HI All

There's a heck of a draft blowing out of my Consumer Unit !
I'd always known that the area where the CU is is a bit chilly - but
it's suddenly dawned on me that there's a fairly large hole that
connects the area into which the cables travel to the CU, and ,
eventually, the eaves of the house....

Net effect of this is that the wind's blowing out of the CU !
I'd like to stop this....

Now I know all about expanding foam and canoes g - but I wondered if
a carefully-aimed 'shot' of the stuff into the hole in the wall where
the mains cables enter the CU would do the trick..... -
but there's something in the back of my mind about expanding foam
and PVC not getting on well together....

So - anybody know if they are safe together, or could suggest an
alternative 'hole-blocking' substance. It's a fairly big aperture -
lots of cables coming through it - ordinary mastic wouldn't do it!

I do realise that this plan of action would make life a bit
complicated for anybody who wanted to add extra circuits to the CU -
but I don't think that's going to be much of an issue...

Thanks in advance
Adrian