Economy 7... getting my head around it

(30 Posts)
sleepyhead Wed 20-Nov-13 20:40:55

We've just bought a flat in a block without gas, so all electric (I'm going to get a quote out of interest for installing a gas supply in the long run, but that's at least a couple of years down the line).

Meter is eco7. Storage heaters and a cylinder for water. I've never used storage heaters before. We used to run up huge bills with an immersion heater before we got gch in our current place.
The flat has excellent insulation and is surrounded by others so heating shouldn't be too much of an issue and I'm wondering is there some calculation you can make to work out whether you're better on a standard electricity tariff without having to do a few months trial and error?
Our lifestyle: 2 children, dh at home with ds2, I'm at work 3 days out of 7 so we're about a lot during the day. Come April dh will return to work and the flat will be empty 8.30-6 3 days a week.

I'm particularly hmm about whether an overnight heat of the water will last anything like long enough for a family of 4 and whether we'll end up heating a lot of it at the expensive rate.

Also confused at having to predict heating requirements a day in advance...

Any advice from eco7 users past & present?

sleepyhead Sat 21-Dec-13 22:29:29

My main gripe with my, ooh 6 whole days, experience with the storage heaters is that they're too warm so far, although with output down half way that's improved.

I've been taking daily meter readings and our bills at this rate will be about £50 higher than our previous place, BUT that's largely to do with the fact that we're warmer and using more heating. We had our thermostat on the gch set at 18 and the heating was on maybe for 2hrs a day. We'd boost it a bit for sitting around in the evening to maybe 19 or 20. It was also a (large) 1 bed. This is a 3 bed.

With the storage heaters I'd estimate the temperature in the flat at around 21 degrees + all day and night.

I suspect we could easily get away with switching off another storage heater at the moment. Might give that a go.

I've further investigated the hot water cylinder and it does have 2 cables coming out of it each with a wall switch, so presumably one of them is a booster.

DoctorGilbertson Sat 21-Dec-13 15:33:01

I'm on economy7. No gas to the house. Was on a combi boiler/gas heating before.

Seems OK so far re: bills etc.

our nighttime hot water does two showers in the morning and the kids bath in the evening - we never need to use the daytime circuit.

We have a storage heater (well a kind of hot air thing) - it holds heat well but again I agree Feb will be the test. our bills have gone up a lot since we turned the heating on but also the tumble dryer I guess.

I'm tempted by the scottish power rate that does an expensive first however much electricity followed by cheap after that but waiting for the end of the year to see how much our annual use is.

cafesociety Sat 21-Dec-13 15:20:29

'Storage heaters are absolutely shit. We've just replaced all ours with normal electric heaters and come off economy 7. Our heating bill has gone down and our house is actually warm now. We only managed one winter with the storage heaters'.

This is what I did too. Bills are absolutely fine [about £250 for the 6 winter months] and the house is warm. Although I do use a woodburner when the weather is very cold.

Someone I know has one storage heater in a studio flat, and I'm in a fair sized 3 bed place [no heating in bedrooms though, don't like it]. Her bills on economy 7 are awful, and more than double mine.

PigletJohn Sat 21-Dec-13 00:56:33

modern cylinders with modern boilers are sized to heat up in about 20 minutes.

However a modern boiler may be as much as 30kW of power, but your immersion heater is only 3kW so could take about 10 times as long. It is also twice the size of a typical cylinder. However, the immersion heater has a thermostat which will turn off the power as soon as it comes up to temp. So it is normal to set the timer to come on at the start of the off-peak period, and let it run until it automatically turns itself off. A well insulated cylinder does not lose much heat per day.

If you have a large cylinder with off-peak supply, you may find it has two immersion heaters, one near the top and one near the bottom. The bottom one is to heat up the entire system off-peak; the top one is normally switched off, but will give you small amount of full-price hot water more quickly, if you run out during the day. an immersion heater usually has a round cap in black plastic or silvery metal sticking out of the top or side of the cylinder, with a heat-proof rubbery white or glossy black flex going nto it. Never take the cap off unless you have isolated the power and know how to test for dead (before you are).

If you ever find the water is scaldingly hot, then the thermostat in the immersion heater may be either adjusted too high, or faulty. Newer ones have an overheat cutout to trip them off before they can boil. It is very easy to change the thermostat in an immersion heater, but to change the element you should look for an experienced plumber, they can get stuck.

sleepyhead Fri 20-Dec-13 21:30:37

That's good to know. How long should a cylinder that size take to heat up? Just wondering how long I should have it on overnight.

PigletJohn Fri 20-Dec-13 20:49:15

210 litres is nice and big. About two baths worth, or one bath plus a day's other use, as long as you don't wash up every teacup individually.

specialsubject Fri 20-Dec-13 16:54:47

sounds fine. That's good heaters and good insulation for you!

sleepyhead Fri 20-Dec-13 14:27:00

Yes. Output is at minimum all the time. I actually wonder if it's working properly, but it doesn't really matter at the moment because the flat is warm 24hrs anyway (although it's not that cold outside - the real test will be miserable February).

Currently I have only 2 of the 3 storage heaters switched on, and the ones that are on have the input turned down half way and still stay warm right through until we go to bed, plus not cooking us in the am like full charge was.

specialsubject Fri 20-Dec-13 10:09:27

are you turning the output on the storage heaters to minimum before you go to bed? You need to do that to keep the heat in them and make the most of the night time charge. Then turn the output up as you need it.

sleepyhead Fri 20-Dec-13 09:53:50

It's 210 litres.

