Instruction manual GWV 69

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12 Service program

12.1 Introduction

The service program is used by the installation
engineer or service and maintenance engineer for:
•Setting the hysteresis;
•Displaying the error history;
•Displaying the appliance history;
•Displaying the appliance selection;
•Switching the pump on or off;
•Setting the service interval;
•Setting the display contrast;
•Setting the display backlight switching period;
•Setting the display scroll speed;
•Setting the stage difference for the appliance;
•Setting the pump running-on time.
These submenus are briefly described in the following
paragraphs. If you are not familiar in general with how
to use the displays and menus, first read the
relevant (7 "The control panel") chapter.
Note
The notation convention for the service menu is
identical to that of the main menu (11.2"Notational
convention for menu-related instructions"). The
difference is that you use to call up the service
program, instead of , which calls up the main menu.

12.2 Setting the hysteresis

If the preset temperature (SET POINT) is higher than
the current water temperature, the appliance might not
immediately start the heating cycle (2.3 "The
appliance's heating cycle"). This is caused by the built-
in safety margin. To prevent excessively frequent
switching on and off, there is a heating margin. This
margin is called the hysteresis. The hysteresis can be
set DOWN (negative hysteresis). The hysteresis can
be adjusted between 2°C and 7°C.
Set the hysteresis DOWN as follows:
•:
HYSTERESIS DOWN
The figure shows an example.

12.3 Displaying the error history

Display the error history as follows:
•:
HISTORY OF ERRORS
The controller will display an overview of "Blocking
errors" and "Lock out errors". In both cases, the
electronic controller reserves 15 lines for the last 15
error messages. If there are fewer than 15 error
messages, three points (...) are displayed. The display
first shows the "Blocking errors". When is
pressed, the "Lock out errors" are displayed.
The figure shows an example of "Blocking errors". The
HISTORY OF ERRORS
text is followed by
(B)
.
The figure shows an example of "Lock out errors". The
HISTORY OF ERRORS
text is now followed by
(L)
.
Note
For an overview of all errors and the possible
causes, please refer to the relevant
chapter(13 "Troubleshooting").

12.4 Displaying the appliance history

The appliance history submenu is used to display the
burning hours, the number of ignitions, the number of
flame errors and the number of ignition errors.
Call up the menu for displaying the appliance history
as follows:
•:
APPLIANCE HISTORY
The figure shows an example.
SERVICE MENU
»HYSTERESIS
^ HISTORY OF ERRORS
È APPLIANCE HISTORY
SELECT APPLIANCE
PUMP RELAY
SERVICE INTERVAL
DISPLAY CONTRAST
BACKLIGHT TIME
SCROLL SPEED
STAGE DIFFERENCE
PUMP POST PURGE
HYSTERESIS DOWN »4ÉC
HISTORY OF ERRORS(B)
S04 SENSOR ERROR
F06 IONISATION
È CO2 50 HZ ERROR
HISTORY OF ERRORS(L)
F02 FAN
F07 FLAME ERROR
È ...