Boiler Repair in Swanley – No Hot Water

A homeowner in Swanley contacted us on a Monday morning reporting that their heating was working fine but they had no hot water at all. The boiler — a Worcester Bosch Greenstar 30i — was firing normally and all radiators were heating up, but nothing was coming through to the taps or shower. This is a classic symptom of a diverter valve failure. In a combi boiler, the diverter valve is responsible for switching the flow of hot water between the central heating circuit and the domestic hot water circuit. When it fails — either getting stuck in one position or becoming sluggish — the boiler prioritises heating and effectively ignores calls for hot water.

Our Gas Safe engineer arrived that afternoon and confirmed the diagnosis within minutes. A quick temperature check at the hot water outlet confirmed no heat was being diverted from the heating circuit, and a visual inspection showed the diverter valve cartridge was worn and had failed in the heating-priority position. We carried a replacement diverter valve cartridge for the Worcester Bosch Greenstar series on the van. The repair was completed within 45 minutes — old cartridge removed, new one fitted, system re-pressurised and tested. Hot water was restored immediately at full temperature. We also carried out a quick check on the rest of the boiler while on site and confirmed everything else was in good condition.