In some cases, the internal logic of the control unit itself may be failing, requiring a reset or replacement.
No. The boiler will lock out to prevent unburned gas from building up. Do not keep resetting it repeatedly without investigating the cause.
The fan motor may have burned out, or the bearings might be seized, preventing the blades from spinning. viessmann d6 error
Visually inspect the external flue terminal for any blockages. Reset the Boiler:
The error reads as a "Flow Switch D6" or "Strömungssensor" fault . This means the internal flow rate has dropped below the minimum threshold required to safely operate the compressor or electric booster heaters. In some cases, the internal logic of the
Even a small amount of trapped air can act as a blockage, preventing water from flowing freely. This is a very common cause of an intermittent D6 error that appears and then disappears.
Silicone tubes connect the fan assembly to the air pressure switch. Condensation can build up inside these tubes, creating a vacuum or block. This trapped pressure tricks the switch into staying closed even after the fan stops spinning. 4. Wiring and Wiring Harness Issues Do not keep resetting it repeatedly without investigating
Trace the two wires connected to the DE1 terminal for visible breaks. Eliminates hardware wire cuts.
Check the gas supply