Vaillant ecoTEC PRO 28 leaking diverter valve repair

Vaillant ecoTEC PRO 28 leaking diverter valve repair – Thurgoland, Sheffield, S35.

This was just supposed to be a standard service on a boiler which I serviced a couple of years prior. When I was checking the boiler over I noticed that the diverter valve was leaking slightly when it was moving between domestic hot water and central heating mode.