I had a boiler fitted February this year type valliant eco tec pro 28. The small white box on wall next to boiler keeps tripping therefore the boiler does not work for the radiators, yet I can still get hot water from the boiler, whats going on here with the boiler?
The small white box on the wall is the Controller. If this control unit is tripping then you have an electrical fault that needs to be investigated and corrected by an electrician. A fault in this box would definitely prevent hot water from traveling to your radiators. You are still getting hot water to your taps, showers etc because you have a combi boiler and this functionality is not controlled by the control unit.