I have a Vaillant Aqua Plus (VUI 280-7) boiler that has an analog interface (pins 7-8-9) for flame modulation, so it expects a DC voltage range.
I would like to install a Honeywell Evohome system in my house that has an OpenTherm interface for flame modulation.
The boiler is still in a good shape, so no reason to replace it yet with a more modern one that has an OpenTherm interface, but instead it would be great if I could find an OpenTherm --> Analog converter that can be applied to my boiler.
Can anybody help me in this regards?
OpenTherm --> Analog Converter
Moderator: hvxl
Re: OpenTherm --> Analog Converter
I don't expect such a device is possible. In the Opentherm protocol, a thermostat tells the boiler how hard to heat by specifying a desired water temperature, rather than a straight percentage or something like that. Probably your analog interface just wants a voltage with a direct relationship of how high the flame should be.
In addition, an Opentherm thermostat needs a bunch of information from the boiler to determine the desired water temperature. The analog interface of your boiler doesn't provide that information.
In addition, an Opentherm thermostat needs a bunch of information from the boiler to determine the desired water temperature. The analog interface of your boiler doesn't provide that information.
Schelte