Help Vaillant 242 Boiler Switch Problem

[poqaz]

Hi I tried google but no luck.I found this forum when searching seems a good place to ask for help.I have an old boiler which is vaillant 242 the green knob for resetting the central heating on or off has broken ond just spins( [DLMURL]http://img148.imageshack.us/img148/898/69800999.jpg[/DLMURL] ) How can I replace this if possible.
Thank you for your help in advance.

 

[stevetheplumber]

you can buy the switch but you have to remove the pcb to fit if memory serves me right should be details in the mi's

 

[poqaz]

Thank you for your help.Since its the weekend I can't get anybody to repair it. Is there anyway I can switch the heating on (being 60yrs old and its cold.) if i remove the button?