Viessmann VITODENS 200-W Service Instructions Manual page 20

Commissioning, inspection, maintenance
Further details regarding the individual steps
1. Switch OFF the main power supply
and the ON/OFF switch at the control
unit.
2. Close the gas shut-off valve and safe-
guard against reopening.
3. Pivot control unit A forward.
4. Remove cover panel B.
5. Pull cables from fan motor C, gas
train D, ignition unit E, earth tab
F and ionisation electrode G.
20
(cont.)
6. Release gas supply pipe H fitting.
7. Undo six screws K and remove the
burner.
8. Check burner gasket L for damage.
Generally replace the burner gasket
every 2 years.