SMETS1 Secure Liberty 100/110 smart meter guide for WAN, HAN, lights and buttons: DIY tutorial series

  • 14 September 2020
  • 54 replies
SMETS1 Secure Liberty 100/110 smart meter guide for WAN, HAN, lights and buttons: DIY tutorial series
Userlevel 7

Updated on 08/09/21 by Jess_OVO


SMETS1 Secure smart meters - your guide


This guide is about S1 Secure Liberty 100/110 smart meters. If you have an Aclara S1 smart meter, check our guide here. For information about how S2 meters communicate, please see this guide 


What do the buttons on the keypad do?

1 - Displays cost of consumption and units used on the current day and previous day
2 - Displays cost of consumption in the current week and previous week
3 - Displays cost of consumption in the current month and previous month
4 - Displays historical data comprising monthly units consumed and cost of consumption
- Displays ‘Not Used’
- Displays tariff name, standing charge per day, active rate register(s) along with the consumption and cost per unit recorded in each rate register (Will provide Eco-7 readings: IMP R01 is the night read, and IMP R02 is the day read)
7 - Displays ‘Not Used’
8 - Displays ‘Not Used’
9 - Displays total import and export register values (will provide a total reading after IMP KWH)
0 - Performs display check and then displays date, time, load and CO2 data of the current hour and current day, yesterday, last week and last month (will show 'COMMISSION' instead if meter needs to be commissioned)

- Used for prepayment customers - Switches the display to UTRN(vend) entry mode; serves as backspace key during UTRN(vend) entry; enables Emergency Credit when made available; initiates supply reconnection from ‘READY' state. (Activates vend mode/Used to start reconnection process.)
B - Activates auto scroll display from sleep mode; used to scroll back through a display sequence; initiates UTRN(vend) authentication process; mutes alarm; used to confirm supply reconnection from ‘READY’ state.

Activating 'Boost' functionality on Liberty 110/112 meters

If you’re economy 7 customer with a Secure Liberty 110/112 (5-port) meter  and you would like to activate the appliance that is connected to your fifth terminal during peak hours, you can do so using the smart meter keypad.

You can activate this either on the IHD or the meter up to 10 times a day and it will turn on anything attached to the 5th terminal for 1 hour, this will be charged at the peak unit rate.

To activate the boost function:

  • Via the meter, press '2' on the keypad and press the 'A' button to activate - you'll hear a click when the boost has been activated and your meter display will read 'BOOST ON'
  • Via the Pipit IHDpress 'Dual Fuel' and then tap on the 'Status' button at the bottom of the screen on the electric side of the display.


WAN and HAN:

  • An issue with WAN will affect the ability of the electricity meter (and gas meter, if present) to send us data
  • An issue with HAN will not affect the ability of the meter to send us electricity data, but will affect the gas meter and IHD

What is WAN (Wide Area Network)?


WAN allows an electricity smart meter to send/receive data (such as meter readings) securely through the S1 Communications Hub. It uses a roaming SIM that works on 2.5G to do this - the same kind of data network your mobile phone uses. If you have good 4G signal but no 2.5G in your area, the meter will have no WAN.



This LED light represents if there is a WAN connection. It will also indicate how strong this connection is by flashing between 1 - 5 times before pausing.

  • 5 flashes indicates the strongest WAN connection
  • 1 or 2 flashes indicates weak WAN connection
  • Solid light indicates there is no WAN

What is an S1 Communications Hub?

The communications hub attached to the smart electricity meter is effectively our smart kit's brain. It works a little bit like a mobile phone, using a sim card to allow data to be received and transferred from the smart meters to OVO.

The hub allows for information to be stored, such as your meter readings and energy consumption history. This information is then relayed to the correct meter and will also be reflected through your IHD.

There are two main communication channels used by the hub; WAN (Wide Area Network) and HAN (Home Area Network).

How does WAN work?

Using the sim card installed in the S1 Communications Hub, the member's electricity smart meter will search for the strongest mobile data network in the area. (We call this roaming as the meter is able to pick and choose it's network depending on strength, unlike most mobile phones.)

  • If the electricity smart meter is able to latch onto a network, WAN will be established. This will allow for data to be transferred to between the smart meter(s) and OVO.
  • If a connection is unable to be established, it will be known in the industry, as a 'no-WAN'.

What do we mean by 'no-WAN'?

If there's 'no WAN', your electricity smart meter can’t connect to a network. This means no data can be transferred between the smart meter(s) and OVO.

  • This will mean you will need to provide your meter readings manually. 
  • However, providing your IHD is within the HAN, the IHD will continue to display your consumption as normal.

What do we mean by intermittent WAN?

