@Betteridgesr welcome to the OVO Forum! I hope you’re well, and thanks for your post.
Hold off buying an IHD!
Just to confirm, we do currently have stock of IHDs for enrolled S1 meters. Enrolled means that the meters have gone through the ‘enrolment and adoption’ process, whereby old S1 meters like yours are remotely upgraded so that they communicate with all suppliers. If you’re on supply with us, and your smart meters are sending us reads, then they’re enrolled.
Contact our Support Team and request a new IHD, they should have one sent to you within the next ten working days, free of charge. You’ll need to contact Support again when the IHD arrives - they’ll help you pair it to the smart meter.
When your new IHD arrives this guide should help you get set up: