Vaillant Diverter Valve Repair Kit Cartridge 0020020015 178978 0020132682 Keep your heating running smoothly with a  diverter valve repair kit. Designed for dependable performance, this replacement part helps restore efficient operation and reliable heating/hot water delivery where applicable. Part number(s): 0020020015. 178978, 0020132682. Suitable for selected Vaillant ecoTec Plus, ecoTec Pro models (where specified). Why buy this part: ✔ Genuine, high-quality replacement ✔ Helps maintain efficient system performance ✔ Ideal for boiler repairs, servicing & maintenance ⚠️ We recommend that all parts are fitted by a fully qualified Gas Safe certified technician.