Underfloor heating mystery...

[electric will]

Ok, cable and breaker size will need checking but, 50 amp mcb in original cu, 10mm twin and earth cable to near ontoller, you'll need somewhere to box this in, 4 pole contactor in enclosure, 10mm cable to input terminals linked to all 4, 4 lives to mats connected to output terminals, neutrals all connected together.
run small length of 2.5mm cable from input terminal on contactor to fused spur, neutral to fused spur from same neutral that connects the matts.
1.0mm cable from fused spur to control power in, output from controller to coil in contactor (a1and a2)
3 amp fuse in spur.
whats anyone else think?

 

[electric will]

This will only work if the controller is either on or off. Some control the power to the mat via pulse width modulation. Therefore this won't work with them.

 

[ed-ectrician]

Cheers will!!