SMETS 1 Meters

Types of Smart Meter

There are two main types of smart meters – the older models known as SMETS 1 (Smart Meter Equipment Technical Specifications) and the newer versions that were rolled out in 2018, known as SMETS 2.

Most of these communicate with your supplier through the 2G/2.5G mobile network and contain a normal mobile phone type sim card. Unfortunately a number of different unlinked systems are used to manage these meters and so if you change suppliers it is likely that your new supplier will not be able to operate your Smart Meter and it will become a 'dumb' meter for operational purposes.
However most of these are currently being upgraded to work with the central DCC system which will allow smooth switching between suppliers.

Wide Area Network

The Smart Metering Wide Area Network (SMWAN or WAN for short) is the name given to the communications network between the communications hub sitting on top of your electricity meter and the company responsible for collecting the data and passing it on to other businesses such as suppliers.


Current Smart Meter installations are for SMETS 2 and a small number of SMETS 1. Once SMETS 1 stocks have been used up no more SMETS 1 meters will be installed.

Moving SMETS 1 meters to DCC

As SMETS 1 meters where originally installed on different management systems, they often failed when transferring between suppliers and stopped communicating. Having got DCC and SMETS 2 meters working, it was decided to upgrade the SMETS 1 meters to allow them to be managed through DCC. This would then allow them to operate correctly for most functions including sending meter readings and switching supplier.

The upgrade process involves updating the meter's firmware remotely and making changes in the old management system and in DCC. The migration process to the new DCC SMETS 2 system is called Enrolment and Adoption (E&A).

This does not change the radio communication technology, so if your SMETS 1 meter does not communicate currently it cannot be upgraded. In this case your supplier may eventually install a SMETS 2 meter if there is a SMETS 2 radio signal.

If you are wondering if your SMETS 1 meter is going to be upgraded, look up your meter model number in the table below.

SMETS 1 Meter Models for adoption by DCC
Manufacturer Model ESME / GSME Type
Aclara SGM1312 ESME
Elster AS300P ESME
Elster BK-G4E GSME Diaphragm
Elster BK-G4E GSME Diaphragm (EI5)
Floridan G4SZV GSME Diaphragm
Itron EM425-UK ESME
Itron RF1 sV ZB GSME Diaphragm
Landis+Gyr E470-5299A ESME
Landis+Gyr E470-5394 ESME
Landis+Gyr E6VG370 GSME Ultrasonic
Landis+Gyr E6VG470 GSME Ultrasonic
Secure Meters (UK) Limited EG4v10 GSME Diaphragm
Secure Meters (UK) Limited EG4v11 GSME Diaphragm
Secure Meters (UK) Limited EG4v15 GSME Diaphragm
Secure Meters (UK) Limited Liberty 100 ESME
Secure Meters (UK) Limited Liberty 110 ESME

When will SMETS 1 meters be connected to DCC?

The original milestones have been delayed a number of times and the proposed dates are shown in the table below.

By 7th January 2022 7,217,541 SMETS 1 meters had been migrated to the DCC's systems.

DCC expect the migration programme to complete by September 2022.

Plan to connect SMETS 1 meters to DCC
Meter Manufacturer Start Complete
Secure January 2021 Expected March 2022
Elster Started Planned October 2021
Aclara Started Planned October 2021
Itron Started Planned October 2021
Landis+Gyr May 2021 Expected September 2022

(Page updated: 2022-03-25)

Questions & Answers

What is the accuracy of Smart Meters?
Smart Meters have to be approved under UK law to a certain accuracy. The accuracy is defined as the MPE (Maximum Permissible Error) class.
  • Electricity Meters: MPE Class A
    • ± 2.5% at 1 amp
    • ± 2.0% at 20 amps.
  • Gas meters: MPE Class 1.5
    • ± 3%
Many electricity meters fitted achieve the higher standard of MPE Class B (± 1.5% at 1 amp and ± 1% at 20 amps).
All meters will have the accuracy class printed on their front face. (Updated: 2022-01-16)

What is the SMETS1 end date?
The government are keen for all SMETS (Smart Meter Equipment Technical Specifications) smart meters to interoperate on one system so customers can switch suppliers easily. To encourage this they are discouraging suppliers installing the older SMETS1 meters and incentivising them to move to the new SMETS2 meters. If suppliers wanted the installations to count towards their government targets they could not install SMETS1 meters (or upgrade firmware to SMETS1) after 5th December 2018. Note that some suppliers had a special dispensation and were able to carry on until 15th March 2019.
Additionally due to the extra complexity of prepayments meters, the end date for them was 15th March 2019.
However, suppliers can still install SMETS1 meters if they wish, but it will not count towards their government targets. They may do this to use up old meters stocks or where the customer does not yet have a signal from the new DCC system. (Updated: 2020-02-09)

