Howdy ​@GrumpyTrucker , welcome back! :)

Definitely sounds like a frozen Comms Hub to me. It might fix itself, but I’d still suggest flagging it via https://smart-meter-help.ovoenergy.com for now, even if just to see what the tool says about it.

Let me know what it tells you!

Hey ​@Blastoise186 good to hear from you. Yeah, I've been woefully absent. I hang my head in shame. Work hours changed and they just get in the way more now than they did. I did try swearing at the IHDs just in case, but that didn't work either.

The smart meter tool just says my meters are sending readings so go away. Well, not that exactly but it won't let me go further than confirming meter numbers. Really hoping it's just the cold that's done for it and it comes back soon. Kinda pointless having a smart meter without smart information to go with it

Gotcha. In that case, have a word with Chameleon about the ivie as they might be able to diagnose the issue. That’ll prove useful for me to suggest options

It might not help on this but both the ivie and the Chameleon (IHD3) can get stuck when rebooting. 
You might have already tried but it’s worth removing power from both devices for several minutes and then reconnecting. It’s possible that they’ve become disconnected in an unusual state and need internal levels to be allowed to revert to a standard off state

Unplugged them for half hour or so but sadly both are still the same after plugging back in. Hopefully it'll sort itself out. If not, it's onto OVO again. I don't know if the communication hub can be replaced without the whole meter, but it does seem odd that the WAN is working and it's just the HAN that's "dead". 

The Comms Hub is always hot-swappable on SMETS2 without replacing any other component - the designers considered that possibility!

This little tool might reveal something wrong: homebrew.n3rgy.com. Put in your MPAN and tick the tiny confirmation box before clicking Check meter. Don’t worry about any warnings about certificate expiry - they don’t matter. You’re looking particularly for warnings or errors in respect of the In-Home Display.

Just a quick update before work. Looked at the meter this morning and both the WAN and HAN lights are blinking green in unison roughly every 5 seconds which if memory serves is normal? 

That’s correct

A little aide memoire (if the link works ) : Technical information on UK SMETS 2 Smart Meters
 

No errors on anything, just a warning that the security certificate on the Electric meter will expire soon.

IHDs are still not connecting. Ah well, guess it's the minefield of OVO support soon at this rate.

Wouldn't be so bad if the OVO site at least gave a daily cost in the cost column on the usage page, but that seems too difficult for them.

OK, thanks. 
  

Odd. I thought he tool queried the IHD (e.g. to get its GUID), but perhaps it only checks what information the CH has stored for it. Anyway, if there was a problem with connecting to the IHD, the tool would say so and even give a reason. That’s apparently not the case here.

Have you checked for interference? All sorts of stuff may be using the same band as the HAN: in-house devices connected to wifi, baby alarms, garage door openers, smart fridges and so on. The IHD will usually look for the best (least busy) channel to operate on, but may not find it. To test, disconnect anything (including the wifi router) that might be using the 2.4 GHz band, then try rebooting the IHD again (unplug, remove batteries, wait a few minutes, then re-insert batteries and plug in again).

What devices did you find? Any joy? 

It does - view it via Monthly view and you get the Daily costs.

Hi ​@GrumpyTrucker 

Sorry to hear you’re still having issues with your IHDs.

Unfortunately, as we don’t have access to accounts here at the Forum, you’ll need to get in touch with the Support Team so they can run a few things remotely.

Keep us updated with how you get on.