interesting one!a temporary solution if u can get access to pipe from inside, where the pipe exits the wall - use a hairdryer! I used our sisters (looked cheap - only to be told later its a palomo?something like that £80!i left it on for 1/2 hour in the freezing cold oops) - i used on a pipe at ground floor and it was v effective - but i had access to all of the pipe - you'll only be able to heat at the area in which the pipe exits - keep hairdryer close to pipe - i had a tube to focus heat on the pipe = dont get it v hot though that it melts! depending on length of pipe outside it might take a while - if u have someone else around get them to have a look at every 5mins or so and see how long it takes - would be interesting to know - obviously be careful / keep an eye on the hairdryer so u dont set light to anything.
think this is practical - alternatives are to take pipe off but that could be a pain/wait for thaw/call engineer/- at some stage pipe would need to be lagged/pipe diameter increased so it doesnt happen again
eddie
January 2010