Cheapest way to use the immersion heater

Richie-from-the-Boro

Cardew wrote: »

1. Most cheap rate electricity is around 5p/kWh and the rest is normally 12p-13p/kWh(excluding tier 1)

2. Not all clocks auto-adjust - many switch mechanically - mine for example and Graham's above:


3. You are making the assumption that immersion heaters are always wired on an E7 circuit that only switches on for the 7 hours.(like yours?) Many are not!

My house, and many others, have everything in the house on cheap rate and everything on day rate for the other 17 hours. My cylinder only has the one immersion heater element. So leaving it on all the time as you suggest would mean it operating on both cheap and day rates.

The fact that Roxalana has a timer for the immersion heater(like myself) suggests that her immersion heater is similarly wired.

.1. 5p agreed, my day rate is higher hence the 25%
.2. Don't follow you are you saying your night rate is not automatic ?
.3. See No 2

Yes I'm making the assumption that (1) an E7 system is wired to take advantage of the night rate and that (2) all Part L's have two stats and two elements and (3) the water heater auto switches [ mechanical or electronic ] itself on and off as appropriate.

I've had three different houses over 30 years all with E7 and in each case :

- the water & storage radiators auto switch on and off
- the tank has two stats & elements
- the ' boost ' bit at day rate has been fitted to all three

How old is your system Cardew ?

Cardew

Richie-from-the-Boro wrote: »

.1. 5p agreed, my day rate is higher hence the 25%
.2. Don't follow you are you saying your night rate is not automatic ?
.3. See No 2

Yes I'm making the assumption that (1) an E7 system is wired to take advantage of the night rate and that (2) all Part L's have two stats and two elements and (3) the water heater auto switches [ mechanical or electronic ] itself on and off as appropriate.

I've had three different houses over 30 years all with E7 and in each case :

- the water & storage radiators auto switch on and off
- the tank has two stats & elements
- the ' boost ' bit at day rate has been fitted to all three

How old is your system Cardew ?

1. Roxalana pays 4p/kWh for Night rate and 9p/kWh for Tier 2.

2. Electricity for the whole house switches(automatically) to Economy 7. That switching is actuated mechanically by a clock(in my garage and part of the meter)

Like Graham stated in his post, it is set for the 7 hours from 12:30 am to 7:30am. However that clock never goes forward or back with British Summer Time,(BST) and remains on GMT so after the clocks go forward tomorrow it will be an hour 'slow' and the 7 hours will be from 01:30am to 08:30am. i.e. the clock will still switch at 12:30am but it will be 1:30am - much like you not altering your 7am wake up alarm tonight and as the clocks have gone foward it will wake you at 8am.

http://www.eonenergy.com/FAQ/Meters/Economy-7-Details.htm

The times for the cheap rate period can vary from household to household as they depend on the type of meter and teleswitch you have fitted, and the area where you live. You can find a guide to the Economy 7 times for each area below. Please note that all of the times given can change dependant on GMT/BST.

I would have thought that far more properties have the above arrangement rather than the remote wireless switching that you presumably have in your house.

However I would be very surprised if all the houses you have had over the past 30 years had their E7 times switched remotely.

My house is 23 years old.

Many houses have my arrangement of all electricity on E7 during the 7 hours. This is why people on MSE are always talking of having their washing machine/dishwasher/dryer on in the early hours to take advantage of cheap rate electricity.

Don't forget that years ago the Regional Electricity companies laid down the policy for how houses would be wired and the tariffs available.

Scotland for example offer many timings and tariffs not available in England or Wales.

Certainly many areas have your arrangement of properties wired so only specific appliances got Cheap Rate.

Others like mine have as described above(everything on cheap rate for 7 hours). Taking my immersion heater it has the single supply(24/7) to the single immersion heater. I wired in the timer myself - and used this model.

http://www.alertelectrical.com/prod/1244/horstman-economy-7-quartz-timeclock

You will see it can switch on/off power. Set any timing period and has a timed boost button.

