turn the temperature control
appears on the display.
After about 5 seconds the display will show 2 for the
maximum power.
B Turn the temperature control
clockwise until the display shows 0 .
B Press the button
until the symbol [ ] appears on
the display.
The display shows the heating outlet temperature.
Display shows 45 -II- 45 (trap filling programme)
The trap filling programme ensures that the condensa-
tion trap is filled after the appliance is first installed or if
it has been switched off for a long period.
The trap filling programme is activated if:
• the appliance is switched on at the master switch
• the burner has not been in operation for at least 48
hours
• the appliance is switched from summer to winter
mode.
45 (continu-
– –
appears on
– –
until function 2.0
completely anti-
– –
55
– –
.
– –
appears on
until function 2.0
completely anti-
7 181 465 346 GB (03.02)