Economy 7 Circuit

Ian2

Hi - just looking for some advice on the most economical option for our central heating and water heater system.

We live in a flat that is electricity only - there's a thermal store water heater that has 2 immersions, one running on the off-peak eco 7 tariff that clicks on overnight and the other a booster on the regular circuit. We very rarely have to use the booster as the overnight eco 7 immersion provides enough.


We used to have storage heaters that also used the eco 7, but we didn't like the way they worked (i.e. not being able to choose when heat was on/off) so we removed them and have mainly been using a couple of electric fan heaters to take the edge off. This has been okay as the flat is generally quite warm anyway (in a block, relatively new build, good insulation etc)


We now want to install some modern electric radiators though, and are wondering what the best approach to this would be. We've had a quote of £350 to change the old eco7 storage heater sockets to be on the standard circuit so we could just plug the radiators in there but keep the water heater on eco7.


What we're wondering is - might it be more economical to just switch everything to the standard tariff and let the water heater run on that too (and if we chose this option, would we not need the switch over of the circuits, i.e. would the old eco7 circuit just become live during the day)?


Or, should we keep the eco7 JUST for the water heater and run everything else on the standard tariff?


Obviously it's hard to know what's best because we don't know how much extra energy the electric radiators will consume compared to the fan heaters before we get them. We'll be getting 2 x 1100w rads for the living room, 2 x 800w for the bedrooms and a 450w for the hall.


Do thermal store water heaters tend to use a lot more electricity than radiators? The one we have is brand new (installed 6 months ago).


Any advice much appreciated. It seems a lot of people are switching away from storage heaters these days as electric heating gets more efficient, so thought someone may have had a similar experience.


Thanks in advance!

Robin9

Ian2 wrote: »

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We now want to install some modern electric radiators though, ...........................!

Before you go down this route read the many threads on this type of radiator .

AndyPK

I would move away from E7 if the storage heaters have gone. (unless you intend to leave the other heaters on at nite)

Look at your E7 pence per KWH
and what you can get on a normal tarrif 12p? 14p? can't remember

Anyway, E7 for just water won't be worth it.

You will need to get a new timer for the water, so its only on for 1 hour in the morning, and maybe half an hour at night.

e.g.
https://www.ebay.co.uk/itm/Timeguard-TRTM7-Economy-7-Water-Heater-Controller-Off-Peak-Immersion-Timer/130833396790?epid=1255659718&hash=item1e76473436:g:2swAAOSw~gRVi~L5

Ian2

Thanks for the replies.
I think I’ll have to call the electric company and see whether or not I seem to be using most of the energy during the day.

The timer on the water heater is an interesting thing I hadn’t considered though - my worry about switching it from eco7 is that I’d just have and immersion clicking in and out all day on standard tariff. That would be a good solution.

I’ve been reading through the electric rad threads as suggested. Seems the consensus is that they are much of a muchness and will all cost more than storage heaters. We just really didn’t like the lack of control with storage heaters though, and they’re all absolutely massive and ugly - makes a difference in a small flat.

Robin9

Ian2 wrote: »

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I think I’ll have to call the electric company and see whether or not I seem to be using most of the energy during the day.
...........

You don't need to ring them - all the information you want is on your bills.. The off peak and on peak units are separately shown on your bills - it's simple maths to work out what % you use at night.

AndyPK

Or just take readings a week apart.

Richie-from-the-Boro

massive and ugly - makes a difference in a smallish the flat.

It does, about 30%+ more for the cost of your only source of space heating energy, but as you are now direct on-demand only it's unlikely E7 water only heating will consume the 40% night delivered energy use. There are however examples on this very forum of some users achieving a break-even benefit @ 30%.

An easy calc can be had in a minute using your online account to decide to two decimal places your entire 12 months use the day/night % values. Your existing high quality insulation on your E7 PartL standard hot water cylinder will help reduce overnight heat transfer loss (although it's never lost because it heats your house).

Radiative is better than convective so any thermostatic controlled panel heater with a timer will do the job. You are beginning to discover there are other costs associated with disposing of NSH. Best of luck.

1+6

jk0

It amazes me that people are so eager to get rid of storage heaters in the name of control. You can control them if you put on your sensible head.


A friend is going to rent one of my flats with them. He has told me he won't be using them and will just use the direct heaters. I've had to burst that particular bubble by pointing out the direct heaters are of too low a wattage to heat the place on their own.