Economy 7 and energy usage concerns in new flat

Simelthwate

Hi 

Sorry for the long post. I am not capable of writing succintly due to how my brain works. And I have a lot of questions.

My mum (elderly) and sister moved into a 2-bed all-electric flat approx 7 weeks ago, from a dual-fuel 3-bed semi. They are both at home most of the time and are on an expensive Economy 7 tariff (Eon Next Flex) without a smart meter. Day rate 15.625p/kWh, Night rate 32.143p/kWh, Standing charge 48.564p/day

The flat has an immersion heater, storage heaters (may be 25+ years old) and electric showers. Given the weather, the storage heaters have never been used. The oven/grill are used about twice a week and the washing machine 3 times/week. Most of the cooking is done on the hob or microwave.  The immersion heater is switched on on alternate nights as the hot water is only used for washing up and handwashing so lasts more than one day. The boost is never used. Maybe it's cheaper to turn it on every night anyway?

The first electricity bill (for 30 Apr - 27 May) was about £120 with approx 320kWh day rate (average 11.9kWh/day) and 100kWh night rate (average 3.8kWh/day), so approx 75%/25% day/night split. Up until yesterday, they have used another 250kWh day rate and 75kWh night rate. Total 570kwh day + 175kWh night = 745kWh in 49 days (average 15.2kWh/day)

My mum is concerned about the size of the bills, especially as she hasn't had the heating on at all, and is dreading what they will be like in winter. Coming from a dual-fuel property we have no idea if her current electricity usage and bill size is typical for a 2-bed flat in summer months or how much worse it's going to get in winter. I am also concerned that her immersion heater is being heated partially at peak-rate (see below)

Off peak times and immersion heater
Per EOn call centre, and the MPAN code on the bill, the off-peak times are 00:30 - 07:30 GMT. 
The immersion heater is in the bathroom and has no controls or displays on it. The Horstman Elctronic 7 control panel for the immersion heater is in the hall cupboard. It has a clock on it which can be switched between 'summer' and 'winter', with the latter time showing as one hour ahead of the summer one. See photo.



On Wed night, at 11.03pm I looked at the panel which showed 11.03 Summer, so it was showing the right time. However, the 'off-peak' red light was on. It was not on when I looked at it at 10pm. Today I watched the panel and the off-peak light came on at 10.30pm!

1. Why is the off-peak light coming on 2 hours before off-peak rate starts?  
2. Does this mean the immersion heater is being heated partially (or possibly fully) at peak rates but the system thinks it's on off-peak rates? I just went to listen to it and it did seem to be making a noise but maybe that's because I used the hot tap not long ago. Is there a way to tell if it is actually heating up from 10.30pm? They don't have a smart meter so I cannot check the usage via any apps/IHD.
3. If something is out of sync, who would resolve it? Is it something EOn needs to do or do I need to get an electrician or a heating engineer or a plumber?
4. Will switching tariff, likely to a new energy provider, make matters worse somehow? Or maybe switching will somehow fix the problem?

kWh usage?
Irrespective of whether the immersion is heating up using on-peak rates, does 745kWh usage in 49 days (average 15.2kWh/day) with no heating seem reasonable? My dad was quite shocked when I told him how much my mum was using. If it is a lot, how can I find out what is causing the high usage? Could there be a problem with the meter? All the storage heaters are turned off at the wall so it can't be them I don't think.

Switching tariff
I am looking into getting a cheaper electricity tariff for them as soon as posible, as well as getting modern storage heaters installed before autumn, and possibly a new way of heating the water (e.g. smaller immersion tank, undersink heaters, thermal battery)

1. My first problem is that for the comparison sites I can't estimate how much electricity they will use per year as they were on dual fuel before. If they carry on at the same rate as they have since they moved in I make it about 5500kWh/year. But then with the heating on top, will that double it, triple it? Is there any way to estimate it?

2. I was thinking of getting a smart meter installed by the new supplier so my family can take advantage of smart tariffs straight away, or when the new heating/water heating is installed. However, I'm concerned that because the current storage heaters are old, the current wiring/circuits will also be old and won't be modern enough to be compatible with modern tariffs e.g. Octopus Agile, EOn Smart Saver. I don't know if this is a legitimate concern as I don't understand how it all works. Is it just a case of switching and then finding out afterwards that there's problems, or can I check somehow beforehand?

3. Looking at comparison sites (using 11,000 kWh/year estimate which is probably way too low) it seems that a single-rate tariff would work out significantly cheaper than an Economy 7 for the summer months, given the 75%/25% split currently. I could then move them over to an Economy 7 tariff in time for when the heating starts being used. Is this a bad idea, especially if the 75/25 split is only like this due to the immersion heater erroneously using peak rates and we correct it?

