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 hard-
ness and pH value on page 16
and 17.

Fully opening the flue outlet damper and locking it open

The damper must be in the horizontal
position.

Starting the heating system

Operating instructions – con-
trol unit, burner and neutralis-
ing system, service
instructions – control unit and
burner manufacturer's docu-
mentation
1. Check the heating system pres-
sure.
Permissible boiler operating pres-
sure: 4 bar
2. Check that the boiler room ventila-
tion aperture is open.
3. Check the gas supply pressure.
Commissioning, inspection, maintenance
Control unit installation and
service instructions
!
Please note
Unsuitable water qualities can
result in damage to the boiler
body and the heating system.
Observe the "Water quality
requirements" on page 30.
Note
For handling the damper, see "Mini-
mising pulsation noises", page 8.
4. Check that the cleaning aperture
on the flue outlet is closed.
5. Open the gas supply line shut-off
valves.
6. Switch ON the main isolator, the
switch for the heating circuit pump
and the burner control switch, in
that order.
Burner manufacturer's oper-
ating instructions
7