PigletJohn Fri 20-Dec-13 02:05:50

If you have room, put a red cylinder jacket (or two) round the cylinder to improve the insulation. Wickes is cheapest this year. As well as the pipe insulation.

What size is the cylinder?

sleepyhead Thu 19-Dec-13 23:09:29

There are flats not hugely far away with gas though. This end of the street is an odd spur and for whatever reason they didn't bring the main down here when it was built. I'm going to get a quote as if it was a grand or less then it might be worth getting the supply brought down, assuming no technical difficulty that I'm not aware of.

starofbethlehemfishmummy Thu 19-Dec-13 23:09:24

To pick up on the post about coming off economy seven and the supplier adding the two figures together - not all of them do that. Some insist on changing the meter.

sleepyhead Thu 19-Dec-13 23:06:52

No gas unfortunately or I'd do it in a heartbeat.

There are flats not hugely far away with

MoreBeta Thu 19-Dec-13 22:59:42

Have you rung your supplier to make sure you know exactly when the Economy 7 tariff kicks in? It varies quite a bit by postcode. I know this as I investigated it recently for our house.

Economy 10 I also looked into and it would be great but apparently most suppliers do not do offer that rate any longer.

Put washer, dishwasher, dryer, freezer (if separate from your fridge) on timers so they only come on at night.

I think you will find a wall mounted gas combi boiler and radiators a lot more convenient and cheaper to be honest. Do you qualify for any grants to help you install a new energy efficient boiler? Grants do exist for certain categories of people and certain types of property but not easy to get. Is it worth you, say, getting a two year loan from the bank to have a new boiler and central heating done now as the savings on your fuel bills may exceed your interest costs?

sleepyhead Thu 19-Dec-13 22:45:11

So, we've moved in.

The storage heaters are ok... The flat is roasting in the am, but stays warm all day and night. Even by 11pm the heaters are still luke warm and we seem to have very good insulation which retains the heat.

I've actually turned off one storage heater, turned the input on the other 2 down to half, and we haven't had to use the panel heaters in the bedrooms at all - just leave the doors open during the day so they get a heat up from the storage heater in the hall confused

Hot water seemed to be limitless and amazing... And then I realised it was a bog standard cylinder on a timer that had been set to permanently on. So that's why. I've now reset the programme to come on during th email cheap period at night and then for a couple of hours in the evening. The cylinder isn't blue, it's green and the pipes need lagging so will get on to that.

I've been monitoring our usage, and if we keep using attachments the rate we have so far, we'd be looking at roughly £130pm. That's with the bloody 24hr immersion on though. Hopefully consumption will be way down now I've got it programmed.

Anything else I should be doing?

sleepyhead Thu 21-Nov-13 19:15:53

I love a good spreadsheet, so I think I'll track our bills over the winter against the standard tariff and make a decision in the spring.

I guess once the heating goes off then the potential savings are much smaller for a household like us with few big appliances (no dryer, no dishwasher) that can be used overnight.

Meanwhile I'll start the gas installation saving fund.

That explains why the elderly lady we bought our house from had even fine with storage heaters for 30 years and we could barely manage one year

PigletJohn Thu 21-Nov-13 18:08:42

storage heaters are not too bad if you are at home all day, while they give off their heat, and go to bed early. Many older people like them.

If you are out all day, and by the time you get in they have run down, they are extremely annoying.

FruitSaladIsNotPudding Thu 21-Nov-13 17:59:13

You don't have to use economy 7 if it doesn't work for you. We have an economy 7 meter and npower agreed to put us on a normal tariff - they just add the two figures together.

sleepyhead Thu 21-Nov-13 11:15:56

I've not moved in yet so I can't answer most of that, but from what I remember of viewings the cylinder is blue.

I guess getting a bigger cylinder would help with a (hypothetical atm) water problem if the cupboard could take it?

PigletJohn Thu 21-Nov-13 00:25:56

what colour is your hot water cylinder? (this is not a joke)

What height and diameter is it?

Where do(es) the immersion heater(s) go into it? Top and/or side? What timers has it got? Is the water comfortably hot?

Storage heaters are absolutely shit. We've just replaced all ours with normal electric heaters and come off economy 7. Our heating bill has gone down and our house is actually warm now. We only managed one winter with the storage heaters.

specialsubject Wed 20-Nov-13 22:35:18

your storage heaters will at the least be connected only to the eco 7 circuit, so if left on will charge themselves up when the eco 7 switches on. Of course if you are away they will charge and discharge if left switched on.

more modern heaters do have their own timer switches so you can get round this.

the point about the shower is fair. Probably best to see how you go regarding hot water use. You can calculate the cost of your shower if you know your unit rate and the power of the shower, plus the length of showers of course.

go go go for economy 10!

Maryann1975 Wed 20-Nov-13 21:27:17

We had ecomony7 when ds was a baby. He was a dreadful sleeper, so I used to set the washer to come on at midnight, them when he woke after 2am I would go and throw it all in the dryer and put another wash in if needed. When I came down in the morning it was all clean and dry. Multi tasking, sleeping and doing the laundry. But obviously now the babies are all children and sleep through, this would no longer be an option. We live in a different house now and don't have economy7. We also had gas, so no idea about the immersion heater and how long the water would stay hot for though.

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