If it helps:

This is a picture of some of the circuits, which includes off-peak and day water heater ones:


This is the meter. It has 4 thick wires and 1 thinner one:

I would be extremely grateful if anyone can offer some advice. We are really struggling to understand what is going on and how to resolve things. 

Thank you

FrugaiMacDugal

The first thing that sticks out is this,

Day rate 15.625p/kWh, Night rate 32.143p/kWh, Standing charge 48.564p/day 

On E7 the night rate is the cheaper rate because of storage heating mainly.

Was the bill you refer to actual readings or an estimate?

If an estimate, how do readings compare to the meter readings?

Did you supply readings to EON and have day/night wrong way round?

Scot_39

1) Off peak times

Beware - their are many meter set-ups that do not use the standard regional timings - like 00:30 to 07:30 (which would be GMT anyway - so 01:30 to 08:30 B/DST )

So Firstly beware of anyone telling you what your E7 times are, not all in some regions - use the same times.

Whilst 7 hours in a solid block - other variants - like 2+2+5 or even 3+4 splits are possible.

I'd probably trust the offpeak light on the switch more than a casual enquiry with customer services given what looks like an older digital install with external timer control.

If you cannot hear anything - at the tank - once hot the water can often be heard bubbling off the element in older tanks - you could try turning on one of the NSH - again you might hear the heater as heats / expands or at a push - you could check the imp flash rate on the meter if suitable access at that time possible (not easy in some flats)  - 3kW for a typical immerion heater on the meter should be a real flash rate frequency changer.

Other options include a live wire detector from a DIY store - or non contact pen / meter if electrically savy.  (DO any of the NSH fused spur switches or HW timer feed switch - have a little led on them ?)

Anyway - 

If you post your region / distributor ID code and  MTC from their bill MPAN(s)

https://www.ssen.co.uk/our-services/service-information/what-is-a-mpan/

or

https://en.wikipedia.org/wiki/Meter_Point_Administration_Number

Their are a couple of knowledgible people who may be able to track down precise timing information - using something called SSC codes and the associated TPR timings - from the region and MTC.

2) Meter

Secondly cannot see your meter clearly - but looks like an older digital generation that needs an external time switch - to set the use of peak/off peak rate - and to actually switch the restricted supply for the NSH / HW immersion heater. 

You can see their is only one live output tail on the meter itself - which will be live 24/7.

If you visit again could you take a clearer piciture or give us the meter type - looks maybe like an Ampy 5235D or similar earlier / later variant.  (May even have been under Landis+Gyr brand - who rebadged ampy models after buyout)

And try to follow the thin grey wire - and supply a photo - if safe to do so - as in the case of the Ampy - that would be the meter's external rate selection input - often from an RTS or electromechanical time switch (which can drift hideously in any case with say power outages as age).  

Which assuming you do have a restricted off peak only feed to heaters and HW tank - as some of the labels on the CU indicate - would also be driving a seperate meter tail to flat CU.

3) Shower + HW

WAter is something many overlook in larger properties - but in smaller modern efficient design flats - or for those like me who avoid higher room temps to save money at current rates - HW can be a significant share of mix.

 

Showering can consume a lot of electricity - and with e7 timing - that may or may not be at your mums peak rate.

A 10m wash under 9kW shower - 1.5kWh - 52p at 35p/kWh. At off peak a lower 23p etc.

Women sometimes with hair care even longer.

And if your mums elderly / infirm - my mum when really started to lose mobility - could often be 20 minutes plus some days  - so upto 3 kWh.

It might very well be worth staying large tank - if the pressure good enough to drive a plumbed in - thermostatic valve controlled mixer shower - instead of the electric so can shower using water mix with the hot charged consistently at off-peak rate?

I am a lowish user and a low temp setting heater - so my HW is in itself about a third annual consumption - almost enough to make E7 viable vs single rate. 

4) Consumption / E7

Use is very specific - 15kWh is higher than some - likely lower than others. But take the cap for 2-3 in 2-3 bed - of 2700kWh electric plus gas - thats over 7 kWh per day - and would normally exclude tap HW (your 3.8) and in many cases shower too - in your mums case possibly for 2 daily (3kWh+) - Edit - and cooking (say 1-2kWh per meal electric - versus gas hobs / ovens).

Many people get hung up on heating - but for me HW+shower is comparable.  Many small flats - especially for 2 - could be similar as well - even het to more normal temperatures.

