Are you sure about the quality of the cable to the 13A socket? From the consumer unit, you need to lay a separate cable, a separate cable into the room where your miners are located, and then install sockets. From each 13-16A socket, I consume no more than 2000 watts.
but some miners use 3000w each...
and that is why you need at least a stand along 20amp circuit and socket to mine with
L7
s19
a1166
a1246
as all do 3200 to 3400 watts.
derate 20amp to 16 amp 24/7/365 and 240 x 16 = 3840 watts
but if your voltage drops on a brown out to 208 208 x 16 = 3328 which may trip the 20 amp circuit with constant run
202 volts x 16 = 3232 and your 20 amp breakers will trip
so a 20 amp may be good for the 4 miners above on a hot summer night.
My main farm can sag to 190 volts so I use 30 amp circuits and down clock in the summer.