Ian_m wrote:

My last system used 2 x 5 core taped together with insulation tape which in
the heat of back boiler all oozed off in the most stickiest mess ever.
Current house has cable ties holding the two wires together.

Yeah, it's not nice stuff when it oozes.

My 6-core + earth cable from TLC showed up today (pretty damn quick!)
and I replaced the dodgy wiring with it instead, with a spot of brown
tape marking the live wires. Much better.