Electric heating can be expensive - as you are talking about a flat the energy use for heating will hopefully be lower than old gas consumption - but with even E7 off peak 2x the price of gas - it's non trivial.

So modern HHR NSH and a good off peak tariff to drive them - are often your best bet. 

SR at c27p until July vs 15p - and of course any heavy use at peak 35p a killer.

25% wont be enough to make E7 pay in summer.

But chances are even moderate heating - will make it worthwhile.

Ofgem do produce TDCVs for electric - the mid one now 3900 kWh pa - so just under 11kWh per day including winter - I used to be over the old one 4200 (with 1+1 part time way over) single - below new 3900 kWh - but only by running low temperatures (14/15, 15/16 max 17 living room).

But if a decent chunk of the 12 kWh current is say showers at peak times - changing that alone might swing the balance for you to stay on E7 even in summer

4 kWh for HW is not high - for 2 - even for casual use - the tank itself will lose 1-2 kWh depending on size - a waste in summer - additional heat for flat in winter.

 

If recently purchased - given your considering HHRs type improvement s etc - what did the EPC say - for heating energy use ?

If they havent been their long - their might be data as a very rough guide from previous users - at swithc sites like 

https://energy.comparethemarket.com/home

It's accurate for me - but others say not so much - try your mums flat - or a similar one in same block etc.

But its rough - I use about half the energy my neighbour does - every degree - 2 vs 1 occupant  etc etc.

5) Meter old - upgrade due ?

A meter upgrade to smets2 - might be needed - in any case - if meter roughly as expected.

But when it comes to tariff flexibility

You need to remember that heer old NSH likely rely on meter (on smart that would be called ALCS) - with the meter controlled restricted time switched supply matching tariff times - to keep them only charging at off peak - and even if upgrade it probably better to dual wire and keep the charging meter controlled - unless find a compelling tariff / reason not to.

With old NSH tariffs like Cosy or other TOU will generally not offer the same ALCS functionality to reflect the reduced period rates (but you can program newer HHR NSH ones to charge to match if found a really good option - Dimplexd Qs upto 4 periods a day - Elnur ECombi HHRs only 2 iirc).

And if do get one and in a good signal area / location assuming a communal cubpoard - not all are - with older heaters - a switch to Snug Octopus might be a good option for the first winter whilst get a benchmark (before spending £1000+install on larger top end new HHR NSH) - as keeps a cheap 6 hr overnight charge window - but adds a 1 hr boost in afternoon -  to keep old heaters heat lasting better into evening / night time. 

When I got a quote -  it was c30% cheaper off peak than their E7 (9p on snug off peak in my region (EM) vs your mums EOn is 15p - but maybe regional - and even the peak rate was c10% lower than their E7) They couldnt do my meter in their viewable window at the time - might try in autumn after RTS fuss died down if still here.

QrizB

Simelthwate said:

My mum (elderly) and sister moved into a 2-bed all-electric flat approx 7 weeks ago, from a dual-fuel 3-bed semi. They are both at home most of the time and are on an expensive Economy 7 tariff (Eon Next Flex) without a smart meter. Day rate 15.625p/kWh, Night rate 32.143p/kWh, Standing charge 48.564p/day 

...
I am looking into getting a cheaper electricity tariff for them as soon as posible, as well as getting modern storage heaters installed before autumn, and possibly a new way of heating the water (e.g. smaller immersion tank, undersink heaters, thermal battery)

Economy 7 is the correct tariff for an all-electric flat with a legacy meter, storage heaters and a hot water tank. The one you've quoted is not particularly expensive and I'm curious as to why you think it is?

Simelthwate said:

This is the meter. It has 4 thick wires and 1 thinner one:

A better photo would help but there should be an indicationon the meter displayto show when it switches between recording usage at the daytime-rate and Economy 7.

The thin wire should lead to an external contactor, most likely a Protex EHC1 or similar:

https://proteusswitchgear.com/products/100-a-heating-contactor-single-phase/

The contactor will energise the electricity supply to the storage heaters, and to one of the two immersion heaters, when (and only when) the meter is recording cheap-rate energy use.

Simelthwate said:

The first electricity bill (for 30 Apr - 27 May) was about £120 with approx 320kWh day rate (average 11.9kWh/day) and 100kWh night rate (average 3.8kWh/day), so approx 75%/25% day/night split. Up until yesterday, they have used another 250kWh day rate and 75kWh night rate. Total 570kwh day + 175kWh night = 745kWh in 49 days (average 15.2kWh/day)

Are those bills based on actual meter readings that your mum has submitted to her supplier, or are they estimates?

