Vaillant · ecoMAX

F.65 boiler fault code

ecoMAX 600/800 series

What F.65 means

Electronic system temperature too high.

Find a Gas Safe engineer

If you smell gas, a CO alarm sounds, anyone feels unwell, or there is an unsafe flame, leave and call 0800 111 999 from outside.

Safe check: Note the code shown on the display. Do not open, adjust or repeatedly reset the boiler. Contact a Gas Safe registered engineer.

Gas Safe registered engineer: The code remains or returns after the step above, or no home step applies; arrange diagnosis by a Gas Safe registered engineer.

Official source: Instructions for installation and servicing ecoMAX · 834177_13GB_042005 · §8.1.3 Fault codes, Table 8.3 Key to fault codes, F.65, p.49