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OvO billing (hfc vs m^3.... I think)

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Be grateful if someone could chime in and check my math here.


I woke up this morning to an email advising hat due to an error on OvO's side I was £454.27 in debt and that I should call on Monday to discuss a repayment plan. there was then a second email advising that they have initiated a meter reading dispute.

I had both my Electricity and Gas meters replaced on 06/05/25 so I assumed that would be the root cause of the issue, now I'm not so sure. Smart gas meter gone dumb, old electricity meter incompatible with replacement gas so they were both swapped out. All seemed fine until today.

Have reviewed my account and they appear to have retroactively amended my bills back to last August showing me as being in mounting arears every month since. I also noted that neither of my meters show any readings prior to 06/05/25 when they were replaced, so no record of the manual gas readings I was providing to this point other than on old pdf'd bills.

What I believe has happened is that they have amended my gas usage to reflect a calculation based on hft^3 rather than the m^3 that both my old and new meters were calibrated in.

My revised bills indicate I have used 383.60m^3 and 11,525.89 kWh
By my reckoning 383.6m^3 only equates to 4140.79 kWh 

(383.6 x 1.02264 x 38 / 3.6 = 4140.79 kWh)

If they have converted m^3 to hfc however I get the following:

(383.6 * 2.83 * 1.02264 * 38 * 3.6 = 11718.45 kWh)   
Suspiciously close enough to their 11,525.89 figure...

Now just to make things nice and awkward, they stopped issuing my bills by email in April, reviewing those however I have used to that point 457.57m^3 and 469.58 kWh....

Notes:
  • Volume correction factor = 1.02264
  • Calorific value  = 38
  • kWh correction factor = 3.6
  • m^3 to hfc = 2.83

Regardless of the outcome I'll be switching when my fix is up next month, an 11th hour screw up on a 1 year term that approaches 50% of an annual bill is inexcusable.

Comments

  • Correction below since editing doesn't seem to be a thing:


    Now just to make things nice and awkward, they stopped issuing my bills by email in April, reviewing those however I have used to that point 457.57m^3 and 5193.79 kWh
  • QrizB
    QrizB Posts: 18,185 Forumite
    10,000 Posts Fourth Anniversary Photogenic Name Dropper
    Welcome to the forum. You need to have a certain number of.posts and/or days under your belt before you get edit rights.
    Do you have a photo of your old meter? That should demonstrate whether it was a m3 or HCF meter.
    N. Hampshire, he/him. Octopus Intelligent Go elec & Tracker gas / Vodafone BB / iD mobile. Ripple Kirk Hill member.
    2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 34 MWh generated, long-term average 2.6 Os.
    Not exactly back from my break, but dipping in and out of the forum.
    Ofgem cap table, Ofgem cap explainer. Economy 7 cap explainer. Gas vs E7 vs peak elec heating costs, Best kettle!
  • Yeah, I do actually.

    Murphey's law I deleted a slew of photos from my phone about 2 days ago... including those of my meters thinking I'd never need them again. Fortunately I missed one from the end of March where it shows me 3763.085m^3
  • QrizB
    QrizB Posts: 18,185 Forumite
    10,000 Posts Fourth Anniversary Photogenic Name Dropper
    Yeah, I do actually.

    Murphey's law I deleted a slew of photos from my phone about 2 days ago... including those of my meters thinking I'd never need them again. Fortunately I missed one from the end of March where it shows me 3763.085m^3
    That should be all the evidence you need, then.
    But it might be worth checking your recycle bin, in case the older photos are still there. You might need to evidence some of your old meter readings.

    N. Hampshire, he/him. Octopus Intelligent Go elec & Tracker gas / Vodafone BB / iD mobile. Ripple Kirk Hill member.
    2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 34 MWh generated, long-term average 2.6 Os.
    Not exactly back from my break, but dipping in and out of the forum.
    Ofgem cap table, Ofgem cap explainer. Economy 7 cap explainer. Gas vs E7 vs peak elec heating costs, Best kettle!
  • debitcardmayhem
    debitcardmayhem Posts: 12,717 Forumite
    Part of the Furniture 10,000 Posts Name Dropper Photogenic
    QrizB said:
    Yeah, I do actually.

    Murphey's law I deleted a slew of photos from my phone about 2 days ago... including those of my meters thinking I'd never need them again. Fortunately I missed one from the end of March where it shows me 3763.085m^3
    That should be all the evidence you need, then.
    But it might be worth checking your recycle bin, in case the older photos are still there. You might need to evidence some of your old meter readings.

    Indeed also check the cloud too iCloud/google drive
    4.8kWp 12x400W Longhi 9.6 kWh battery Giv-hy 5.0 Inverter, WSW facing Essex . Aint no sunshine ☀️ Octopus gas fixed dec 24 @ 5.74 tracker again+ Octopus Intelligent Flux leccy
  • The plot thickens, level 1 complaints team are standing by OVO's original assessment... because "math is hard".

    I've sent them a detailed spreadsheet breaking down exactly how I have calculated my usage and how they have done so, they have decided to acknowledge receipt and then completely ignore what it proves.

    They also closed the meter reading dispute with a revised opening reading that was120m^3 higher than it actually was, They have based this assessment on precisely nothing whatsoever, I however have a photo of my meter from December 1st  showing it 12m^3 higher than they claim it was on August 28th. They also tried to convince me that this is in part why I'm allegedly in debt... According to them I have used approx. 1/3 less gas in the past 10 months than previously shown and so I owe more... somehow this makes sense to them.

    If their revised (made up) opening reading is to be believed then I have used a grand total of 12m^3 gas throughout September, October and November in Scotland, with a gas boiler, gas hob and keen home cook... Seems more than a little unlikely... especially when the new meter indicates I used 10.8m^3 in June 2025 alone. 

    Expecting to hear back from level 2 complaints by weeks end, after that I think I'll be talking to the ombudsman regardless of whether OVO figure out how to work a calculator or.
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