After having a problem with out Vaillant Vsmart controller our plumber installed this system.To say it’s next to useless is an understatement in comparison to the Vaillant.This may perhaps not be entirely the controllers fault it does control on and off but it definitely doesn’t do anything like our old controller this modulated the heating system so the house stayed at a constant temperature. Now you would have thought that with the brain power that Nest have behind them they could have had the controller also modulate the boiler to keep the house a constant temperature like the previous Vaillant model did.