Are smart meters safe?
Yes. Smart meters are subject to the same safety regulations and testing of any in-home technological devices, including baby monitors and mobile phones. Additionally the meters are secure having a security system developed by industry and government experts including GCHQ's National Cyber Security Centre. A side benefit is that many safety problems are being spotted in peoples homes during installation of the smart meter which would not have been spotted without a visit. (Updated: 2019-10-21)

When will my SMETS1 meter operate again?
The upgrade and transfer of SMETS1 (Smart Meter Equipment Technical Specifications) meters into DCC's systems is planned to occur between June 2019 and the end of 2022.
For more information see Enrolment and Adoption on DCC's website.
Provided your meters are on the list of meters which can fit into this process on table SMETS 1 Meters for adoption by DCC they should start working again during that transfer period. (Updated: 2021-12-06)

How are they tested for accuracy through their life?
Smart meters fall into the MID scheme (Measuring Instruments Directive) which means they are certified at their introduction to market as being accurate but are not given a certification period as traditional meters used to be. Their life depends on their performance during MID In-service testing (IST). The Office for Product Safety & Standards gathers samples of meters from suppliers, if they prove to be in-accurate that type/age of meter will be replaced in customer premises. (Updated: 2019-08-23)

Does my SMETS1 meters have to be replaced?
In early 2018 the government and industry agreed to build interfaces which allow the earlier SMETS1 (Smart Meter Equipment Technical Specifications) Smart Meters to be moved to the new DCC system supporting SMETS2 meters. This means that, although you may have lost Smart functionally when you changed supplier, when it is enrolled into the new DCC system that functionally will come back, and you’ll be able to change suppliers without technical problems. The process of moving the meters across system is called enrolment and adoption.
See our Technical page for a list of SMETS1 meter types that can be upgraded. (Updated: 2021-12-06)

Can my supply be turned off remotely?
Smart meters have the facility to remotely disconnect and reconnect both the electricity and gas supply. However, most suppliers seem to have decided it is too dangerous to remotely disconnect or reconnect, as in the case of disconnection they cannot always be sure that the customer isn't relying on a supply for serious health reasons and in the case of reconnection the customer may have left a cooker on for example. (Updated: 2015-01-23)

How much data is stored on a Smart Meter?
The SMETS2 specification requires the following data to be recorded and stored.
Half-hourly electricity data:
  • 13 months of consumption (Active Energy Import)
  • 3 months of active energy exported
  • 3 months of reactive energy imported
  • 3 months of reactive energy exported.
Gas data:
  • 3 months of half-hourly consumption
  • 13 months of monthly consumption.
(Updated: 2020-11-07)

Do Smart Meters use 5G?
No Smart Meters currently use 5G. Even in the future a move to 5G is unlikely as the amounts of data transferred are very small and long distance communication is the main requirement. 5G is a higher frequency technology and generally low frequencies are most reliable and capable of penetrating obstructions like buildings, which is why 4G will often work in more places than 5G. Higher frequencies are also more easily scattered by objects. (Updated: 2021-04-07)

Can I lay a cable to help join the devices together?
The meters and IHD (In Home Display) can only be joined through a radio link. This applies to all three standards of meters pre-SMETS, SMETS1 and SMETS2. However, one or two suppliers may be able to offer a zigbee booster, this is similar to the wireless booster you can buy for your home broadband and just plug into a power socket.
Our recommendation would be to let your supplier sort it out, as a communications hub (868MHz) with better reach will be available to suppliers to install with SMETS2 meters where needed from mid 2020. (Updated: 2020-02-09)

What is the gas mirror?
Communications from the comms hub on the electricity meter to the gas mater can be slow and may drop out sometimes. To make the system more efficient the engineers came up with the idea of a "Gas Mirror" which is to keep a copy of the gas meter software in the comms hub.
Any changes such as new firmware destined for the gas meter are transferred to the "Gas Mirror" first and then sent to the gas meter over time. (Updated: 2020-10-24)

Can smart meters be upgraded?
Smart meters can have a firmware upgrade just like your computer or mobile phone. The upgrade will be used to fix faults and add new functionality and should be carried out in the background with little impact on the customer. Indeed this feature is being used to allow SMETS1 meters to be upgraded for the SMETS2 systems; this will allow them all to interoperate. (Updated: 2019-10-21)

How does the smart meter record energy generation if a solar panel is installed?
All smart meters will record the export and import separately, and you will be able to see the readings by stepping through them on the meter display. All the meters should show all 4 power quadrants. You can ignore the reactive ones and just look at active import and export.

