Storage Heaters - How to move the socket!

[LukeG]

Hi - this is my first post so please can someone help me.

I own an old cottage (1790) that has solid walls.

The back upstairs room had a Economy 7 Storage Heater fitted to wall (A). A few years ago this was removed and the wiring was terminated to a blanking plate. The other rooms still used the same Economy 7 circuit to power the overnight heaters.

I now want to reinstate the heater into this room, but on a different wall (B). As the walls are solid, I thought of running a heat resistant cable from the original socket, along the skirting board to the new position of the heater (approx 10 meters of cable needed).

Upon requesting this heat resistant cable from my local electricals shop, I was told that this idea was dangerous and the heater should only have up to 1 meter of cable from the unit to the wall socket, and that by running a long wire around the room to save re-positioning the original socket is dangerous.

Can someone help?? Thanks Luke

 

[Steve]

You shouldnt run flex around skirting boards because:

A. it looks rough
B. Its susceptible to damage
C. Flex is temporary, it shouldnt be permenantly fixed.

Move the outlet to an area closer to the heater. I believe you're allowed to do this without notifying under Part P.

 

[ericmark]

It is common when working in old houses where cable can't be buried in the walls as with modern houses to use heat resistance mineral insulated cable. Know by trade name Pyro.
However there is some skill required in glanding this cable and I know many electricians who would shy away from using it never mind DIY people.
It can have many finishes and if done well does look nice.
There is a cheaper cable which is easier to install called Ali-tube cable it looks similar to mineral insulated cable but the temperature is only 90degC and it does not have the advantage of being able to use smaller sizes. With mineral insulated cable 1.5mm is used for ring main so can be hidden far easier the 2.5mm cable (refers to cross sectional area not diameter).
The standard flat twin and earth cable 2.5mm is only rated at 70degC.
There is nothing wrong with using flex which is also available in 90degC version and being round is sometimes easier to hide.
But you must remember flex is ratted as being visible throughout it's length and if not in free air you may need to down rate.
1mm sq MICC (mineral insulated cable) is rated at 19.5A with dia of 6.6mm and 1.5mm sq is 7.2mm dia and rated 25A this is with LSF outer sheath will be thinner is copper to compare with 2.5mm sq twin and earth which is ratted 22A that is 5.4mm x 10.2mm which is why Pyro is used in old building. However you must also consider what it is laid on and if that can take the temperature OK with stone but may want to avoid wood!

 

[ericmark]

You shouldnt run flex around skirting boards because:

A. it looks rough
B. Its susceptible to damage
C. Flex is temporary, it shouldnt be permenantly fixed.

Move the outlet to an area closer to the heater. I believe you're allowed to do this without notifying under Part P.

Where did he say he wanted to use flex?
And there is nothing to stop one using flex. Unlike twin and earth it is
1) Available in many colours. Including black which is more able to stand UV light so better if exposed to sunlight.
2) Less susceptible to damage and more likely to be displaced than a flat cable. Also because round easier to seal in a standard stuffing gland without having to get special oval seals.
3) Where movement is present it is required for example it is not permitted to wire caravans in twin and earth they must be wired in flex.

As with any wiring it can look neat or rough according to how fitted.

 

[flameport]

... my local electricals shop, I was told that this idea was dangerous and the heater should only have up to 1 meter of cable from the unit to the wall socket

Electrical shops should stick to selling products, not giving out spurious 'advice' to their customers.

Provided the flex is the correct size, and would be secured to the wall, you can do what you initially intended. You only need the heat resistant flex for the short length connected to the heater, but using it for the full 10 metres wouldn't be dangerous (it wuld just cost more than other types of cable).

Another option:
Fix a new outlet plate where the new heater will be installed. Connect this to the existing wiring using twin and earth along the wall either in mini plastic trunking or even just clipped to the wall.

The original blanking plate will need to be accessible, as you will be connecting the cable in there.
The cable or flex does need to be on the surface or in trunking. If you want to conceal it in the wall, there are other considerations including where it is routed, RCD protection or using one of the cables as suggested by ericmark.

 

[chimp]

As above said above your original ideal would ahve been ok but I would go down the route of extending the existng point using twin and earth in mini trunking then using your heat reistant flex for the bit from the FCU of double pole switch to the heater.

Remember you must have double pole isolation close to the heater.