If the mobile phone network(s) in your area is weak, the WAN connection may drop in and out. This is known as 'intermittent WAN'. In such instances, you will need to wait for your electricity smart meter to establish a WAN connection again. We recommend providing manual meter readings in the meantime.

I think I have an issue with my WAN... What can I do?

If you believe you have an issue with your WAN, go through The S1 Smart Meter Health Check. From this we will be able to identify:

  • If you have WAN and how strong this signal is
  • If the meter has been commissioned and has the ability to communicate with us
  • If a master reset may be able to resolve the issue

What is the HAN (Home Area Network)?


The HAN is a secure network that works in the same way as other wireless systems in the home. It allows the smart electricity meter to communicate with the smart gas meter IHD and Smart Relay (remember: gas meters can’t send us readings on their own or send data to the IHD).

A smart electricity meter uses the HAN to collect the readings/data from the gas meter. It also uses HAN to send information to the IHD and to connect to the Smart Relay. HAN only works if the gas meter and/or IHD is within range.



The HAN light will be solid when the HAN is open - this will activated during install (when pairing the electricity meter to the gas meter and any devices) as well as when pairing an IHD or smart relay via SFE. Once this process has completed, the HAN light will turn off.

What do we mean by 'no-HAN'?

If there’s ‘no HAN’ - the gas smart meter and/or IHD, can’t communicate with the electricity smart meter. This affects:

  • Gas meter - If the smart gas meter has 'no-HAN', it can’t send the meter readings/data back to the electricity meter. In this instance, you would need to provide a manual meter reading.
  • IHD - If the IHD is out of range from the HAN, it can’t display any data from the smart meters.

​​​How do you identify if a device is connected to the HAN?

Gas meters

  • In the bottom right-hand corner of the gas smart meter screen, there is a HAN symbol. The symbol will be flashing or solid:
    • Flashing - This would suggest that the meter is not connected to HAN. In this case, please complete  The S1 Smart Meter Health Check.
    • Solid - This is confirmation that the gas meter has been secured to the HAN. However it does not necessarily indicate that we are able to communicate with the gas meter. 


  • You will need to check the Wifi symbol on the IHD:
    • For Pipit IHDs, see the guide linked here
    • For Chameleon IHDs see the guide linked here


I think I have an issue with my HAN... What can I do?

If you believe you have an issue with your HAN, complete The S1 Smart Meter Health Check. From this we’ll be able to identify:

  • If the gas meter is connected to the HAN
  • If the issue is with a meter or a device (please see processes below...)
  • If the meter has been commissioned


The metrology light


This light can be found to the right of the keypad and will most likely be continuously flashing which indicates there’s power going through the meter. All electricity going through the meter is measured, which is represented by the flashing of the LED. The meter is measuring this in kilowatt hours (kWh) and 3,200 flashes equal 1 kWh.




What to check if you’re off-supply


If you’ve lost supply and it’s not a power cut (check this by dialing 105) it could indicate a fault with your meter or the DNO equipment before your meter.


If the metrology light is off it’s worth checking that your meter is in credit mode - press any key on the meter to wake up the screen. It should then auto-scroll through various screens. The first display shown will be the meter mode either ‘CREDIT’ or ‘PAYG’, if your meter is incorrectly showing PAYG contact our Support Team. If the meter is in CREDIT mode contact your DNO to check the supply to the meter.



What are the dimensions of the Secure S1 smart meters?

Dimensions below are shown in millimetres.

Electricity meter

The dimensions are: H 178mm X W 146mm X D 64mm.

Gas meter

The dimensions are: H 264mm X W 235mm X D 174mm.


That’s your guide to SMETS1 WAN and HAN - leave a comment if we’ve missed anything out!


OVO member but not got a smart meter yet? - Book today!


Interested but not yet an OVO member? - Check out our plans!


54 replies

Userlevel 1

OK, so this is going to be a stupid question but I got  to ask it.


If there is no power (e.g. power cut) is the meter going to go dead too? I mean is there a back up battery or something like that?

I am asking because the guide above would suggest that there is?

“If your supply is off and you’re unsure if this a meter fault or power cut, the metrology light is a good indicator. If off supply and:

  • Metrology light is off - power is not entering the meter indicating a fault with the incoming supply. This means their may be a power cut or issue with DNO equipment, therefore the member should check with neighbours and potentially contact DNO.”

I had that very situation. No power in the house and Metrology light off. I had DNO engineer out and they told me that there is power in the meter. To cut a long story short, it turned out that the meter is set up, unknowing to me, as a pay as you go and there is no credit in the meter.

So, I guess the above guide, that suggests if no power in a house AND Metrology light is off indicates fault with the incoming supply is not correct?

Hi Tim, 

I was merely saying it wasn’t the “right” answer because it means I’ll have a bigger bill to pay!



