What to check, in order
- Don't keep resetting it
Vaillant says this is a case for an expert, and trying to solve it yourself can be dangerous.
- Call a Gas Safe registered engineer
Or Vaillant on 0344 736 0049. Have the boiler's model and the code ready.
When to call a Gas Safe engineer
Vaillant lists a faulty gas valve, circuit board (PCB) or ignition electrode as the causes.
A repair visit will usually check the gas supply, the ignition electrode and the flame sensor.
- Note the model and serial number. They're on a label on the data badge, usually under the boiler or behind the front cover.
- Write down the exact code, and what the appliance was doing when it appeared.
- Check whether it's still under warranty. If it is, the repair may cost you nothing.
Quick answers
What does the Vaillant F62 fault code mean?
When the boiler shut off the gas, it detected the flame going out later than it should have.
Can I fix Vaillant F62 myself?
Engineer only (engineer visit). Start with: don't keep resetting it; call a Gas Safe registered engineer. Vaillant lists a faulty gas valve, circuit board (PCB) or ignition electrode as the causes.
Is Vaillant F62 worth repairing?
Deal with it now. It concerns how the gas shuts off, so it's a safety matter. Have it checked rather than resetting it.
Checked against
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.