Vaillant F25 error code

[manumadness]

Hi, Im working on a Vaillant and the F25 code is showing after looking in the manual its saying theres a fault with the Vaillant compact thermal module cable harness. Can anybody tell me hoe to replace this.
Thanks:speechless:

 

[diamondgas]

What model Vaillant manumadness :welcome:

 

[diamondgas]

Do you know what F25 is referring too? Have a multimeter? GSR?

 

[jtsplumbing]

Need more information on boiler Model // as lots of vaillant boilers. :bulb2: