I came across this thread while trying to figure out what's wrong with my smart meter and IHD. I'm currently with Sainsbury energy (white label reseller of Eon Next) and am billed by Eon Next.
My smart meter(s) were originally installed by British Gas and look exactly like the those in the pictures posted by @GardenerMart
I have the flashing HAN light problem and no Gas display on the IHD. I also have to submit meter readings online to Sainsburys energy as they can't read the meter remotely and, if I'm honest, I'm a bit worried that the electricity meter might have an accuracy issue as my annual energy consumption appears to be almost three times what's typical for my type of house.
Is there any chance I could also get my meters upgraded as, I assume, it could resolve the service issue and confirm or refute if there's an accuracy issue at the same time.
Thanks,
Con