Hi @MikeDickson , it’s possibly a battery alarm to say that the battery needs changing. You will need to get customer support to organise a faulty meter exchange. 
There’s a similar thread here (although with a different remedy) 

Hey @MikeDickson 

A beeping meter could indicate a number if things including the battery beginning to fail along with a whole host of other things.

As a battery failure could affect your supply, reach out to our Support team as soon as you can to confirm this is the issue and book in a free meter exchange. All gas meters have a battery installed so this is an issue which can affect smart meters and traditional meters, although as the battery is designed to outlast your meter certification date it’s rare for the battery to fail before you’d be due a meter replacement anyway.

See more on these helpful topics below on noisy meters:

Have a check and ensure the beeping is coming from the meter itself and if so get in touch with the Support Team. They may request a video so it’s always worth taking one just in case.

Let us know how you get on with this, as it could be very helpful for other community members in the future.