Userlevel 1

It’s all been quite a mess. Turns out the account we set up in August as DD has been cancelled (apparently something went wrong with “the system”) and it reverted back to how it was originally, which is Pay as you go. We had no idea until coming back home to find no power and no gas. All sorted now.


@Blastoise186 - yes, I can see that now. I assume if there is no power going to the meter (and, obviously, Metrology light is off) it’s probably the whole meter being dead (since there is no power). I think it would still be good to clarify that point, if anyone knows.



Userlevel 6
Badge +1

I’m not sure what the B button shows. Hopefully a more knowledgeable person on here may be able to say. I believe the A and B buttons are generally used for prepay settings.

It may be worth checking your bill for the period when the meter was installed as this should show the final reading of your old meter and then the consumption of the new meter (which usually starts from 0kWh.

If and when your supplier manages to remotely read this meter it is likely that they will get the IMP kWh reading shown on the display by button 9. This assumes that you are on a single rate tariff. I believe if you have multiple rates such as day and night, the individual readings can be seen by cycling through the readings using button 6. It may be worth checking this to make sure there are not two sets of readings that add up to the total (19667) and the using now reading is only displaying the current active rate.

Userlevel 6
Badge +1

Hi @Dc1789 button 9 scrolls through the various readings. The one you require is the number displayed after it cycles past ‘IMP KWH’. This is the import reading.

This SMETS1 meter should now be readable as a smart meter with a lot of suppliers, so if you are still being asked for readings it may be worth looking around to get this automated (and possibly a cheaper tariff in the process!)

Userlevel 7
Badge +4

No worries @Hannahbunve ! I’m glad we managed to solve that puzzle for you. :blush:

I do have some advice that I’d also like to throw in as a free bonus as well. Not least because I like giving people free stuff, but also because it could potentially save you some cash as well.

Economy 7 isn’t always suitable for everyone and it works best if you’ve got things like Storage Heaters and/or you place at least two thirds of your electricity usage each day between the cheaper hours - usually between roughly midnight and 7am but the Support Team will be happy to confirm that and we can help with that on the forum too.

If you don’t meet the right sort of profile for Economy 7 or you don’t use it to the best of the capability, then E7 might not be right for you and you could end up paying more for your electricity than you should. The Support Team can help with calculating whether you’re better off switching back to Single-Rate or staying on Economy 7 and there’s no charge for asking for advice. If you do switch to Single-Rate, this is considered a change of contract and you might be charged a fee - you’ll always be informed upfront and you can always ask to leave things as they are instead.

If you do request to switch to Single-Rate, your Smart Meter can be updated remotely via SMETS Commands, so you won’t need to have it replaced or have an engineer visit to disable Economy 7 mode.

I hope this helps. If you need any more advice on what Economy 7 is or what it means, we’ve got some great guides on the Forum like this one.

But if you’re still confused, feel free to ask. :)

Userlevel 5

No, voltage isn’t recorded by Smart Meters.

Perhaps it should’ve been in the specification. The power is recorded, and is then used by DNOs to assess the loading factors on their transformers.

Thanks - that confirms my impression. Obviously, voltage is measured internally, but it may or may not calculate the RMS voltage from it. I have never seen a power meter that could not display RMS voltage, but it seems that we have managed to specify it. Oh well, that is going to come back and bite us when we want to move to a smart grid.

Anyway, after a day of 250V+, the voltage has settled down back into the 24xV range. I can live with that. 

Userlevel 1

Ahh ok, I get you now.

The metrology light won’t flash at all if there’s no activity. But it should flash if the meter is healthy and there’s energy being measured through it.


Could you snap a photo of the meter (if the tenant grants consent) for me please? It might help us to see what you’re seeing.



Userlevel 7
Badge +4

Perfect, thanks @G_Etch !

Can you try pressing 6 on the meter and seeing if that shows anything interesting. If you get an IMP R01 and an IMP R02 reading, the meter should be running in Economy 7 mode. Let me also call in @Tim_OVO just in case.

Please let us know what happens

Userlevel 1

I have tried that and the meter has gave me a reading for both IMP R01 & IMP RO2. Not sure if that applies to the last couple of nights as the tenant has had no hot water or heating as they are both on the economy 7. I’ve tried to boost the economy 7 on using 2 on the keypad but to no avail.

Userlevel 1

I’ve contacted ovo regarding this problem but they’ve informed me that they don’t have it on their system because the tenant is not an ovo customer. I’ll have to contact the supplier to the property to see if there is anything they can do.


thanks for all your help, much appreciated.

Userlevel 7
Badge +4

No worries. Sorry I got mixed up about the supplier, muscle memory gets in the way there.

