Viessmann VITOLIGNO 300-H Series Operating Instructions Manual page 53

Cleaning the light barriers
Danger
Hot surfaces and fire from apertures can result
in severe burns.
Doors, covers and apertures fastened shut
■
with screws must not be opened during heat-
ing operation.
■ Switch OFF the boiler before maintenance and
cleaning work and allow the boiler to cool
down.
Do not touch hot surfaces on or in the boiler,
■
burner, flue system or pipework.
■ Wear suitable personal protective equipment.
Vitoligno 300-H, 50 to 60 kW
1.
Fig. 41
1. Switch OFF the boiler before maintenance and
cleaning work and allow the boiler to cool down.
Unscrew the cover.
2. Undo the top of the sight glass and clean the sight
glass.
2.
3. Refit the top of the sight glass and the cover.
4. Repeat on the opposite side of the boiler.
5. Switch the boiler ON again.
Maintenance
53