Viessmann Vitodens 100-W B1HA 26Vitodens 100-W B1HA 35Vitodens 100-W B1KA 35 Installation And Service Instructions Manual page 60

Troubleshooting
Boiler Connection
The setting range is dependant on the temperature control
display (°C/°F).
When the control is set to °F the display will read 'off'.
and the display will read 41*
Tap up with /
increments of 1.
When the control is set to °C the display will read 'off'.
and the display will read 5*
Tap up with /
increments of 1.
60
(continued)
Outside temperature
.
1
Tap / for
.
2
Tap / for
Vitodens 100-W, B1HA series & B1KA Combi Installation/Service
Heating curve for weather-compensated control
In weather-compensated mode, the boiler water
temperature is regulated subject to the outside
temperature. Perameter default setting is 20 (or 68
if display is converted to °F).
Set heating curve
1. Tap / .
The set parameter flashes and r will be displayed.
2. Use / to select the parameter.
3. OK to confirm.
Note: When adjusting this setting, bear in mind that
your heating system requires some time to heat
the home to the required temperature.
Frost protection function
The frost protection function requires an outside
temperature sensor to be connected. The frost protection
function becomes active at outside temperatures of
<41°F (<5°C). The burner starts and the boiler water
temperature is held at 68°F (20°C).