Underfloor heating supply

[B1N9S]

Hi,
I am in the process of doing up my kitchen and as above want to install under tile heating. Approx 3.5M squared, 130W per M squared.

The house is a 30's semi and the kitchen has 3 circuits !! ( I think it has been a conversion of outhouses previously ). The circuits are 2 x radial sockets (32A mcb protected) and 1 x Cooker circuit (50A mcb protected).

Would it be OK to run the underfloor heating on the cooker circuit ??

 

[Spark123]

Do you mean do away with the electric cooker and connect it in?
This work will be notifiable to your LABC under part P of the building regs (England + Wales).

 

[B1N9S]

Hi Spark,

Thanks for the quick reply.

Aside from LABC and Part P !! No I won't be removing the cooker, it will be a electric oven and gas hob - as currently installed, but newer !! But I do want to install the underfloor heating !! Which I realise 'should' be notified.

I have read a few posts on here now and I guess a spur would be fine ? Or should it have its own dedictaed supply ?

 

[flameport]

A fused spur from the socket circuit would be the better option. Presumably you will be fitting more sockets anyway?

Connecting it to the cooker circuit will be impossible, as the 50A MCB implies 10mm cable - you won't be able to fit 2x 10mm wires into the terminals of any standard accessory.

Unusual to see 32A radials - what size are the cables?

For that matter, a 50A cooker circuit is way over the top as well.

 

[Taylortwocities]

You'll be needing an RCD on the UFH feed.

 

[B1N9S]

Thanks Flameport, I think I will take a spur from the sockets. I thought the cooker circuit was OK, shouldn't it be 45A rated at the socket outlet ? It is on 6mm cable.

The radials ar also on 6mm !!! Nothing like being safe !!! I could easily convert the two radials to a 1 Ring, would this be preferable ?

I am trying to leave it "as is" and just install a new kitchen TBH, since it then shouldn't be notifiable, just new socket plates etc !! I am not adding any sockets either.

 

[flameport]

6mm cable cannot be safely connected to a 50A MCB under any circumstances.

There is nothing to gain from changing the existing sockets to a ring.

Changing sockets like for like is not notifiable. The heating installation is notificable work.

It sounds as if whoever installed the cooker and socket radials had little or no idea what they were doing.

 

[B1N9S]

6mm cable cannot be safely connected to a 50A MCB under any circumstances.

Now you've got me worried !! As you can guess I am not a sparky.

Why would this be dangerous ? I guess if it was to take a full 50A ?? is that what you mean ? That the cable would heat up and a 50A mcb suggests the circuit is good for that rating, which it isn't ? What rating MCB would you recommend ?

I dont intend running an electric hob, but some else may in the future !!

 

[B1N9S]

You'll be needing an RCD on the UFH feed.

Maybe a dumb question, please be gentle !! can I still spur off the sockets using an RCD.

Can you buy a RCD'd FCU ?? Since I can't put the flooring on a plug.

 

[Kristoff28]

You'll be needing an RCD on the UFH feed.

Can you buy a RCD'd FCU ?? Since I can't put the flooring on a plug.

Here you go mate. Screwfix do them

http://www.screwfix.com/prods/14770/Electrical-Supplies/RCDs/Powerbreaker-13A-RCD-FCU

http://www.screwfix.com/prods/83049/Electrical-Supplies/RCDs/Volex-13A-RCD-FCU

 

[B1N9S]

You'll be needing an RCD on the UFH feed.

Can you buy a RCD'd FCU ?? Since I can't put the flooring on a plug.

Here you go mate. Screwfix do them

http://www.screwfix.com/prods/14770/Electrical-Supplies/RCDs/Powerbreaker-13A-RCD-FCU

http://www.screwfix.com/prods/83049/Electrical-Supplies/RCDs/Volex-13A-RCD-FCU[/QUOTE]

thanks kristoff, got one today from B&Q (gasp all round !!) £25.