I'm doing some panelling in the kitchen. Alongside the combi boiler,
two 22mm copper pipes go up through the ceiling, acting as the main
flow and return for the central heating. Two 15mm plastic pipes come
down alongside them, to and from a radiator in the kitchen. Also, next
to the pipes, is the communication cable for the central heating
control box thing (connecting it to the thermostat in another room).

Can I safely box all of these in together (which would be tidiest), or
should I enclose the cable in separate boxing, so it's not right up
against the hot pipes?

Regards
Richard