Vokèra OpenTherm 711 with external sensor connected
Setup guide to using the OpenTherm Control with an external weather compensation sensor fitted. If
you are unsure if an external sensor is fitted check the receiver unit. If the amber LED is lit there is an
external sensor fitted, so continue with this guide. If there is not solid amber LED use the other guide.
A flashing amber LED indicates loss of signal between room unit and receiver (check the battery in the
room unit).
When the OpenTherm control is installed it overrides the controls on the boiler fascia. For example the
OT Control will override the heating and hot water temperature settings on the boiler fascia. So your
OT controller is now the means by which you control your heating system and boiler. It also overrides
any other room thermostat or time control previously fitted to the system which may still be connected.
When the OpenTherm Control is connected to your boiler with an external weather compensation
sensor fitted, the room unit operates and displays differently than when no sensor is fitted.
With a weather compensation sensor fitted the room unit will have been programmed by the engineer
with a ‘heating curve’ set to give you an internal comfort level of 20°C when the weather outside is at
the lowest anticipated temperature for your part of the country.
In use if you find your heating too hot or cold, adjustment is possible to a maximum of 5°C above or
below the default temperature of 20°C.
With a weather compensation sensor fitted the heating gradient to the left of the display shows a pair
of bars.
Note for engineers: The heating curve must be set up on the room unit. Do not set a heating curve on
the boiler by following the instructions in the boiler manual as the OpenTherm control overrides the
boiler settings. The curve is set on the boiler only when an external sensor is fitted without an
OpenTherm.
VOKERA
