Storage Heaters

[philbrown]

I currently have a single 2.5kW storage heater in my living room, connected to the economy 7 circuit in my house. It gets a bit cold in the winter, so I bought a 3.4kW storage heater for the living room to supliment the 2.5kW one, and a 1.7kW storage heater for the bedroom.

My original plan was to attach the new 3.4kW and 1.7kW heaters to a 13-amp plug and plug it into the mains, using a timer to control when it comes on and goes off. But from looking on the internet, it seems that the 3.4kW draws more current that 13 amps.

Am I right in this assumption? Would it be possible to have the 1.7kW and 2.5kW heaters plugged into the mains, and have the 3.4kW connected directly to the E7 circuit? Or do I need to get an electrician in to fit a couple of E7 terminals?

-Phil

 

[electronicsuk]

You should really have them all on the E7 distribution board. That's not to say you can't run the <3kW heaters off a 13A plug, but as they are relatively power-hungry loads it would be far better to run each on its own radial circuit, as specified in the regs for fixed loads >2kW. Otherwise, there is a risk of overloading your ring final circuit(s), and old/poor quality sockets may also object to a high power load being plugged in for seven hours a day.

 

[JohnD]

In round numbers,the max load you can put through a UK Fused 13A plug is 3kW (3,000 watts). Anything above this needs a dedicated circuit and cannot be supplied from the Socket circuit. Large fixed heaters should not be supplied from the socket ring anyway as they will take a lot of the available power.

Depending on how your meter works,you may have some circuits that are only live during the economy hours, or you might get all your electricity at the cheap rate during the night (which is preferable).

You need to know which you have, or you may be buying expensive peak-rate electricity for your extra heaters. Post some photos of the meter(s) and Consumer units if you are unsure.

Installing extra circuits is Notifiable work (there are legal controls) and it is likely that you will need a suitably qualified electrician if you need extra circuits.

It is possible that your 3.4kW heater can be connected to the existing outlet, this depends on the rating of the fuse or MCB, the size of the cable used, and the rating of the switches and outlet (they are available at 13A and at 20A ratings)

BTW Storage heaters give out most of their heat during the day. If you are out at work, this may not suit you,but you can get (non-storage) electric heaters quite cheaply. These are IMO far more suitable for bedrooms.

 

[philbrown]

Thanks for the replies.

There are two circuits in the house; the main one and the Economy 7 one. There are two separate fuse boxes and the meter has a Normal and Low reading on them.
The Economy 7 circuit only comes on during the cheap rate period. You can hear a click in a seperate box connected to the electrcity meter at this time.
On the meter, there is a small window with an arrow in pointing to whichever counter is being used, so I'm assuming that during the Economy 7 period, all electricty is charged at the low rate, and not just the electricty being used on the E7 circuit.

The new heaters didn't come with cable, so I'll be able to purchase the appropriate one (the manual suggested 85C heat flex, 2.5mm diam, 3 core). I don't know if the current DP switch for the heater is 13A or 20A. I've had a look at the back, but there's nothing to say. but I can always get a 20A one just to be sure.
As for the fuse box, it's got 3 15A fuses in, so that should be OK for the 3.4kW heater. Seems I have another E7 socket in the living room, but it's behind the TV, and would require a few metres of cable to go from where I want to put the new heater to reach it, but that might be an option. Then it would just leave the 1.7kW heater in the main ring, and that's during the night when the only load would be the heater itself, the fridge, and the TV and Sky box on standby.

-Phil

 

[JohnD]

I'm assuming that during the Economy 7 period, all electricty is charged at the low rate,

check that assumption, it's important.

What hours does your cheap rate have?

For the bedroom,I think a normal panel heater would be better than a storage heater (by nightime the storage will have gone cold) unless you are mostly in the bedroom during the day.

 

[philbrown]

Just checked the meter now that it's Economy 7 time, and only the Low digits are moving.

E7 runs from 1130-0630 GMT.

The reason I favour the storage heater in the bedroom is because they give off heat 24/7. The one I've got in the living room has been off for about 16 hours, but is still hot enough to burn my hand if I touch it for a few seconds. The panel heater only provides heat while it's on, and once it's switched off the room starts to get cold again. Plus I tried a panel heater last year in the living room - didn't increase the temperature that much, but almost doubled the electricty bill.

I think I'll have the two heaters in the living room connected to the E7 circuit, even though it means running a thick cable round the room, and have the small heater in the bedroom plugged into the mains using a timer.

Thanks for all the replies. It's been very helpful!

-Phil