- Vaillant Error F76 Fault Code: Overheating on Primary Heat Exchanger.
This is a specific fault code that relates to the heat engine of the Vaillant Ecotec boiler becoming too hot. The boiler has a preset parameter at which it will deem excessive temperature as unsafe, once this is reached it will revert to error F76 as a failsafe. If the heat exchanger is blocked or one of a number of other hydraulic blockages are present this fault code will occur, and it can happen if the temperature sensor itself is defective. It can also occur if the boiler pump is weak or happens to fail completely in the middle of a firing cycle although this would more likely cause a different fault code. If this fault occurs then there is little the end user can do other than verify the correct water pressure. If this seems correct then a boiler repair engineer should be consulted as overheating can be an indication of a severe and potentially dangerous boiler breakdown.
- Vaillant Error F22 Fault Code: Insufficient water pressure
This fault code occurs when the digital pressure sensor is subject to insufficient pressure in the primary system water. It is generally a simple fix which can be undertaken by the end user by following these instructions. It is worth noting however that a faulty pressure sensor or blockage can cause this issue even if there is sufficient water in the system so care should be taken if refilling the boiler does not seem to reset the boiler. if the boiler also has an analogue pressure gauge then this should be consulted too to verify that the primary system does indeed not have enough water present.
- Vaillant Error F68 Fault Code: Unstable Flame Signal
This fault code is fairly generic and can indicate numerous faults with the heat exchanger and / or gas train of the boiler. Anything which can cause the boiler flame to be detected as unstable can lead to this fault code; the most common of which are incorrect gas meter pressure (fairly common), water in the heat exchanger due to a blocked condensation drain (very common), faulty air/gas flue system, incorrect air/gas ratio due to improper servicing or incorrect commissioning, or an issue relating to the ionisation system. All of these matters are within the realm of a Gas Safe engineer only and little diagnosis or rectification can be done by the end user here.
- Vaillant Error F28 Fault Code: Failure During Startup Ignition Unsuccessful
This common fault code is a somewhat generic one (Vaillant do love generic fault codes) which relates to the boiler unsuccessfully completing its ignition stage. Most commonly this is due to insufficient gas being present at the gas valve (for example a prepayment gas meter being out of credit or mains gas turned off by National Grid due to maintenance works), although it can occur when the gas valve or ionisation probe are faulty. If this fault occurs in your home then check that you have gas going to your other gas appliances such as your cooker before calling out an engineer!
If any of these Vaillant boiler fault codes occur then do not panic! Check the steps & advice listed above and see if you can address the issue yourself. We have expert heating engineers available day and night who will always be happy to give free impartial advice over the phone – if you wish to discuss any Vaillant boiler fault code just give us a call. We can provide quick emergency callouts and fast turnaround times on new Vaillant boiler installation in Bristol and throughout the Southwest.