Wiring up underfloor heating - PICS ADDED

[Kristoff28]

Howdo all.

Can someone give me an insight into wiring up underfloor heating. Tried
the quick search but it aint working ???

I have installed the warmup wire system which is all in place and taped
to the floor as tiler is coming tommorow morning to lay Travertine
tiles. I then ran the 2 cold cables including sensor cable up inside stud
walling and into loft then back down to thermostat which is situated outside
the bathroom. Tested system through whole process and everything is
fine which came out at 217.3 ohms.

Now im a bit stumped as to how i can get mains power the the thermostat
which will have to be via the loft.

Thing is all mains power to sockets etc come up from under the floor so
i only have the lighting circuit in the loft which i cant use. Shame
really as it would be easy to do then but noting is ever simple eh.

Only solution i can come up with, is that directly under the bathroom i had
to remove a 4 foot square piece of ceiling due to a leaking pushfit and
that has exposed all the mains 2.5mm cabling. Can i split into one of
those mains cables using a heavy duty 30amp junction box ????
This will enable me to run a 2.5mm t&e from JB, up bathroom stud wall,
into loft and down to thermostat.
Only thing is that the junction box wont be accessable and it will be
covered up by new ceiling.

Please can someone give me some advice on the best solution.

Also i know all this comes under part P but all work will be checked out
by qualified sparky when work is complete.

Thanks

Kris

 

[2face]

i usually do these on there own circuit ..

 

[Kristoff28]

i usually do these on there own circuit ..

Direct cable from consumer unit to thermostat mate ???

 

[Taylortwocities]

Can i split into one of
those mains cables using a heavy duty 30amp junction box ????

No, the junction box must remain acessable.

Where will you be putting the fused connection unit for the floor? You'll probably need to fuse it at 3 or 5amp depending on the size of the mat.

What will you be doing about RCD protection for this circuit, and the other circuits in the bathroom?

Also i know all this comes under part P but all work will be checked out by qualified sparky when work is complete.

It doesnt work like that. Registered sparks can only notify work they did themselves. Per the above posts, I suggest you get a competent spark to wire the rest for you.

 

[Kristoff28]

Thought that would be the case with the junction box.Thanks for the info.

The FCU will have to be in the loft by the loft hatch for easy access to it.
The wire system is the smallest available at around 1.5 Sqm as bathroom
is only small so will be fused at 3amp

Whole house is protected via RCD. It was built in 2005.

Ahh right i see. Wasnt sure how the Part P thing worked.
Well iv done the ground work and installed the heater
cable and ran the cables into the loft, so i think i will try and get a spark
to hook it up for me, thats if i can get one that is.

Just out of curiosity, how would you go about it if you had the job ??

cheers

Kris

 

[2face]

i usually do these on there own circuit ..

Direct cable from consumer unit to thermostat mate ???

what do you think ??

pretty sure the OP was asking how to get power to the underfloor heating as he said he wished he could use the lighting for the ease of it.

depending on the size of the mat. but if possible i usually add on its own circuit but some dont bother and spur off the ring.

no matter what the size of the under floor heating is, it is a better install if on its own breaker.

and no why would you connect directly to a thermostat do you know something i dont or trying to make a joke ??? either way not really adding any help to the thread so why bother posting ?

just re read the post you are the OP lol.. sorry thought you was taking the p**s .

 

[Kristoff28]

No John, wasnt taking the ****, electrical is not my thing and to be honest
im not sure what im talking about when it comes to electrics and jargon.

Been a long day and got tiler coming in morning to lay floor and wall
tiles and at the end of my tether. If i had hair then it would be all out
by now I phoned 16 sparkys this week
to see if they could help and all of them are fully booked until late feb,
march time and i aint waiting that long so trying to take it on myself.

Ok say you came to my house and i have already put the underfloor
wiring down and the 2 cold cables and sensor cable have been fed up the
stud wall into the loft. Where would you go from there ???

Please dont say walk away, hahaha

cheers

Chris

 

[2face]

hi kris http://www.warmup.co.uk/pdf/UK-DWS-Manual-V0708.pdf

all the info is here for you m8

i will check later to see if you have any questions ... i am sure between us we can sort it,

i would not see a problem with wiring a floor pack up with the tiles down.

take a few pictures of the wire set up incase the electrician is worried it is not fitted correctly .

 

[2face]

hi kris http://www.warmup.co.uk/pdf/UK-DWS-Manual-V0708.pdf

all the info is here for you m8

i will check later to see if you have any questions ... i am sure between us we can sort it,

i would not see a problem with wiring a floor pack up with the tiles down.

take a few pictures of the wire set up incase the electrician is worried it is not fitted correctly .

the spacing is very important. testing is also important before tiling.

