Viessmann VITOLIGNO 250-S Operating Instructions Manual page 15

Heat-up preparations
4. Check that the heating system has been vented.
5. Ensure that all shut-off gate valves to the heating
flow and return are open.
6. Check that all doors and covers on the boiler are
closed.
7. Ensure that all ball valves for the return tempera-
ture raising facility are open.
Heat-up
Before heating up: Check that all required conditions
have been met. See chapter "Heat-up preparations"
from page 14.
Opening the hopper cover
Danger
Deflagration and poisonous flue gases can
cause serious injuries.
Never open the hopper cover in any operating
phase until the flue gas temperature has fallen
below 120 °C or 248 °F.
Danger
Poking around in the firebed leads to oxygena-
tion, which can produce a flash.
Never poke around in the firebed.
B
A
Fig. 8
(cont.)
8. Ensure that power is supplied to the boiler.
!
Please note
Risk of damage to the pressure-jet oil/gas
burner (if installed) when operating the boiler
with logs.
Ensure that the pressure-jet oil/gas burner
has been extended prior to operation with
logs.
1. Initially open the hopper cover to lock
2. Turn mushroom handle
cover and fully open the cover.
Start-up/shutdown
.
A
to unlock the hopper
B
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