Vaillant 828E boiler. problem please help !

[MustangLady]

I come home from work to no hot water. The boiler seems to have stopped as there is no noise coming from it. I pressed the off/on button and it re-starts itself but stops again within seconds and shows code F26. Is there something simple I could do to resolve the problem or do i need to call an engineer. Do you know what the problem is, any ideas please ? thanks

[ianess]

Is it possible that the water pressure has dropped and you need to top it up? If the gauge is reading 1bar or less there's your problem.
Sorry but don't know what F26 is.

[ianess]

http://www.gasapplianceguide.co.uk/ecoMAX_pro_ installation_and_user_guide.pdf

Looking on the above it seems to be something to do with your fan or your day/night settings but to be honest you should get a professional to check it out.
Good luck.