Vaillant ecomax pro boiler fault

[gman2050uk]

Hi guys have a fault on my boiler f06 had a look on their site and it says (flow ntc fault) any ideas what this means?

 

[muggles]

It means there's a fault with the flow NTC, probably needs replacing

 

[gman2050uk]

Now for some reason when I switch the boiler on the LCD display does not come on and the boiler sounds like its gonna take of like a motor revving?