Can flex be buried in walls ?

[Blagard]

Observing a friend house being rewired I noticed something that makes me raise the subject question.

The cable in question os part of the central heating control wiring. The wiring centre will be fed from a Fused Connection Unit with a fuse of the correct rating for the cables/flex's on the circuit. From the wiring centre there will be the usual flex's to motorised valves etc., all conveiniently located within a metre of the wiring centre. All normal so far. But the wiring to the programmable thermostat (2 channel device) which has to take a more convoluted route has been first fixed using a 5 core flex. Because that part of the wiring is fixed I would have thought use of cable would be better, perhaps two twin and earth cables running alongside each other.

The 5 core flex will no doubt be buried in a hall wall plaster where is drops from ceiling level to the thermostat. It will have mechanical protection as used for buried cable. But is it permissable to bury flex ?

So far I have some concerns about the electrician employed as he had installed a first floor ring main cable using some holes knocked through walls (in the floor space) by the central heating installer. That in itself was not a problem but having the 2.5mm T&E curled around (in contact with) the 22mm copper heating pipes was not acceptable!

 

[ericmark]

As far as I am aware you can use flex anywhere that twin and earth is used but not visa versa.

Rules about routes and depth plus RCD protection will be same for twin and earth and flex. Only Ali-tube can be used outside the zones. Well SWA could but unlikely to use SWA or mineral cables due to expense.

 

[Taylortwocities]

As Ericmark, plus one of those 5 cores must be an earthed cpc.

 

[17thman]

A supplementary answer to your initial question is that the "ring final circuit" cable, as you put it should definately not be "curled round" and/or in contact with a heating pipe. Get that resolved.