Storage heaters using on peak suppli

4 Oct 2010
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Newcastle upon Tyne
United Kingdom
I have two old storage heaters in my flat and I am concerned that they are using on peak electricity in addition to the off peak supply. Two years ago I received a bill for a three month winter period of over £2000.00. I only had the storage heaters switched on for two months (the power switched were continuously on for the two month period). After the bill was paid I didn't use the storage heaters again and spent the next winter freezing cold as I was worried about the potential cost.

I have a Economy 7 meter supplied by Npower, the meter is working correctly and switches to the off peak tariff at the correct times.

I have decided to use the storage heaters again this year as I am now working from home and need the flat to be heated properly. I only have one power switch for each storage heater. I switched the power switch on this morning for the first time in several months and noticed that the storage heater was very hot this afternoon. This means that the storage heater is charging and is using on peak electricity all the time whilst the mains power switch is on.

In order to benefit from the low rate tariff do I need to manually turn the storage heater power switch on at midnight and off at 7am every day?

I have been doing some online research and have read something about radio teleswitches which are supposed to be fitted with the meter so that storage heater can not charge during the day. Apparently with this device they should come on as soon as the off peak supply kicks in so long as the storage heater power switch is on. I don't know if there is a radio teleswitch next to my meter. There is a small grey box with "MEM" written on the front but I am unsure of what this is for.

I have spoken to Npower who couldn't provide any advice and I just wondered of anyone here could help with this query.
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If you have two consumer units, one for off-peak and one for 24/7 supply, then the storage heaters should only be supplied during the off-peak periods. If this is the case then there are only two reasons for your heaters being on 24/7, and those are a fault with your side of the installation, or a fault with the teleswitch/timer/metering for which your supplier is responsible. If you can prove those are at fault then you may be owed a rather large rebate for last winters bills.

If you only have one consumer unit/fusebox, then you will need to fit timers to make sure the heaters only run on cheap rate.

As always, pictures of consumer units and metering would help.
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At £2000/quarter, I think you ought to think about changing the storage heaters:[/QUOTE]

I think this is bad advice. Assuming the heaters in question really are storage heaters, there is no way two of them could have consumed £2000 worth of electricity if running on Economy 7 alone, as they should be.

Even if each heater accepted a massive 20kW charge, 3 months worth of charging during the E7 period at an expensive 10p/kWh would only amount to about £360. This suggests to me a problem in the way the heaters are being supplied, not with the units themselves.

OP, you are 100% certain what you have are storage heaters, correct?
Thanks everyone for all the replies, I have uploaded two photograph to my profile of my meter/fuses as advised.

I can confirm that they are definitely (Dimplex) storage heaters (I have some limited knowledge of heating systems through my job although I had never lived with storage heaters until I moved into my partners flat)

I now only use the one storage heater in the living room as the other heater doesn't work anymore (it is switched off all the time)

Last night I switched the storage heaters main power switch on at midnight and turned it off early this morning. The heater is today releasing heat as it is supposed to. I think I just need to know if I have one consumer unit or two consumer units and if there is only one I will take the advice provided and try and get a timer fitted.

Anna :D
The single C/O to the left is for the electric shower.

So is there definitely a teleswitch there and if there is a fault with the teleswitch is it Npowers responsibility?

Difficult to say from those pics - can you take a shot below the teleswitch?

Where is the meter? Photo of that? Or is it part of that teleswitch (actually, looks like it is). Difficult to see the bottom terminals of the meter.

I don't suppose you have neon indicators on the switches supplying the heaters?

I would assume the two way consumer unit is supplying your heaters, but that would need confirming - can you turn that off and see if the heaters stop working? It looks like it has the incorrect fuses, but that would not prevent things working as they should...

Assuming that two way CU is connected to the switched output of the teleswitch (seperate from the other tails to the other two CU's, then it should be being switched during cheap rate - this would be NPowers responsibilty to sort out.
Last night I switched the storage heaters main power switch on at midnight and turned it off early this morning. The heater is today releasing heat as it is supposed to. I think I just need to know if I have one consumer unit or two consumer units and if there is only one I will take the advice provided and try and get a timer fitted.

Anna :D

You mention a 'main' power switch at the heaters. I assume there is only one per heater, and the storage heaters do not have a second switch to control a daytime boost element from the 24/7 supply?

As per above, could do with that one more photo, but it really does look as if your meter should take care of switching the E7 supply to the small consumer unit on the right.
All the helpful responses are much appreciated.

There is only one wall/power switch per heater, there is no second switch.

The smaller (broken) storage heater that we don't use has a neon indicator on the switch supplying the heater. The large storage heater that we do use has no neon indicator on the switch.

I have put three new photos on my profile. The meter is on the original photos but the new photos should be better quality.

Unfortunately I don't know how to turn off the two way consumer unit. I don't know much about electrics. I might have to wait until I can pay an electrician to come and have a look.

Unfortunately I don't know how to turn off the two way consumer unit.
There is a switch on the right of the consumer unit with a label above it saying "ON". If you push the switch up, there should be a label below it saying "OFF". That's it.

You really should call your electricity supplier and explain the problem.

You actually appear to have 3 consumer units, a large one above the meter, a 2-way one to the right of the meter and a 1-way one on the adjacent wall to the left of the meter. The 1-way unit has had the fuse replaced by a miniature circuit breaker (with a little black switch). It might be that only this 1-way consumer unit is switched by the supply and that could be your hot water immersion heater.

I think it is generally recommended that electrics should have a Periodic Inspection Report (PIR) every 10 years or on change of occupants. If your partner hasn't had a PIR, may I suggest you get several quotes. Often, the electrician will come round to size up the job and should be able to explain to you what you have.

I repeat my suggestion about replacing old storage heaters. Modern ones often include their own timer and have much more control about when heat is released. They can offer electricity savings.
The small one way consumer unit to the left of the meter is for the electric shower. I recently had the fuse replaced with the miniature circuit breaker because I had two fuses which blew while I was in the shower.

Now that I know which is the two way consumer unit I can switch it off and see if it stops the storage heaters working.

Thanks again

Anna :)
The neon indicator should give you a clue ;)

Is the neon on during the day with the switch on?

If so, just contact NPower.

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