Diverter Valves on combination boilers send primary water either through the central heating circuit or to a heat exchanger to indirectly transfer heat to the domestic hot water. The diverter valve will not do central heating and hot water at the same time. Combination boilers always give priority to hot water so there is no middle position.
There are four main types of diversion method –
1- Pressure differential valves.
2- Electric motor valves.
3- Wax capsule diverter.
4- Twin pump diversion.
General faults are normally attributable to poor system water quality – the most common problems are –
1- The diaphragm deteriorates or splits.
2- There is debris on the valve seat thus water passes through a closed valve seat.
3- Pushrods seize or pass water.
4- Physical blockages.
5- Motor burns out.
6- Non return valves seize or pass water (twin pump diversion).
7- Dripping tap holds heating off (wax capsule diverter).