[Andy65]

Originally Posted by Mac9091

You say it may only be pennies but they all add up.

Just think if eon "mistakenly" took an extra penny from every customer in every direct debit...that's a lot of free money at the end of the year.

And how many people would complain about a few pence, let alone even notice it?

Insignificant and pointless I would have thought, especially when they just add a tenth or two of a penny to the cost of 1 kWh and they'll be reaping it in every hour of the day and night.

[houghtonj957]

@JimL I have exactly the same error in basic arithmetic on around 20% of my bills. The rest of this thread seems to miss the point. I've raised it with E.ON Next and they tell me that their system is automated and not prone to errors.They also say this issue has not been raised before. I don't think it results in incorrect amounts being billed. It just makes it impossible to verify the amount being billed. Nothing to do with rounding, smart meters and all the other things mentioned. It's a simple error in arithmetic that a 10 year old could correct.

[JimL]

@houghtonj957 That statement " system is automated and not prone to errors.They also say this issue has not been raised before" raises 2 questions in my mind
1. The incorrect result of the equation clearly shows an error - so the 1st statement is fatuous.
2. I raised this issue when I started this thread. I also raised it again last week (5/8/24) as a complaint because EON fabricated a previous meter reading (plucked out of thin air) AND got the calculation wrong (again) to boot. So the 2nd statement is a blatant LIE! If you speak to them again about this and they tell you "it's never been raised before" ask them to check complaint ref - 1571464.
Also, the equation error DOES result in incorrect amounts being billed. 2p in my case. Irrelevant you say. The advisor told me EON have 3 million customers. That amounts to £60,000 per month at 2p per customer

[meldrewreborn]

I suspect that if they use a rounded reading one month any inaccuracy will be countered the next or later subsequent months. All the factors in the calculation are static, apart from the readings and the calorific value. If the readings can’t cause any repeated error that only leaves the calorific vale. Now this does drift as the mix of gas gradually changes over time but probably individually computed to each account as the reading dates will differ, although smart meter reads will be more standardised.
I, and many others, are not sleeping too well at the moment, but in future I may return to thinking about this topic as it will likely send me off quite quickly, despite the heat.

[Mailman]

@houghtonj957 @JimL

The figures are correct for my kWh gas consumption as can be seen over the last 7 months on attached picture. Gas smart meter reads are recorded by myself accurately (to 3 decimal places) just before midnight on the day the reads are pulled on schedule. The bills themselves do not show this degree of precision although I suspect that 'rounding' is only done when the final kWh figure is produced and the accounts themselves only show integer values. Even so my billed kWh usage over the last 7 months have matched very very closely with the kWh that I have calculated. The very slight variance is undoubtedly due to the CV being shown to only 1 decimal place on our bills although I suspect that a higher degree of precision is used. Unless you carry out the same degree of precision that I have sadly done 😉, there will be ups and downs each month on your kWh calculations.

[JimL]

@Mailman I think this thread is veering off and muddying the waters from my original complaint/point. Just to clarify (roundings etc have no relevance to any of this) the following equation is a 'cut and paste' from my previous bill
Gas charges for meter *************
15 Jul 2024 883.0 Smart meter reading
1 Aug 2024 884.0 Customer reading
Consumption 1.0 Units (m3)

Yep, I am a REALLY low user.

Unit consumed (cubic metres)
× Volume correction (for temperature & pressure)
× Calorific value (energy in each m3 of gas)
÷ 3.6 (convert from joules)
For you:
1.0 × 1.02264 × 39.7† ÷ 3.6 = 11.8
(The equation - left of the = sign) has no roundings for cubic meters (1.0) and the only variant is the "†Average calorific value shown to one decimal place" - 39.7 in this instance

Now, using a calculator 1.0 × 1.02264 × 39.7† ÷ 3.6 = 11.27745 (or 11.28/11.3 to 1 dec place) NOT 11.8
Simple primary school maths and Eon are getting it wrong
PS - In order to arrive at a result of 11.8, the average calorific value would have to be 41.6 - can't round up 39.7 to 41.6

[Mailman]

Originally Posted by JimL

@Mailman I think this thread is veering off and muddying the waters from my original complaint/point. Just to clarify (roundings etc have no relevance to any of this) the following equation is a 'cut and paste' from my previous bill

We shall have to agree to differ about the roundings issue.

From what I can see from your workings, you are assuming (not unreasonably) that the 'system' is calculating all kWh usage using the meter reads as displayed in your bill (to 1 dp). I am suggesting that the 'system' actually uses the raw meter reads (correct to 3 dp) between meter advances in the calculations. Indeed it was only doing this that I managed to reconcile monthly kWh usage (and hence £ gas billing) to within 1p.

