The Vaillant VR33 OpenTherm Module (part number
0020017895) is
an interface board that allows Vaillant boilers to communicate with third-party, modulating OpenTherm thermostats (such as Nest Heat Link, Tado, or Honeywell EvoHome)
- Modulation: Enables the boiler to continuously adjust its heat output to match real-time demand rather than simply switching completely on or off. Modulation allows for the boiler to activate at a much lower level if a room only needs a small top up in temperature ultimately saving gas
- Energy Efficiency: Prevents short-cycling (frequent turning on and off) and keeps home temperatures steady
- Fine control: Allows systems like Honeywell evohome or TADO to communicate and control the boiler.
- Increased comfort: Combining the fine per room control of systems like Honeywell Evohome and the modulation of the boiler increases the comfort levels throughout the home by only sending the required amount of heat to each room
The VR33 module is designed to fit inside the control/electronics box of several Vaillant boiler ranges, including:
Has been running flawlessly in my Vaillant ecoTEC plus boiler and connecting to a Honeywell Evohome system.