Checking The Burner Flue Gas Flapper; Checking The Balanced Flue System Tightness (Annular Gap Check); Remove Burner Assembly - Viessmann VITODENS 222-F Service Instructions Manual

Service

Checking the Balanced Flue System Tightness (Annular Gap Check)

A Combustion air measuring port

Remove Burner Assembly

20
Vitodens 222-F B2TA 19 and 35 Service
Viessmann strongly recommends that the heating
contractor perform a simplified leak test during boiler
start-up. For this purpose it is sufficient to measure
the CO concentration of the combustion air in the
2
coaxial gap of the air intake pipe. The vent pipe is
considered sufficiently leak-proof if a CO
in the combustion air no higher than 0.2% or an O
concentration no lower than 20.6% is measured.
If higher CO values or lower O
2
check venting system thoroughly.
Note: The vent pipe adaptor comes with two
measurement ports, one for combustion air-intake
measurement and one for flue gas measurement.
1. Switch OFF the main power supply and the ON/OFF
switch 8 at the control unit.
2. Close the gas shut-off valve and safeguard against
reopening.
3. Remove front upper panel, see page 11.
4. Flip down control console, see page 11.
5. Remove boiler inner cover.
6. Pull electrical cables from fan motor A, gas valve B,
ionization electrode C, ignition unit D and ground
wire E.
7. Release gas supply pipe fitting F.
8. Remove four torx screws G.
9. Remove burner assembly.
CAUTION
To avoid damage to the burner, do not lay burner on its
cylindrical burner tube or touch the burner tube mesh.
Failure to heed this caution may cause damage to the
burner tube, which may lead to improper operation.
concentration
2
2
values are measured,
2