How can I check if my SMETS2 Aclara meter is having communication issues?

  • 12 November 2021
  • 2 replies
How can I check if my SMETS2 Aclara meter is having communication issues?
Userlevel 4

The SMETS2 Aclara Smart Meter Health Check



If your top ups aren’t reaching your meter, or your balance doesn’t always update every day, there may be a communication issue. Here’s a smart meter health check you can do to diagnose this!


Please note that if the meter screen is completely blank and the meter is not responding to actions on the keypad reach out to our Support team to book in a meter exchange. 


1. Are the Meter Serial Numbers (MSNs) correct?


We first need to make sure that the meter(s) we are dealing with are correct (mistakes can sometimes be made, meaning the wrong MSN is listed on an account). 

Where can I find the serial number on a smart meter?

Electricity: The MSN for an S2 electricity smart meter can be found near the meters barcode above the display. The Aclara version of the SMETS2 will start with either 17M, 18M, 19M and next year 20M. 

Gas: The MSN for a gas smart meter can be found below the display. It will start with G4F. 


Let us know these MSNs when you contact the Support team, so they can check that it matches what’s on your account. 

2. Are the meters commissioned?

On the electricity smart meter communications hub (at the top) if the HAN light is not flashing, this would indicate that it has not been commissioned. Further to this, on the screen itself, a commissioned meter would have a signal bar and "HAN" written on it to indicate connection.

Our Support team can also do some checks for this. Proceed to the next steps.

3. Is there a Wide-Area Network (WAN) connection?

These are the lights on the communications hub for SMETS2 which you can find attached to the top of your electricity meter:


Lights on the communications hub

SW - Represents the status of the comms hub's software
WAN - The comms hubs ability to communicate with us
MESH - Communication through another S2 comms hub (will be more applicable when there are more S2 smart meters)
HAN - Communication of elec meter, gas meter, and IHD with the comms hub
GAS - Gas meter HAN connectivity
What lights are flashing and how often? - Please note that this is very different to SMETS1

Low - every 5 seconds - everything is fine here
Medium - every 3 seconds - searching for connectivity  
High - every 1 second -  connectivity issue
Off - connectivity issue

Please check your electricity meter and confirm what the LED light labelled 'WAN' is doing. The lights are on the communication hub (shown in the picture below), which is above the electricity meter.

If the lights are not flashing every five seconds, this indicates an issue for our Support team to be advised about. 

Here are a list of questions you may be asked, if your meter has no or poor WAN:


  • How strong is the mobile phone signal next to your meter?
  • Is there anything metallic in the way of the meter which could be moved?
  • If the meter has something metallic blocking the signal - for instance a mirror or an ironing board - then moving this may solve the problem.
  • Is your electricity meter in a metal box (e.g a metal meter cupboard)? 
  • Is your electricity meter in a basement, or is it partially enclosed (e.g in a closed cupboard under the stairs)?


4. Is there a Home-Area Network (HAN) connection?

The best way to check for the HAN symbol on either meter or on your In-Home Display (IHD):


If any of these symbols are missing then it indicates they are not connected to the HAN. 

In addition, on the comms hub, the HAN or GAS light may be flashing every second or not at all if there is an issue with the HAN. A medium flashing HAN light on the comms hub (5 flashes, pause and repeat) indicates a HAN set up and connected with devices. 

5. Is the meter clocking usage?

Aclara (Flonidan for gas)

  • Electricity: There’s 2 buttons on an electricity meter. Pressing B will cycle through all the menus on the meter screen and pressing A will cycle through all the sub menus. To take an electricity reading, you will need to press A - TOU rate 1 will be the electricity reading. For economy 7 members, TOU rate 2 will show the rate 2 reading.
  • Gas: Gas meters have A, B and C. Pressing C will give you the menu and A & B will allow you to scroll through the options. The balance section is where you can check the reading (when you wake up the meter it should automatically default to the reading screen). Screen 1 - readings, active tariff price, standing charge, export reads, meter mode.


If you’re having trouble making these checks yourself, not to worry our Support Team will be able to talk you through these steps too. The easiest way to reach the team is via our Webchat which you can find by clicking the yellow speech bubble on our Homepage.


Got a Secure SMETS1 smart meter? See our guide here:



Got more questions? - Comment below and we’ll offer advice where we can. :slight_smile:

2 replies

Good evening, We have one of these smart meters for our electricity supply. it’s stopped communicating. I’m trying to book an engineer to come out to see it. I’ve sent various messages on Facebook and web chat, been on hold for over twenty minutes on the phone more than once. There is nothing on the display, a red light flashing on and off the green lights flash every four seconds. Can anyone help me book someone to come out and see it or exchange it please 

Userlevel 4

Sorry to hear that your meter is having some communication difficulties, @SheilaJ.


Sounds like you’ve already carried out the checks mentioned above. The next step would be to get in touch with the Support Team, who are able to pass these on to our smart metering team or arrange an engineer’s visit if needed.


The quickest way to reach the team is often via our webchat which you can find here.


Hope this helps.