Grant 50/70 - Page 41

41
Grant Vortex Indoor/Utility, System and Boiler House Oil Boilers
9 - BOILER SERVICING
Fig. 30
Combustion
head
Combustion head
fixing screw
Electrode clamp
screw
Electrode
leads
Nozzle
holder
Diffuser clamp
screw
Burner
flange
Fig. 31
Fig. 32
0
Screw
Slotted ring
Screw Combustion
head
Combustion
head fixing
screw
A
B
Electrode clamp screw
5.75
0
-0.2
3
+0.5
0
Diffuser clamp screw
4.0
+0.5
7.5
+0.7
- 0.5
_
B
A
Diffuser disc
155/200 or 200/240 models - See Section 13.2 and Fig. 30
1 Combustion head - Loosen the two screws
securing the combustion head (NOT the screws in
the slotted ring, Fig. 32) and withdraw the head.
Clean and refit the combustion head.
2 Inspect the ignition electrodes - Remove the
combustion head.
Loosen the electrode clamp screw, disconnect the
leads and withdraw the electrode assembly. Wipe
clean and check for any cracks in the ceramic
insulation. Replace if necessary.
3 Check the electrode and diffuser settings - Fig. 31
To adjust the diffuser disc: Loosen the diffuser clamp
screw and slide the disc along the nozzle holder to
achieve the gap 'A' in Fig. 31, tighten the screw.
To adjust the electrodes: Loosen the electrode
clamp screw and move the electrode unit to achieve
the gap 'B' in Fig. 31, tighten the screw.
4 The combustion head position is adjustable on the
155/200 and 200/240 burners. Check that it is fully
closed (position 0), or the 4th line if the 200/240
has been set to maximum output (70 kW).
To adjust the head setting, refer to Fig. 32 and
proceed as follows: Loosen the two screws in the
slotted ring - NOT the two fixing screws, and turn
the blast tube until '0' lines up with the edge of the
slotted ring. Tighten the two screws.
All models
1 Photocell - The photocell is a push-fit in the burner
body. Carefully pull out the photocell to clean.
2 Burner fan - With the air intake grille or spigot
removed, remove the screws securing the fan
housing cover (R/H side of burner) and remove the
cover. Inspect the fan and housing and clean as
necessary. Replace the cover.
3 Pump filter - With the burner cover removed,
remove the four screws securing the pump end
cover. Remove the filter and wash in kerosene.
Replace the filter and end cover, ensure the 'O' ring
is in position. Check for the presence of sludge or
water.
Re-assemble in reverse order.
To ensure safe and efficient operation of the boiler
it is important that re-commissioning is carried out,
especially combustion checks (CO
2
level, flue gas
temperature and smoke number) after the boiler
has been serviced.
Refer to the Commissioning instructions starting on
page 35.