BoilerFaultCodesVaillant D.82 Fault Code
Also written as D82 — same fault.
The Vaillant D.82 fault code means: your boiler is currently checking its systems and preparing to fire up the burner to provide central heating.. It appears on 6 Vaillant models in our database.
Technical description: Burner start up in heating mode
What causes the Vaillant D.82 fault?
This isn't actually a fault, but a status message indicating the boiler is performing its pre-ignition safety checks. It physically occurs as the fan begins to spin and the gas valve prepares to open so the burner can ignite for central heating. If the display stays on this code for a long time without the boiler firing, it may indicate an issue with the ignition sequence or gas supply.
You will see this code more frequently during the autumn and winter months when the thermostat calls for heat more often.
DIY fix possible
No action is required as this is a normal status messageMonitor the display to ensure it progresses to a different code once the house warms upEnsure your thermostat is set to the desired temperature
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Vaillant models that show the D.82 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vaillant D.82 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026