I have to lengthen a couple of runs of lighting (1mm & 1.5mm) T&E to4" 20mm conduit, two Pratley flat T+E glands (rare, but available from TLC) and two threaded adaptors for the glands solvent welded on the conduit. Slimmest containment I can think of - should be fine to let that dangle (the glands will support the joint on the cable) and no need for heatshrink as the insulated crimps will be contained. Fix conduit with a couple of clips for a more solid job.
> reach a boiler connection block that I have had to move. The runs are
> currently clipped to a wall.
>
> Can I crimp and heatshrink wrap the connections and clip securely or
> is it required to put it in a box? It's a bit of an awkward place to
> get at and a box will be a bit of a pain to squeeze in.
>
> I guess if I have to put it in a box I can simply do the crimping and
> wrapping and then put the lot inside a 'choc box'.
>
Next option, though bulkier might be a 3 way Hager-Ashley maintenance free junction box - those have cable grips and mounting screws.