@rachelmcc Your display device gets its data from the smart meters, it is not your bill, only a rough guide to what you use. With E7 systems the reporting can be confused and delayed, your night usage is almost certainly the water heater. Don't worry looking for details from the IHD device, they often go wrong and yours will probably lose contact soon and say Waiting for data. That is quite normal. You can turn off the IHD if it bothers you, it takes no part in sending readings to SP. Usually the IHD will tell you when heating devices are turned on, but we all know when that happens and you can switch off the fire/kettle/drier/washing machine or whatever is using power.
@rachelmcc The app will start working soon. The point of smart meters is to send readings to SP every half hour. This enables the cost of units to be increased or reduced at different times of the day. This feature has only been turned on by a few suppliers, SP are quite poor at computer technology. In the future we will all get used to expensive power at 5pm, but cheap power at night and weekends. It is government's idea to even out the peaks in demand and take full advantage of wind power. A side benefit of smart meters is to give you a hand held IHD to warn you when you are using a lot of units, the actual costs displayed are often wrong and your bill is worked out at head office and has nothing to do with what the IHD says.
@rachelmcc Not exactly, your meters are most probably sending their readings but the app which reports on them has not yet been set up for your account. Recently the app was withdrawn from service because it was displaying wrong data for some accounts. I suppose SP are working on the upgrade. You could check that SP are getting your smart readings by asking customer services if they can see the readings on their screens.
@rachelmcc By the way when the app starts working again, it will not update half hourly, usually it refreshes overnight and changes once a day so it gives an overview of energy not real-time monitoring.
@rachelmcc Probably your IHD has been set up with the tariff values reversed, it's doubtful SP would sell anyone daytime electricity at 5p when the typical cost is 30p. Again, your IHD is not your bill and they often have wrong tariffs programmed into them.