Pre-Service Check List - Worcester benchmark ZWB 7-25 R 25 HE Design, Installation And Servicing Instructions

Maintenance
8.1

Pre-Service Check List

1 Call up the last fault stored by the
Bosch Heatronic, Service Function .0,
(see page 35).
2 Check ionisation current, Service
Function 3.3, (see page 35).
3 Perform visual check of air/flue duct.
Visual check of diaphragm for soiling
and splits (see page 37).
4 Check gas supply pressure
(see page 30).
5 Test combustion air/flue gas
(see page 32).
6 Check CO setting for min./
2
max. (gas/air ratio)
(see page 30).
7 Check gas and water systems for
leaks (see page 16).
8 On combi models, check hot water
outlet temperature (see page 35).
9 Check heat exchanger
(see page 35).
10 Check burner (see page 36).
11 Clean condensation trap
(see page 37).
12 Check charge pressure of
expansion vessel matches
static head of heating system.
13 Check central heating system
pressure.
14 Check electrical wiring for damage.
15 Check heating programmer settings.
16 Check appliances that are part of
the heating system
Table 16
34
Date
mbar
min. %
max. %
mbar
mbar
mbar
6 720 611 441 GB (03.11)