The 200-W has a large colour touchscreen. Plus raises the set temperature, minus lowers it.
- Open the heating or continuous-operation screen so the temperature is showing. With weather compensation this is often room temperature; in continuous operation it is the flow.
- Tap minus to lower it, or plus to raise it.
- Stop around 55°C flow if the house still warms. The factory standard flow is 60°C. If a room thermostat is in charge, set that as well.
Look up your exact model on Boiler Manuals if the fascia does not match. Then return to the Viessmann flow-temperature page or the Boiler Optimiser.