The thermostat should be connected to the main electrical supply via a fuse or circuit
breaker, ‘double pole isolator’ in accordance with the wiring regulations.
The thermostat should be installed within the rooms or area to be heated. In the case
of bathroom installations, electrical regulations prohibit the installation of the thermostat
within the bathroom itself. In such cases, the thermostat should be fitted to the outside
of an internal wall of the bathroom, as close to the undertile heating as possible, for example
in an adjacent airing cupboard.

ref pg 5/21

 

[electronicsuk]

To the OP,

The majority of the information in 2face's post above is simply copied from the installation manual he linked to on the warmup site. That's fine, except not all the information within that manual is correct. There is no electrical regulation that explicitly prohibits the installation of a thermostat in the bathroom, although there are certain limits as to exactly where in the bathroom one can site electrical accessories.

In any case, it seems like the best solution for you would be to spur off the ring final from another room, run up the wall (behind plaster or inside stud wall as appropriate) and then bring back down to an FCU and the thermostat in a suitable location. Alternatively, if the size of the bathroom and the location of sockets in nearby rooms permits, you may even be able to go straight through the bathroom wall into the back of an existing socket and take power from there.

The above is just a rough approximation, exactly how the job should be approached will very much depend on the layout of your rooms, and without seeing the job it will be tough for anyone to give specific advice.

 

[ban-all-sheds]

Whole house is protected via RCD.

What rating?

without seeing the job it will be tough for anyone to give specific advice.

Apart from

 

[Kristoff28]

Many thanks for all your help on this chaps.

BAS, cunning as ever LOL, yep should have planned it better but **** it.

Ive included some pictures to give you a better idea of the set up

Click on pics to enlarge
Consumer Unit





Plaster Board cut away, 2 cold cables and sensor cable coming from
tiles and up into loft space. The cold and sensor cables will be installed
in plastic round conduit to be on the safe side



The larger square cut-out, inside the bathroom was were i had to drill the
cross batten to feed the cables up into the loft.
The smaller square cut-out, outside the bathroom is for the thermostat to
be installed. The dimmer switch and flick switch below the cut-out are for the down lighters and LED's.



Bottom right of the picture, where i am pointing is a socket on the ring
with 1 in and 1 out. Could this be a possible socket to spur off from back
up into the loft ???


But then, when i had a brew and some brain food (Sausage & Egg butty)
i had another look at the set up and if you follow the level to the end,
directly opposite to that in the other room is a 1 gang socket, same hight
as end of level. This i thought might be perfect as all i would need to do
is cut more away of the plasterboard to expose the back of the socket
and spur off from this, though the battens and up the conduit with the
cold cables. Is this my best option or not chaps or am i barking up the
wrong tree ???


Any help would be much appreciated

Kris

 

[2face]

To the OP,

The majority of the information in 2face's post above is simply copied from the installation manual he linked to on the warmup site. That's fine, except not all the information within that manual is correct. There is no electrical regulation that explicitly prohibits the installation of a thermostat in the bathroom, although there are certain limits as to exactly where in the bathroom one can site electrical accessories.

In any case, it seems like the best solution for you would be to spur off the ring final from another room, run up the wall (behind plaster or inside stud wall as appropriate) and then bring back down to an FCU and the thermostat in a suitable location. Alternatively, if the size of the bathroom and the location of sockets in nearby rooms permits, you may even be able to go straight through the bathroom wall into the back of an existing socket and take power from there.

The above is just a rough approximation, exactly how the job should be approached will very much depend on the layout of your rooms, and without seeing the job it will be tough for anyone to give specific advice.

simply makes it easier to link to the manufacturers site were pics are used to explain things.
also simpler for the op to stick to manufacturers instructions as to the site of the stat.
there is no necessity to have it in the bathroom and to be honest might last longer out of the steam and dampness of a bath/shower room.

i always work to manufacturers as well as bs:7671. they usually work hand in hand.
just be careful as lots of manufacturers have not yet added the new legislation into the paper work yet for the 17th changes.

 

[Kristoff28]

John,

Just got off phone from manufacturer, nice chap and said that i can spur
off from an existing ring main (socket) and feed into loft space but it must be protected by a metal clad RCD - FCU unit
I presume its one of these
http://www.screwfix.com/prods/24825/Electrical-Supplies/RCDs/Volex-13A-RCD-FCU-Metal-Clad

From the RCD - FCU i can then run cable to my thermostat.

Must admit, the instructions supplied are rubbish

 

[Kristoff28]

Right, i removed the plasterboard in corner, opposite to switch in other
room and located ring main and back box to socket



Is there anything stopping me from spurring from this socket using 2.5mm
T&E through battens and clipped, up through conduit with cold cables
and into loft to the RCD-FCU ??? Then from RCD-FCU down to thermostat
in wall ???
At least then i can replace plasterboard and my tiler can crack on with the
walls tommorow.

I have took pics of everything i have done so if my tiler can get hold of
his sparky mate he can see what i have done and connect everything up
for me and he wont have to start channeling and knocking holes in my
walls as everything is in loft ready.

Cheers

Kris