In reply to Smiffy:
Persevere and you will get the fit right. Some suggestions:
- Rather than two pairs of socks just wear one pair. Two pairs are usually too warm and the warm moisture (yuck!) is likely to exacerbate any rubbing / blister problems. The boots should be well enough insulated for most UK winter days and alpine summer. Also, try different socks.
- Fine tune the lacing. You should be able to adjust the lacing sections so you can still wiggle your toes / have toe and foot spread space but also crank down the heel so it doesn't lift.
- In B2 / B3 boots take slightly shorter strides than you usually would with walking boots / approach shoes as they have far less 'rock' and, of course, are stiffer so normal length or longer strides tend to exacerbate the heel lift.
- If lacing does not work, and give this lots of experiments first, try different insoles / volume adjusters.
- If all else fails and the problem is only a small niggle consider taping or blister plastering the offending heel before going for a day out.
Have fun