Can you share what her meter readings are?

gambleruk

Just to help out, my economy 7 times when I was with Eon were 10:30pm til 00:30 and 2:30am til 7:30am so sounds similar to yours, when I asked Eon they told me 00:30 til 7:30 even when I tried to tell them they were wrong. I recently changed provider and now my times are 00:30 til 7:30am as they are supposed to be. I am in the North West and use around 11kwh a day during the summer, half of that is heating the Immersion tank for hot water.
To be honest as long as you know the off peak times and set the timers accordingly then there is no problem.

Robin9

Can we talk about the hot water tank - often located in the airing cupboard.

There will be two electrical supplies to this  - one connected to the top of the tank, the second to the bottom.  The one at the top should be switched off -  this is the daytime booster and should rarely be used as it uses the higher rate. The bottom should be on -  this uses the nightime rates.   

If this is a modern tank with a cream/white jacket it will be well insulated and barley warm to the touch.  The older copper ones used to be fitted with a loose jacket.

QrizB

Robin9 said:

There will be two electrical supplies to this  - one connected to the top of the tank, the second to the bottom.  The one at the top should be switched off -  this is the daytime booster and should rarely be used as it uses the higher rate. The bottom should be on -  this uses the nightime rates.   

You can see the two supplies as two separate circuit breakers in the fuse box - "water heater day" and "water heater off-peak".

You could flip the "water heater off-peak " breaker down and disconnect it for a few days. This should mean that only the off-peak heater gets power.

This is the meter. It has 4 thick wires and 1 thinner one:

The meter looks quite like an Ampy 5235? If it is, the screen will cycle through reading rate 1, rate 2 and the total reading. The active rate number (for the rate that applies at that time) will flash.

Note that 1 is not necessarily the day-rate, and 2 is not necessarily night; they can be the other way around.

There's a short video here that illustrates this type of meter nicely.

https://m.youtube.com/watch?v=8vfjAX_3blI

Scot_39

@QrizB

Yes that was the first model I thought of from the outline as well.

Lets hope the OP can come back with actual model.

But if it is the 35 - the fifth wire is an input - its a timing slave meter (not a timing master - so not an output to a contactor like the Proteus ECH-1 I have from my 4 port smart) - so its an input - pull to neutral on -N model (or pull to live on -L) by switch (often RTS, sometimes old electro-mechanical) to select off peak register.

https://www.solartradesales.co.uk/Cache/Downloads/L-and-G-5235-User-ManualBrochure-info.pdf

And there is only one 24/7 live tail - so some where not in photos - there is something controlling the time and switching the off peak supply

Qyburn

Need to get to the bottom of the Day / Night rates.  Are Eon really billing them round the wrong way, or was that a typo in the first post?

Secondly the daytime usage seems really high. That needs to be looked into and the culprit(s) tracked down.  Has it been confirmed that the meter is correctly assigned, make sure they're not being billed for another flat?

Spoonie_Turtle

Qyburn said:

Need to get to the bottom of the Day / Night rates.  Are Eon really billing them round the wrong way, or was that a typo in the first post?

Secondly the daytime usage seems really high. That needs to be looked into and the culprit(s) tracked down.  Has it been confirmed that the meter is correctly assigned, make sure they're not being billed for another flat?

Not necessarily, easily potentially accounted for by two people using an electric shower - will be helpful for OP to find out how often and how long they shower.

(But checking meter correctly assigned is always a a good idea, just to make sure.)

Scot_39

The rates are easy to check as the QRizB response if it is the 5235 As rreading toggles (rate) 1reading - or (rate)2reading - the smaller 1 or 2 flashes as it alternates between the two registers - indicating the active rate - then a simple check against the 15p and 35p billing absolute readings.

75% peak isn't overly strange in summer. 

I only hit c50:50 in summer on average - and thats on 3 way split E10 with 5 hours off peak during the day too. If I use my electric cold fed shower or use cooker outside my off peak (00-05:00. 13-16:00 GMT and 20-22:00 GMT windows) - then I - and its getting too often - dont even hit the 50% that day. 

And as my longer post above - with the risk one or both are showering outside E7 hours - can be the difference between e7 good and e7 bad - over summer.  

So IF (and we dont know - its just me sepculating) it was in part 2 showers in the peak 

- they are currently at 3.8 / 15 total - shifting say 3 kWh for 2 showers (if not already in that 3.8 - I would suspect not for at least both)  

- would put them closer to 7 kWh /15 kWh - easily enough to make E7 pay.  

And as above post - thats around 30p/day per 10min shower at peak more expensive. Over a year - £100+ each ?

So might make some bathroom work payback quite quickly - depending on layout - at least if have pressurized HW supply already