Fused spur rating for electric underfloor heating

[HenryCooper]

Builder installed 175w / sq metre in an area 6.7 x 3.5. What should the fused spur be rated at and should it have a contractor as well?

Am I correct in thinking it is drawing just over 17A therefore 13A fused spur is insufficient?

Thanks

 

[telectrix]

dedicated radial in 2.5mm on a 20A MCB. reference method C.

 

[telectrix]

and a roll of A4 paper to print off the lecy bill.

 

[DPG]

Is the spur (aka FCU) getting warm? I would probably switch it off until you have got to the bottom of things.

 

[Mike Johnson]

Is 6.7 x 3.5 the size of the mat or the room? its an odd size for a heating mat.

 

[buzzlightyear]

Builder installed 175w

Are you sure it's that cause 175/230 =0.7amps

 

[Mike Johnson]

Its 175W per sqm therefore you have to multiply the mat area by 175W thats why I asked it the area he quoted was the mat size or the size of the room.

 

[DPG]

6.7 x 3.5 = 23.45
23.45 x 175 = 4.1kW
4.1kW / 240 = approx 17A

Depending, as Mike said, whether this is mat size or room area.

OP, is the FCU ('spur') warm?

 

[telectrix]

OP, is the FCU ('spur') warm?

ask when he's taken the washing off of it.

 

[Dustydazzler]

A room this size would usually be 2 mats split across 2 Spurs / time clicks in my experience