Diverter Valves

The diverter valve is an essential component found exclusively in combi boilers.
It controls the flow of heated water, directing it either to your central heating system or to your domestic hot water taps on demand. When you open a hot tap, the valve switches the flow to your water supply; when the tap is turned off, it redirects the heated water back to your radiators. This seamless switching is what allows a combi boiler to deliver instant hot water without the need for a separate storage cylinder.
A worn or faulty diverter valve can cause a range of common issues, including lukewarm radiators even when the hot water works fine, hot water only working when the heating is on, or a complete failure to divert to either circuit.