Vitodens 100-W WB1B control problems via Tado

I have a Viessman Vitodens 100-W WB1B which the heating is controlled via a Tado Extension kit (via opentherm) and smart thermostat.

When the hot water is called it supplies the cylinder for a set time or until the temp is reached but it doesn't always go back to supply the heating even though Tado is calling for heat. It sits in limbo with a temp display but no HW or Heating symbol or power display.

Also periodically it resets the boiler and all the symbols briefly display until the temp and heating and power show up and it functions fine for a while.

I have spoken with Viessman TS and they say its a Tado control issue

Answers