I have combi boiler in Spain which often switches of in mid stream when hot water heating is on demand and will not stay on even when reset. The gas regulator and diverter valve have been changed but no success. The boiler is a Vaillant VC/VCM 182-282 and is about 12 years old. The hot water heating often works better in winter when the central heating is on. Pressure and temperature are set OK. Has anyone any ideas. Several attempts with local servicing companies have not worked.
