Further Details Regarding The Individual Steps; Checking The High Limit Safety Cut-Out Setting; Filling The Heating System With Water And Venting The System; Fully Opening The Flue Outlet Damper And Locking It Open - Viessmann VITOCROSSAL 300 Service Instructions Manual

Further details regarding the individual steps

Checking the high limit safety cut-out setting

The high limit safety cut-out must not be
set higher than 110 °C; if required, set it
to a maximum of 110 °C.

Filling the heating system with water and venting the system

Record the fill volume, water hardness
and pH value on page 14.
Permissible boiler operating pressure: 4
bar.

Fully opening the flue outlet damper and locking it open

The damper must be in the horizontal
position.

Starting the system

Operating instructions – control
unit, burner and neutralising sys-
tem, service instructions – control
unit and burner manufacturer's
documentation
1. Check the heating system pressure.
Permissible boiler operating pres-
sure: 4 bar
2. Check that the installation room vent
is open.
Commissioning, inspection, maintenance
Control unit installation and serv-
ice instructions
!
Please note
Unsuitable water qualities can
result in damage to the boiler
body and the heating system.
According to VDI Directive 2035,
the heating system must be filled
and operated with water with a
sum of alkaline earths not
exceeding 0.02 mol/m
hardness 0.11 °dH).
Observe the "Water quality
requirements" on page 25.
Note
For handling the damper, see "Minimis-
ing pulsation noise", page 8.
3. Check the gas supply pressure.
4. Check that the cleaning aperture on
the flue outlet is closed.
5. Open the gas line shut-off valves.
3 (overall
7