If you need any more advice about anything though, feel free to stop by again. These forums are open to everyone even if you’re not with OVO.

Userlevel 7
Badge +4

Hey there @Zalek !

Thanks for the catch. I think the guide was written primarily with Pay Monthly/Credit customers in mind, rather than Pay As You Go/Prepayment customers, since the Boost Forum usually takes care of members on Boost PAYG. If you’ve run out of PAYG credit the meter should usually show you that on the display, but I can see where you’re coming from there. Nice catch!

I’ll go ahead and have a chat with @Tim_OVO about this, as it might be possible to update the guide to clarify things a bit better and hopefully reduce confusion. We’ll keep you posted with any updates.

Thanks for bringing this up! I hope you managed to get the lights back on.

Userlevel 7
Badge +5

Is this a new flat/house which you’ve just moved to, @Zalek ?

Or did this ‘fault’ suddenly occur without warning?

I’m puzzled that you had no relevant message on the meter itself or the IHD.

Thanks. My problem is that the IMP KWH reading (19667}is 2500 units more than the Using Now reading(17188), which is the one everyone has accepted and told me to use till now. As I have just switched providers,using the U N reading, that presumably will mean a serious cost hike. So if I am to use IMP, what is the Using Now reading for? 

Userlevel 5

This may be a stupid question, but can the smart meter display the mains voltage? I have some overvoltage issues, and it would be nice to have a calibrated measurement. (And I know that this is an issue for the DNO, not for OVO.)

Userlevel 7
Badge +4

Welcome @Hannahbunve ! :)

I can definitely see what I can do here. Please could you snap some photos of your meters and pop them in your next reply for me? I’m definitely happy to help you work out what’s going on here and once I know what meters you have, I can provide the right info to make sure you’re getting the right readings.

Userlevel 7
Badge +4

Heya @MrPuds .

As far as I’m aware, I’m not sure it can do that on the meter display itself, or at least not on any smart meters I know about. It’s possible that a SMETS Command might be able to pull that data though.

However, I think the electricity meters used in the UK would be designed for and calibrated to work with the expected 220-250 Volt range that’s mostly present on the National Grid over here. An electricity meter designed for the UK probably wouldn’t work properly in the USA for example, without being recalibrated or modified somehow.

Userlevel 7

Hi @Hannahbunve and welcome to the OVO online community!


Sounds like your Secure S1 meter is (or used to be) Economy 7, in which case our community volunteer @Blastoise186 gives some great advice in how to take the reading - 



If you have Economy 7, you’d also need to press 6 three times to get the Night Reading from IMP R01 and press 6 again to grab the Day Reading from IMP R02.


Have you checked your meter’s reading schedule with the Support Team? Requesting an update to a daily or half-hourly schedule will mean you shouldn’t need to read the meter manually, although we’re on hand here if you notice any communication issues.


If you haven’t already it’s worth checking the usage pages of your online account or OVO app (download for Android or iOS) which shows the usage info we’re receiving from your meters.


Hope this helps - let us know how you get on! :slight_smile:

Oh my..I feel silly 🙈 I have checked pressing 6, and it gives me the reading I need. I didn't realise at all it was economy 7! 


Thank you all for all your help! I appreciate it :)

Userlevel 7
Badge +5

No, voltage isn’t recorded by Smart Meters.

Perhaps it should’ve been in the specification. The power is recorded, and is then used by DNOs to assess the loading factors on their transformers.

If, @MrPuds you have reason to believe that your voltage is higher than the maximum permitted threshold of 253v, then you should inform your DNO. They may be unaware of affects from a recent network change in your locality.

There was a power-outage on an underground cable close to me on 4th March. Since the repairs, the voltage at my house has dropped by about 8v. For me this was good news because it’s been rare than I’d previously witnessed less than 248v during daytimes.


Userlevel 7

Thanks for your answer, it’s not the one I was after mind, but thanks for your time!



Not sure I understand, @Keth - @Blastoise186 has just explained how you can confirm the correct reading showing in that video from the landlord. Is it not the right answer as it confirms a higher reading? 



Userlevel 7
Badge +4

Heya @Carola2611 !

Good question there. The one you’re after is IMP KWH which is short for Import Kilowatt Hours. The other one IMP REG isn’t relevant for submitting meter readings.

Userlevel 6
Badge +1

Much awaited guide Tim - thank you!

A concise, easy to read and can help with some basic understanding of SMETS1.

As I am still waiting for my IHD, I can try to understand use/spend information using the buttons in the interim.

Userlevel 1

If the metrology light is flashing, what kind of fault is usually the cause? I have a liberty 110 meter and it appears that the economy 7 has not energised through the night. Also the boost function on key 2 doesn’t work, it’s just says “not used”. Is there a way around this?