VAILLANT ECOTEC PLUS VUW 824 831 837 & PRO 24 28 FLOW SENSOR 178988 GENUINE PART

““FULLY REFURBISHED AND TESTED BY OUR ENGINEERS AND COME WITH 12 MONTH WARRANTY”” ✅ What this part actually is Flow sensor / turbine (aqua sensor) Detects hot water demand (tap opening) Sends signal to PCB to fire boiler 👉 If faulty, boiler won’t detect flow properly ✅ Confirmed compatible boiler models 🔥 Vaillant ecoTEC Plus (major range) ecoTEC Plus 824 (all variants 246/3-5, 246/5-5 etc.) ecoTEC Plus 825 ecoTEC Plus 831 (all R1–R5 variants) ecoTEC Plus 832 / 835 / 837 / 838 ecoTEC Plus 937 / 938 (VUI storage combis) 👉 Covers most generations of ecoTEC Plus 🔥 Vaillant ecoTEC Pro ecoTEC Pro 24 (all variants) ecoTEC Pro 26 ecoTEC Pro 28 ecoTEC Pro 30 👉 Includes older and newer revisions 🔥 Vaillant ecoTEC Exclusive ecoTEC Exclusive 832 ecoTEC Exclusive 838 🔥 Other ecoTEC variants VUW (combi) models VUI (storage combi) models Some regional condensing variants (Guernsey/Jersey models) 🧠 Key takeaway 178988 = very common Vaillant DHW flow sensor Used mainly in: ecoTEC Plus ecoTEC Pro ecoTEC Exclusive Covers dozens of models (especially combis) 👉 If your boiler is ecoTEC combi → high chance this is correct ⚠️ Important (very common confusion) This is often mixed up with: NTC sensors (temperature probes) ❌ PRVs (178985 / 178988 confusion) ❌ 👉 This one is specifically: ✔️ Flow detection (water movement) NOT temperature or pressure 🔧 Common fault symptoms No hot water when tap opens Boiler doesn’t fire on DHW Intermittent hot water Low flow detection / error codes 👍 Practical advice Before replacing: Check filter + plate heat exchanger (blockages mimic sensor faults) Check wiring to PCB 👉 These sensors do fail, but are often misdiagnosed