Lastly if any house(as many do) wanted to change from 'normal' electricity to an Economy 7 tariff now, the Electricity company would just fit an E7 meter that switched all the house electricity to the E7 meter for 7 hours - they certainly wouldn't insist the house was rewired and two immersion heaters fitted etc so it had your configuration.

Richie-from-the-Boro

HiYa Cardew, ok your house does auto switch from an electromechanical switch, I've bought three houses over the years two with Horstmann Controlled Economy 7 Quartz E7 nad this one with Horstmann BX2000

- the first was a ' climate control ' non TeleSwitch
- the next two were non climate control TeleSwitch
- - all TeleSwitch means is a radio telemetry timed signal from the leccy board effectively switches the meter from day price to on to night price .. .. and off
- - they could also if they weren't so greedy / tight use the telemetry for reading the meters and real time usage / costs purposes
- - you can see that both units have a one hour or two hour boost function

I'm not disputing that many houses have 7 hours of all their leccy cheap. Your single supply, single element 24/7 immersion heater is the first I've ever heard of and I can see why you wired in a timer. I suspect that your house and others were converted at some point after they were built to E7 and the ones I've owned were intended to be that way from the very design stage long before the founds were dug and bricks laid.

Cardew

Richie-from-the-Boro wrote: »

I'm not disputing that many houses have 7 hours of all their leccy cheap. Your single supply, single element 24/7 immersion heater is the first I've ever heard of and I can see why you wired in a timer. I suspect that your house and others were converted at some point after they were built to E7 and the ones I've owned were intended to be that way from the very design stage long before the founds were dug and bricks laid.

No not so, I had my house built in 1988(conventional wiring) and was offereda 'normal' or an E7 tariff by the electricity company; I chose E7.

Actually after a trial period I found E7 didn't pay(I have gas CH) so changed to a normal tariff. However I still retain the meters and it still switches each day to the E7 meter, but the two readings are simply added together, e.g 500Kwh cheap rate and 2,000kWh day rate are charged at 2,500kWh on normal rate.

Most of the many houses I have occupied have had single supply to the immersion heater. A couple have had an additional 'short reach' immersion heater that just heated the water in the top of the tank; however that was also on a 24/7 supply and not wired into E7.

However you seem to dismiss the point in my last paragraph above.

Lastly if any house(as many do) wanted to change from 'normal' electricity to an Economy 7 tariff now, the Electricity company would just fit an E7 meter that switched all the house electricity to the E7 meter for 7 hours - they certainly wouldn't insist the house was rewired and two immersion heaters fitted etc so it had your configuration.

For 30 years or more, anyone can convert a 'normally wired' house to Economy 7 simply by the Utility company changing the meter. The immersion heater would require modification like mine to ensure that it only was used in the E7 period.

Richie-from-the-Boro

I said my house was, from the design stage like most of the other 6 million homes in the UK was intended to have E7 and wired accordingly, by inference yours was not, and you contradictory response is "" No not so, I had my house built in 1988 (conventional wiring) and ......... ""

Make your mind up Cardew it was converted to E7 from a conventionally wired new build home, you've just said exactly that.

Cardew

Richie-from-the-Boro wrote: »

I said my house was, from the design stage like most of the other 6 million homes in the UK was intended to have E7 and wired accordingly, by inference yours was not, and you contradictory response is "" No not so, I had my house built in 1988 (conventional wiring) and ......... ""

Make your mind up Cardew it was converted to E7 from a conventionally wired new build home, you've just said exactly that.

Make my mind up? Inference? Just said exactly that?

Firstly I don't need to make up my mind as there have been no inconsistencies in my statements

Secondly there was no 'inference' just your lack of comprehension. It is also pertinent to point out that even if there was 'inference' it is hardly the same as saying 'exactly that'.

I will put this in easy stages in the hope you will understand.

1. I had the house built.

2. It has conventional wiring

3. (2) above means it wasn't wired for Economy 7 with Immersion heater etc on a separate electrical circuit.

4. When electricity was being connected to the house for the first time, the electricity company offered me the choice of a 'normal 24/7' tariff or Economy 7.

