What does the Vaillant ecoFIT pure F43 fault code mean?
The F43 fault code on the Vaillant ecoFIT pure indicates a malfunction with the diverter valve, which is responsible for directing hot water to either the heating system or the hot water supply. This issue can lead to inadequate heating or hot water supply, affecting the overall performance of the boiler.
Common Causes
- Blockage in the Diverter Valve: Debris or limescale buildup can obstruct the diverter valve’s movement, preventing it from functioning correctly.
- Electrical Fault: A failure in the electrical components or wiring connected to the diverter valve can cause it to malfunction, leading to the F43 error code.
Can I fix it myself? (DIY)
It is not advisable to attempt repairs on the diverter valve yourself, as this involves gas and electrical components that require a qualified Gas Safe Engineer. If you suspect a pressure issue, you can check the boiler pressure gauge and reset the boiler according to the manufacturer’s instructions, but for diverter valve issues, professional assistance is essential.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the diverter valve on a Vaillant ecoFIT pure is approximately £250 to £350. This includes the cost of the replacement part and labour, as diverter valves can be complex to access and replace, requiring professional expertise.