Buderus 800 - 5.3.20 Replacing the gas valve assembly

Servicing 5
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
59
5.3.19 Checking the gas-burner assembly for correct
activation
 Set the mains switch to “0”.
 Remove a plug-in cable at the main gas valve and
connect a current-measuring device, at the same
point, with a measuring range of up to 1000 mA AC
(fig. 81, item 1).
 Set the mains switch to “I”.
 Unblock the 800 Series by pressing "reset" button,
and take current reading during start-up procedure.
 Carry out the same measuring procedure at the
ignition-gas valve (fig. 81, item 2).
 If the current reading at pos. 1 is approximately
210 mA and the reading at pos. 2 is about 450 mA,
the gas-valve activation system is in order.
 Set the mains switch to “0”.
 If the gas-valve assembly activation system is in or-
der, plug the cable in once more.
5.3.20 Replacing the gas valve assembly
 Disconnect the system from the power supply.
 Close the gas shutoff valve.
 Remove all plug-in cables from the gas valve assem-
bly. Note order of cable terminals.
 Loosen the screw-in adapter on the tube connector.
 Remove the valve assembly and replace with a new
unit; attaching it to the screw-in connection adapter.
 Connect all plug-in cables in the correct order.
With the system running, check for leaks at all joints
likely to have been affected by the fitting of replacement
parts.
fig. 81 Checking the gas valve assembly activation system
(HONEYWELL valve assembly shown as example)
1
2
fig. 82 Gas valve assembly replacement (HONEYWELL
valve assembly shown as example)
CAUTION!
Work on gas pipes and fittings must only be
carried out by a registered service provider.
NOTE
Carry out all initial start-up tasks as
indicated in the installation and servicing
instructions, and complete the
corresponding report form.