Smart Meters vs In-Home Display (IHD) - confused by the readings that do not match up


I'm currently with EDF who recently replaced the gas and electricity meters with 'smart' ones. Today I went out to play with them and see what information they display.

The electricity one (SMETS2 Landis+Gyr E470) seems quite good as it displays lots of information including the balance and amount used, but also the standing charge and tariff price.

The gas one (also SMETS2 Landis+Gyr E470...) I could only get the balance and amount used from it. Should I be able to see the standing charge and tariff price on this one too?

The IHD I have (Chameleon Technology ihd3-ppmid-v3) shows the amount used and the price, but disappointingly I could not find the value of standing charge or tariff price for either electricity and gas.

Confusingly the meters and the IHD show different values for energy used:
  • gas meter - £24.14
  • gas IHD "this month" - £33.83
  • electricity meter - £27.43
  • electricity IHD "this month" - £36.53
Why are the corresponding values different? Is this normal? Which ones are correct?

Finally, the amount used shown on the meters is also confusing. When I took a reading in February the old gas meter showed 4769ft3 or approx. 135m3, the new smart meter shows less at 104m3 ("Meter Index")... As for the electricity one I guess the value must have been reset during the swap as the old one showed about 23,000kWh while the smart one is showing a mere 236kWh ("Total Act Import").



  • gefnew
    gefnew Posts: 865
    Name Dropper First Post First Anniversary
    ihd shows sc for the month as well.
  • Wow. 

    1.  The gas meter is a L&G G470.

    2.  Your supplier will use the final readings from your old meters and it will bill you for energy used up to that date. 

    3.  Your new meters start with an index reading of 00000.

    4.  The IHD gets its tariff information from the ESME and GSME: the meters. For this to be accurate, the supplier needs to send tariff information to your meters. Neither the IHD nor the meters are used for billing.

    5.  You can see the tariff information in both meters if you know your way around the meter sub menus. The IHD will show the tariff information: press the icon bottom right: press Account and scroll through the items.

    A much easier way of seeing your usage in kWh and cost terms is via the free App BRIGHT - PROVIDED the supplier has updated the meters with the correct tariff information. One caveat: the comms hub contains a gas proxy meter which uses a fixed calorific value to convert gas volume to kWh. Any cost information on the IHD will be slightly different from what you are billed for as the supplier uses an average calorific value taken across the billing period.
  • Wow wow.

    Ah yea, the gas meter is a L&G G470 indeed, I clipped the 'G' when taking a photo.

    And I found all the important info buried under Account Info, the tariff price, standing charge and the amount for the billing period for both gas and leccy.

  • kevinl34
    kevinl34 Posts: 4
    Combo Breaker First Post First Anniversary
    I am with Octopus and using a KAIFA MA120B Smart Meter with the original IHD3 unit. I have been tracking the GAS usage on the smart meter recently and comparing it it the Octopus website and android app. I have just found the IHD3 data is showing the usage 1 day later than the actual day the gas was consumed. For example online and in the app my gas usage was 46.81kwh on 1st Feb24, that usage is shown for 2nd Feb24 on the IHD3, each historical reading on the IHD3 is shown for the day after, not the same day as the online and app display. It could be the dates on the online system are one day out but the ELECTRICITY readings  are a direct match, day to day. My other finding is that the IHD3 readings are 1.7% lower than the website and app, very odd.
  • QrizB
    QrizB Posts: 13,640
    First Post First Anniversary Photogenic Name Dropper
    kevinl34 said:
    My other finding is that the IHD3 readings are 1.7% lower than the website and app, very odd.
    That't to be expected; the IHD doesn't know the calorific value of the gas, so can only use an approximate conversion factor.
    N. Hampshire, he/him. Octopus Go elec & Tracker gas / Shell BB / Lyca mobi. Ripple Kirk Hill member.
    2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 30MWh generated, long-term average 2.6 Os.
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