Possessed Heater?!?!?!!!

Well not really (I hope!)    ..but its really doing my head in, I can't figure it out.

In the living room we have one of those heaters thats on the wall and plugs in. (dont know the technical name for it)...Last week it was cold and I turned it on for a bit. (Maybe 3 or 4 hours)...Well ever since then its still hot on the outside and its producing minimal heat out the vents....... BUT the thing is switched off by the button on the side, AND its UNPLUGGED by the mains.
Its horrible because I have to keep windows open now or we'll boil...  I have no idea whats going on with it..........Any of you electric buffs know anything or heard of this before? Could it possibly be a glitch with the fuse or what?

My first thought is that you have a storage heater.  These are normally hardwired to an outlet (i.e. not connected by way of a plug and socket), and are designed to make use of the cheap-rate electricity at night under the Economy 7 (or similar) tariff. 

In normal use, power is automatically switched on to the heaters at night, and the elements then "charge" the unit by heating up the bricks.  Power switches off from the timeclock around 7 or 8 a.m., the heat stored in the bricks then dissipates gradually throughout the day.  There is a thermostatic damper control which allows you to control the heat output, and on most of the larger units there is also a separate input control which lets you set how hot the bricks get during the overnight charge period.

It could be that somebody has fitted a storage heater which just plugs into a regular outlet.  Maybe they turned it on and off manually each night.  It's unusual and certainly non-standard, but I've seen it done.

You say that it's still belting out heat after being switched off for quite a while though.  How long?   Storage heaters will generally be cold after 24 hours, a little more if it was fully charged to start and the damper has been shut all the time.  If it's been off for 2 or 3 days, it certainly wouldn't still be hot.

The other possibility is that you have a fan-assisted stoage heater.  These have two separate power supplies: One is the night-only power which charges the bricks as for a regular storage heater; the other is live all the time so that you can switch the fan on any time to help distribute the heat.  If you've disconnected the fan supply but left the off-peak supply on, then obviously the heater will still be charged every night.

You say that it's still belting out heat after being switched off for quite a while though.  How long?   Storage heaters will generally be cold after 24 hours, a little more if it was fully charged to start and the damper has been shut all the time.  If it's been off for 2 or 3 days, it certainly wouldn't still be hot.

Thats the thing though.... Its been well over a week by now.

If you've had the cord unplugged from the wall receptacle for over a week and it's still getting hot, there must be another power source somewhere.  Can you see a second cord emerging and going into another box anywhere? 

What controls are there on the unit, on the top, side, under a flap, etc.?   That might help to narrow down the type of heater.

red on/off button on the side. With a dial 1-6 - under the flap on top is 2 more dials with the same 1-6.  All 3 dials are turned all the way down

That definitely sounds like a storage heater with all those dials, possibly even one which incorporates a separate convector heater as well. 

What are the dials labeled, besides the graduated 1-6 ?    It could be that the dials under the flap are the input and output controls for the storage section and the switch/dial on the side is for either a fan or a separate convector. 

Either way, if you've unplugged one cord and it's still keeping hot, there must be another power source to it somewhere.

It sounds vaguely like the storage heaters we had in our old place. Is this a new place for you, Carly? Because if it's like the ones we had, they cost a FORTUNE to run. We didn't have separate power cords we could unplug, but everything else sounds similar. It was the fan bit that made it expensive because the system HAD to maintain a certain temperature, and it would use electricity at any time of day to do that.

theres 2 wires coming out of it. One goes in an outlet. THe other goes into the wall.
The dials have no names on it just 1-6

theres 2 wires coming out of it. One goes in an outlet. THe other goes into the wall.

There's the answer.  It's a storage heater and the cable which is hardwired will be the one which is supplying power to charge the elements overnight.  Is there a switch on the plate where that other cable connects to the wall?    Or is it a hack job where the cord just disappears into the wall without any sort of box? 

theres a switch on both plates and they are both switched off.

theres a switch on both plates and they are both switched off.

Sorry if this is going to seem obvious to you, but are you absolutely certain?   Assuming that somebody didn't fit the switch upside down, remember that off is up here.

I'm certain
Cause I had to switch it "on" to turn on the heat in the first place

Yep, I guessed that was probably the case, but just thought I'd check to be sure.   

It sounds as though there's a fault in that switch, as in it closed the circuit when you turned it on but hasn't opened it again when you tried to turn it off.   

You could disable the heater for now by going to your electrical disribution panel and finding the board which feeds the storage heaters.   It's most often a separate unit fitted alongside the main board which feeds everything else.  Either turn off the circuit-breaker (which in this case is down for off, just to confuse you!) or pull out the fuse, if you can find which one it is (they're not always labeled, unfortunately).   If you're not using any of the storage heaters at the moment (assuming you have more than the one), then you could just turn off the main switch on that heating board.   

Hi AL Lum Minyum!

I did slightly chuckle at your initial post! but if you don't know you don't know!

Definitley sounds like a storage heater but it's not normal behaviour it seems.

In addition to what Paul says - it also could be that theres some botch job other wiring which you can't see that's causing the issue. Paul, you know what I mean by that, you might 'think' you're looking at what must be the only point of failure but more digging around results in the real point of failure elsewhere and especially where you weren't expecting it to be had the job been done properly.

I'd also suggest to the OP - as I think you are renting? - to call the landlord and get him to call out a qualified sparky to check all is well and fix if necessary. As balmerhon has pointed out, you may have a 'boost' function that's switched on and thus using up normal/day rate electricity units when in reality you dont want that. If the sparky then points to a faulty installation or broken unit - it's up to him to replace - I speak from experience there as I had to do exactly this 18 months ago in my rental property for my tenant!

Hope this helps!
Cheers, DtM! West London & Slough UK!

it wouldnt surprise me if it was something to do with the wiring. The heater is next to the kitchen, and last night the light bulb in the kitchen completly blew up in hundreds of pieces So grateful my daughter was in bed at the time!