Power quadrants:
  • Active energy import (Wh) - this is what we are billed for normally
  • Reactive energy import (varh)
  • Active energy export (Wh) - this is your useful export power
  • Reactive energy export (varh).
The bad news is that many companies have not set up their systems to automatically collect or use the export information, as it would have taken time and money they don't have for such a low volume user base. (Updated: 2018-10-02)

What is dithering?
When a Smart Meter loses power and powers up it sends an alert message to suppliers and network operators to let them know. If a large area had lost power and thus a large number of meters were to send these messages at once it would put a heavy load on the communications network. To prevent this the meters "dither", that is to say they all wait a short random period before sending those first messages thus avoiding the simultaneous peak. For the first two years (to September 2018) the dithering period was up to 2 minutes. After that a decision will be made on whether to set it to the default 5 minutes. (Updated: 2016-02-16)

How often will my IHD be updated with data from my meters?
Your IHD (In Home Display) will be updated by your electricity meter about every 10 seconds and by your gas meter about every 30 minutes. The gas meter updates less often in order to preserve its battery life which in normal use is expected to be at least 10-15 years. (Updated: 2020-10-23)

My supplier says my signal is too weak?
Smart meters communicate through mobile communications and so the signal strength is an important factor to consider for installation.
For SMETS1 meters the installer will usually test on site and make a decision there and then whether to install. If there is not a sufficient signal they will usually walk away.
For SMETS2 there are more options. The communications are provided by the Data Communications Company (DCC) and suppliers can check that a premises has communications before visiting a site. Once on site they can check with a signal checking device if the signal is strong enough in the meter location. If it isn’t they can fit a number of different aerials to try to boost the signal. If that doesn’t work an external aerial or an alternative mesh communications method is available in some areas. Even then they can leave the meter de-commissioned and ask the DCC to get the communications working. (Updated: 2017-02-01)

Can I fit an aerial?
You cannot fit an aerial yourself. All Comms Hubs and Aerials for Smart Meters have to be supplied via approved channels and can only be installed by authorised engineers. In fact attempting to install one yourself will trigger the tamper alarm on the meter which could mean a chargeable visit from your supplier. (Updated: 2021-11-16)

Are the meters battery powered?
The electricity meter is mains powered but the gas meter is battery powered. The gas meter battery can be replaced by a Smart Meter Installer and is excepted to last the life of the meter (10 to 15 years), however, its life can be greatly reduced heavy communications such as repeated firmware updates. (Updated: 2016-01-27)

What is a SMETS1 meter?
Over 7 million electricity meters and a similar number of gas meters built to the first Smart Metering Equipment Technical Specification (SMETS) 1 have now been installed. These meters are better than ADM meters (Advanced Domestic Meters) but not as good as SMETS2 meters. Each supplier uses them through a different support and communications network; this means they have different functionality and effectively limits the customer from moving from one supplier to another with the same smart meter. For this reason customers often lose smart functionality when changing suppliers. Meters to the SMETS2 standard do not have this restriction as they share a common communication process. (Updated: 2018-05-05)

Do smart meters work with home generated renewable energy?
Traditional meters are only capable of recording consumption and consequently don't take into account any energy generated by a household. If you have or are planning to install solar panels or any other renewable energy generating system in your home, a smart meter will enable you to measure how much energy you produce. The smart meter will also calculate whether or not there is a surplus which you could sell back to the grid.
However, as this is not a common requirement suppliers have been slow in implementing systems to support it - you will have to shop around for the supplier which can support your requirements. (Updated: 2019-10-21)

Close Close Phone Pinterest Whatsapp Email Instagram Twitter Cookie Tick Form Facebook Top
 Back to Top

Smartme uses cookies

We use cookies to enhance your experience, for analytics and to show you offers tailored to your interests on our site and third party sites. We may share your information with our advertising and analytic partners. Find out more about cookies by reading our Privacy Policy, which contains further information about the cookies and other technologies we use and information about how to disable them. Please select the cookies you are happy to allow below.