PART IV: MAINTENANCE
30
6.2 Replacing the spring in the gas valve group
6.3 Removing the combustion head
z
Remove the cover
C
.
z
remove the electrodes cables;
z
unscrew the 3 screws
V
which hold in position the gas manifold
G
and pull out the complete group as shown in the picture below.
z
Clean the combustion head by a compressed air blow or, in case of scale, scrape it off by a scratchbrush.
Note:
to replace the combustion head reverse the procedure described above having care to place correctly the O ring (
OR
) between
burner and gas manifold.
To replace the spring in the gas valve group,proceed as follows:
1
Carefully twist the protection cap 1 and the O-ring 2.
2
remove the “set value” spring 3 from housing 4.
3
Replace spring 3.
4
Carefully insert the new “set value” spring. Pay attention to mount properly.
First insert the spring part with smaller diameter in the housing.
5
Place O-ring 2 in protective cap 1. Screw in the protective cap with the O-
ring in it.
6
Stick the adhesive label for spring identification on the type plate.
Fig. 14
Key
VRT
Head adjusting screw
AR
Threaded rod
V
Fixing screw
G
Gas manifold
OR
”O” ring
C
Cover
1
3
SKP Siemens actuator
V
C
G
AR
OR
VRT
C
AR
G
