Why is there a constant 50p display showing on my IHD?

Actually, this is an In Home Displays Limited SmartView 2 which basically means it’s a terrible IHD from the absolute worst possible IHD manufacturer under the sun. It’s unfortunately not worth trying to diagnose and fix ANY IHDL SmartView device (trust me, I’ve tried before!), they’re too unreliable and cause too many problems to be worthy of fixing. There is also no way of turning them off without draining the battery. This is by design for some stupid reason that makes absolutely no sense.

OVO has never given those out because OVO went for Secure Pipit 500 in the SMETS1 days before switching to Chameleon later on in S1 and currently issues a mixture of Geo and Chameleon devices. the closest OVO has ever come to issuing any IHDL stuff was when SSE gave out an SSE branded IHDL SmartView 1 back in the SMETS1 days - but this stopped prior to OVO taking over. AFAIK SSE drained their remaining stocks of them at the same time as getting rid of their final S1 meters around 2018.

Ironically enough, the SSE branded SV1 units DID have an easy to access power off menu that held Power Off, Restart and Cancel options - and all three of them actually did exactly what they said on the tin - and a rechargeable battery that could be removed easily by sliding off the back cover and pulling the battery out. However, for the SV2 onwards, for some boneheaded reason that menu has basically been removed completely, or at very least reduced to just Restart and Cancel in some cases (the former is far more likely though).

The best way - and arguably only way - to fix an IHDL SmartView device is to basically smash it up with a sledgehammer and then send it away for recycling. We do have a guide here on the Forum which can tell you about replacements that may work better:

If you can show us photos of the meter on the wall though, we’ll be happy to try and help you run a few checks that may prevent a bad experience with whichever IHD you get next.