From my perspective the numbers used on each bill display meter reads rounded to 1 decimal place. As you can see from my worked examples stretching back this year, when I used the actual meter reads to 3 decimal places you get gas kWh in agreement with what is shown on my bills. I'm not sure about the precision of the CV used in the calculation as to whether your bill displays the rounded (or truncated?) value to 1 decimal place but uses more precision in the calculation. What I do know is that when I round off at the end of the calculation the biggest error between my own bills (calculated using precise meter reads to 3 decimal places) and Eon Next bills (showing 1 dp only) is 0.15 kWh which equates to approximately 0.9p! The average difference over my 7 months was only 0.005 kWh i.e 0.03p

To give you an example from my latest bill:

Unit consumed (cubic metres)
× Volume correction (for temperature & pressure)
× Calorific value (energy in each m3 of gas)
÷ 3.6 (convert from joules)
For you:
8.3 × 1.02264 × 39.8† ÷ 3.6 = 93.3 kWh ONLY

when you do the calculation as it stands you get 93.8385 rounded to 93.8 kWh (not the 93.3kWh that you see on the bill)

so it looks like I have been cheated by 0.5kWh (approx 3p). Now go back to the table in my previous post where you see that the actual meter difference was 8.255 M3. Now lets see what happens when you use this instead 8.255 X 1.02264 X 39.8 ÷ 3.6 comes to 93.329 which now agrees with what you see in my table in previous post (93.330 kWh) and the result in the above calculation shown on my bill (93.3kWh).

I am confidant that Eon Next are not cheating you or anyone else although it does boil down to bill presentation and the assumptions made in the numbers presented. I am also confidant that Eon Next's back end uses unrounded/untruncated data in the actual kWh calculation but displays a limited display rounding. 👍

In your case it is not the CV that is 'different' but the difference between your meter reads. Your numbers would make sense if the actual difference between the incremental meter reads was 1.046336 M3 which would be shown as 1.0 (rounded to 1 dp). The only way you can be sure is to take your own meter reads for the start/end of the next bill and use those in your own calculation to check as I have done. 🍺

[retrotecchie]

@JimL

I don't have gas but I echo what mailman says about the difference in precision between the actual smart meter reads and the number of decimal places shown on the bill.

I read my electricity meter every day or so and put the numbers into a spreadsheet. When I submit my monthly meter readings online (I don't have a smart meter), the reading is requested as an integer number of kWh. I.e. Ignore any decimals.

My meter reads to 0.01 of a kWh and those are the figures I use in my spreadsheet calculations. I also use the full 4 decimal place values for my Standing Charge and my Unit Rate.

So, my meter may read 72438.97 but for the purposes of billing reads they only want the whole units. I personally round up if the decimal is bigger than .50 and round down if it's .49 or less.

If I put in the integer figures, the error could be 0.01kWh or 0.99kWh which either insignificant or almost a whole unit. Over the course of a year, the maximum possible discrepancy between my spreadsheet calculations and their figures can be no more than 0.99kWh...21p, give or take. And that discrepancy can go either way. More often than not, the error is no more than the average error of 0.5kWh and as my figures are submitted monthly, the total error by the end of a year is usually no more than a penny or two either way. That's an error of 0.001667% on an annual bill of around £1200.

So I completely support @mailman's logic because I know for a fact that the backend calculations for smart reads DO use the actual reading, including the decimals and the full 4 decimal place SC and unit charges , where as manual reads and what is shown on the billing statements just use the integer or truncated/rounded values.

[JimL]

@retrotecchie @Mailman Sorry (I understand the point you're trying to make) but the problem with this logic is that, until this month, since October 2022 Eon have been unable to take smart meter readings (no idea why and no idea why they've suddenly been able to) and I have had to submit these manually every month (significant digits only - no decimal places) and the results of the equation have been consistently incorrect - and Eon can't have used any Kwh value other than exactly as submitted by me. So there's no vague rounding occuring.
It's literally bad maths!
Just for clarification (I may have, previously, stated this) Before the switch to Eon Next (ie. EON) the equation NEVER produced this error (whther they were manual or Smart reads). It ALWAYS matched mine and the maths were ALWAYS correct.

[Mailman]

@JimL

I hear what you are saying - I get it (I think).

Perhaps the example you chose was a wrong one to use maybe:

15 Jul 2024 883.0 Smart meter reading
1 Aug 2024 884.0 Customer reading
Consumption 1.0 Units (m3)

The figure from 15 July was smart and looks to be correct from what you have stated about your low usage.

If I look at the 883.0 m3 reading what would have been the reading to 3 dp? I venture it would not have been 883.000 but actually more likely to be the figure of 882.954 and if it has been that number the actual difference of the meter reads between the 2 dates would have been 884-882.954 = 1.046 actual OR ,as Eon Next has shown on the bill to 1 dp 1.0. Applying the more exact 1.046 in the calculation gives you 1.046*1.02264*39.8/3.6 = 11.829 which rounds off to 11.8 kWh (as shown on the statement to 1 dp)

Maybe you can therefore dig out one of the bills where both reads are marked as 'customer reads' and show the same detail as per the July24-Aug24 bill. Maybe then I'll agree that something is amiss and come round to your point of view that Eon Next are pulling a fast one. 🤔