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MikeE
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August 22, 2020
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Aclara SMETS2 smart meter communication hub lights - what do the flashing sequences indicate?

  • August 22, 2020
  • 111 replies
  • 24883 views

Hi. I used to have a problem with my IHD not correctly monitoring my gas and electricity usage but over the last 2 months, this problem is sorted apart from my gas daily standing charge not being displayed.

This charge still gets paid even though it isn't being shown !

I am starting this topic as the communication hub indicator lights have changed their sequencing.

What used to happen was the SW, WAN, HAN and GAS indicator lights used to simultaneously flash once then go out for 4 or 5 seconds and then the sequence would repeat.

However I have noticed this morning that this has changed with the WAN light flashing 7 times then the remaining SW, HAN and GAS lights flashing once then flashing once more once the 7 WAN flashes have completed.

Anyone else get this ?

Cheers

    Best answer by Jequinlan

    Updated on 03/11/25 by Ben_OVO

     

     

     

    What do the indicators mean on a SMETS2 Comms Hub?

     

    On the front of a comms hub there are a series of LED indicators showing the functional status of the metering system. Each LED has a legend as shown below:

     

    SW - Software

    This shows the status of the hub’s software.

    WAN - Wide Area Network

    Shows your communication hub’s ability to communicate with your supplier. This light will be off if your meter is using the MESH network to communicate.

    MESH - Mesh Communications Network

    If you have a SK2 or SKU3 type of Communications Hub, then both WAN and MESH are active, and will display the slow-flash from these indicators if all is well.

    If you have a SKU1 (85% of houses do), then the MESH indicator will always be off because that section of electronics isn’t present.

    HAN - Home Area Network

    This light shows the connection status of your electricity meter, gas meter and IHD with your communications hub on the HAN (Home Area Network).

    GAS - Gas Meter

    This light tells you if a gas meter is connected. If you don’t have a gas meter installed this light will be off.

     

     

    How fast should the lights flash?

     

    The frequency of flashing relates to the status of the function as follows:

      - Power Up

    To allow the operator to see that all LEDs are working they are shown without flashing for a short period after power up.

      - Error

    Fast flash rate of 2 flashes per second means that there is an error. Call your supplier if this does not change after 48 hours.

      - Transient

    A flash rate of 1 flash per second means that the process is in a transient state such as making a communications connection.

      - Normal

    A slow flash rate of 1 flash per 5 seconds means that the process is in its normal state.

      - Off

    The communications hub is powered down.

     

    We’d expect the lights to flash  of every 5 seconds which indicates the meter is communicating normally.

    In your case it’s the WAN light which is flashing more frequently than usual which could mean we’re having difficulty communicating with your meter. You can check whether this is the case on the ‘Meter Readings’ page of your online account or OVO app (download for Android or iOS). If we haven’t been receiving your readings recently we’d advise carrying out a smart meter health check and contacting our Support Team with the results.

     

     

     

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    111 replies

    Show previous replies
    Firedog
    Super User
    FiredogSuper User
    Super User
    February 26, 2025

    The red flashing light is the meter’s impulse indicator. It flashes once for every Wh recorded, so the flashing rate is higher whenever there’s a bigger current passing through the meter, This is what you’d expect to see when you boil the kettle or make toast, with the IHD showing a red light, too. At other times when not much is happening, the IHD will show a much smaller power draw (in Watts if it’s less than 1000, otherwise in kW), and you’d get bored waiting for the red light to flash on the meter.

    If you really want details, try the following, depending on how easy it is to count the flashes:

    • Count the number N of flashes in a minute. N x 60 gives the average power in watts being used during that minute.
    • Time the interval s in seconds between flashes.  3600 ÷ s tells you the average power in watts being used during those s seconds.
    • Divide the result you get by 1000 to see how much energy in kWh you would use if the lamp kept flashing at the same rate for an hour - e.g. if you had an electric fire running in the house.
    • Multiply the kWh figure by the current unit rate to see what that amount of energy would cost.

    These are the figures the IHD is supposed to work out for you to save you doing the sums. The results are often displayed on the IHD as Now using, in W or kW depending on how big the number is and in £ as the current cost per hour. 

    Noel | I have no official status; I'm just a volunteer who comes here to help other customers. My gear: Aclara SGM 1416-B Electricity-only E7 meter; Chameleon IHD3-PPMID-AAA | It may look as if I know what I’m talking about, but don’t let that fool you. |
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