Checking The Balanced Flue System For Tightness (Annular Gap Check); Draining The Boiler - Viessmann Vitopend 100-W Installation And Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps
Checking the balanced flue system for tightness (annular gap
check)
A
A Combustion air test point (ventila-
tion air)

Draining the boiler

!
Please note
Risk of scalding
Only drain the boiler once the
boiler water temperature has
dropped below 40 °C.
To check the current boiler water
temperature, see page 69.
52
(cont.)
The flue pipe is deemed to be suffi-
ciently gas-tight if the CO
tion in the combustion air is no higher
than 0.2% or the O
least 20.6%.
If actual CO values are higher or O
2
values are lower, then pressure test the
flue pipe with a static pressure of
200 Pa.
1. Turn off the ON/OFF switch on the
control unit and the power supply.
concentra-
2
concentration is at
2
2
A