Baxi 105e EMC problems!

[Stinger]

I have a Baxi 105e and it appears to radiate interference in the region of 14MHz and is affecting my household tv and radio equipment. I have fitted a mains filter so it is not coming out on the mains cable. Does anybody know how to cure this other than using the lump hammer several times? The "control" board appears to have a switch mode psu. This is where the problem is IMHO but I don't want to mess up the board/warranty.

Any ideas out there you bright sparks?

 

[Slugbabydotcom]

A better description of the interference would be appreciated.
Is it constant? Transformer buzz?
Can you relate it to a certain stage of the ignition process?
How do you know its 14Mhz? If you can figure that out you probably know as much as I do about the suppression of spurious emissions.