Vaillant Diverter Valve 178978

Vaillant Diverter Valve 178978 The Vaillant Diverter Valve (Part No: 178978) is a critical hydraulic component engineered for the first-generation ecoTEC range. This valve is responsible for switching the flow of primary heated water between the central heating circuit and the domestic hot water plate heat exchanger. It ensures that when a hot water demand is detected, the heating circuit is temporarily isolated to provide maximum thermal energy to the taps. Reliable Actuation: Designed to work in perfect synchronization with the diverter motor to ensure smooth and immediate switching between modes. Preventing Heat Bleed: Features precision-molded internal seals that prevent hot water from leaking into the radiators while the boiler is providing domestic hot water. High-Quality Construction: Manufactured using durable, heat-resistant composite materials to withstand the high pressures and temperatures of a condensing boiler system. Direct Replacement: This is the genuine OEM part required for addressing common "crossover" faults or blocked domestic hot water delivery in early ecoTEC plus and pro models. Compatible Models: VAILLANT ecoTEC plus 824 (2005-2005) VAILLANT ecoTEC plus 824 (2005-2010) VAILLANT ecoTEC plus 831 (2005-2005) VAILLANT ecoTEC plus 831 (2005-2010) VAILLANT ecoTEC plus 837 (2006-2010) VAILLANT ecoTEC plus 937 (2006-2010) VAILLANT ecoTEC pro 24 (2006-2010) VAILLANT ecoTEC pro 28 (2005-2010) VAILLANT VUI 376/3-5 (2006-2010) VAILLANT VUW 246/3-3 R1 (2006-2010) VAILLANT VUW 246/3-5 (2005-2005) VAILLANT VUW 246/3-5 R1 (2005-2010) VAILLANT VUW 286/3-3 (2005-2005) VAILLANT VUW 286/3-3 R1 (2005-2010) VAILLANT VUW 316/3-5 (2005-2005) VAILLANT VUW 316/3-5 R1 (2005-2010) VAILLANT VUW 376/3-5 R1 (2006-2010) Vaillant Ecotec Plus 824 VUW 246/3-5 2005-2012 — 47-044-31 Vaillant Ecotec Plus 831 VUW 316/3-5 2005-2013 — 47-044-32 Vaillant Ecotec Plus 937 VUI 376/3-5 2006-2012 — 47-044-39 Vaillant Ecotec Pro 24 VUW 246/3-3 R1 2006-2008 — 47-044-36 R1 Vaillant Ecotec Pro 24 VUW 246/3-3 R2 2008-2012 — 47-044-36 R2 Vaillant Ecotec Pro 28 VUW 286/3-3 R1 2005-2008 — 47-044-30 R1 Vaillant Ecotec Pro 28 VUW 286/3-3 R2 2008-2012 — 47-044-30 R2 Vaillant A00312-03