5. I chose to have economy 7.

6. Therefore it wasn't converted to E7.

Nobody is questioning what has happened with your houses!! I was simply making the point that your assumption that the OP(roxalana) must have the house wired in your fashion could well be incorrect; is that difficult for you to accept?

Similarly her Economy 7 price is not 25% of daytime tier 1 prices.

Also your statement that her E7 timings are corrected automatically might not be correct. Again just because yours are on a teleswitch it doesn't mean that applies to the rest of UK houses.

You still seem to ignore the fact that any house converted to Economy 7 will have exactly the same arrangement as myself.

You seem to find it difficult to accept that this might be the case with Roxalana, and if it is your advice to just switch on the immersion heater and not touch it, would be a costly mistake.

Richie-from-the-Boro

Cardew

Nobody is questioning what has happened with your house!! I was simply making the point that your assumption that the OP(roxalana) must have the house wired in your fashion could well be incorrect; is that difficult for you to accept?

Also your statement that her E7 timings are corrected automatically might not be correct. Again just because your is not on a teleswitch it doesn't mean that applies to the rest of UK houses.

You seem to find it difficult to accept that this might be the case with Roxalana, and my advice is just switch on the immersion heater and not touch it, it works out much cheaper.

I you search for a replacement cylinder for your your aftermarket gerrymandered set up you will see it bears no relationship to legally fitted E7 cylinder.

These boards are here to give an opinion, and I gave mine in #126, you are determined that you are right and no one else should be allowed a view.

I sit on a Social Housing management board and have done for 24 years. With a housing stock of 4700 units I've dealt with many many E7 systems and the water element of yours is a bodge, any reputable plumber would advise against what you are a disciple of.

You have a non BS installation, and a non E7 water cylinder, in turn your controller / auto switching / auto clock does not work, and you have a home made DIY boost timer device fitted. I'm sure there are many other dwellings in the UK that are the same as yours including the O/P's which h/she says has ' woeful ' insulation. The O/P however does have some kind of a timer device I'll await the O/P's response to find out if its a BS spec tank / timer / controller.

Richie-from-the-Boro

roxalana,

The hot water cylinder should be Part L of the Building Regulations spec :

- two thermostatic immersion elements [ one day boost & expensive & one night normal & cheap ] connections
- - the top immersion, which is always on a timer, heats only the small amount water above it and is the expensive daytime boost
- - the bottom immersion heats all the water to the top of the tank and is night-time cheap
- and extra thick factory applied insulation giving improved performance on heat loss
- - typically a minimum of 60mm thick, as opposed to the 30mm jacket on a standard cylinder

My general take is that :

- night leccy costs are 25% of day leccy costs
- the bigger the tank the better
- the clock [ is set correctly ] will auto adjust for summer - winter time
- if you need an extra water heating boost you have a conventional day time cost switch for that purpose already
- switch the E7 water on when you move into the property and leave it alone [ other than extended holidays away from your house ] until you sell the property
- its false economy to switch it on and off

On a different subject :

- water and heat costs on E7, a single / couple out at work all day will use their kWh 60% day 40% night
- a retired couple will be closer to 50 50%

____________________

What sort of water heating do you have ? Can you look at the tank for me :

- does it have two sets of wires [ this is your question about ' the dual kind ' ] one going to the top and the other going to the bottom of the tank ?

What sort of meter / switch arrangement do you have :

- does it have a brand name for example Horstmann

Cardew

Richie-from-the-Boro wrote: »

I sit on a Social Housing management board and have done for 24 years. With a housing stock of 4700 units I've dealt with many many E7 systems .

All that indicates a further 4700 houses could receive incorrect advice!

Richie-from-the-Boro

Cardew wrote: »

All that indicates a further 4700 houses could receive incorrect advice!

I gave my generic view on E7 following ' SnakeDoctor's ' #123, you gave yours, that should have been the end of it.

Then you gave your view on my view in my # number repeatedly. You don't own this group, you don't own me, your house is not in the recognised sense E7 standard.

I initiated my own #126 thread, you have now wasted hours stalking me in my own threads because we differ.

If you have the view that differs from mine or indeed any other person feel free to post it in your own hash number, its your view and its a free world.

:wave: