I’ve just come here from the MSE forum having been told that the meter system for an aberdeenshire council rented property I will be moving into soon is THTC.
This huge bundle of cables and boxes is truly terrifying to me. I’ve been looking at things regarding economy meters and THTC on the internet tonight and it all means absolutely nothing!
Add to that, the solar panels on the roof and it just becomes an even bigger mess. Apparently Octopus are the current supplier...
So I was wondering if anyone can help me understand this whole system before I move in in a couple of weeks time. Especially regarding how and what gets replaced to convert it to a (hopefully!) simpler smart meter system.
Most importantly, what do I do when I move in?
Thank you in advance.
Officer_Crabtree
Best answer by M.isterW
Updated on 12/09/25 by Emmanuelle_OVO:
Find out more about the RTS shutdown here:
With THTC you have two meters that are charged at different rates. One meter (the more expensive one) is used for lights, cooking, normal sockets etc. That's everything in the consumer unit in your third picture.
The other meter is a cheaper rate and is for the stuff in the other two pictures. The storage heaters should be controlled by a radio switch. This means they should come on and off automatically and the timing is weather dependent. The water heater and panel heaters (it looks like you have three of these) are also on the cheap rate but are available all the time.
You have solar PV but it only feeds the stuff attached to your higher rate meter. It doesn't supply electricity to your heating.
Octopus doesn't support THTC so I've no idea how your system is working. I assume the radio switch is still receiving a signal to switch the storage heaters on and off. Your bill indicates that Octopus have the cheap rate meter on a two rate tariff but they're charging all the use at the lower rate. If you're happy with that and your heating is working I'd probably stick with it. OVO are supposed to be closing down the THTC radio signal next year so the system will have to be changed soon anyway.
It would be good to hear back from @Rosey about this as those times would be useful to preheat the house and hot water, though the heat pump does work most efficiently if left running constantly.
Having read back through this thread and found the link to Scarf: https://www.scarf.org.uk/householder/hes/home-renewables/ I wonder if anyone there can suggest the correct way to set up your heat pump to make best use of the thtc supply ??
The SSE THTC setup required at least 60% of the installed Heating Load to wired to the teleswitched circuit, leaving upto 40% capacity to be available on the 24hr circuit. So heat pump on 24hr (circa 3Kw) would need 4.5 Kw of storage heaters installed (you don’t necessarily have to switch them on…)
Please can someone advise. I moved into our new house which originally had storage heaters but they were replaced with the electric thermal radiators at some point. However, they still seem to run through the THTC meter is this right? We would just turn it on or set a timer rather than it coming on and off at a lower rate.
So really I'm probably as well to leave it the way it is as it would be the cheaper rate? Or will they only work at the certain times (cheaper time eg. Night). I know they are phasing my meters out any way. Ive had storage heaters in my previous houses which made sense to be connected to the THTC but not these ones 🤔
But i use my heating through the day as they are not storage heaters. Will the jyat be on the cheaper rate anyway?
Probably not - you can see your rates on your plan page. Off peak is usually overnight (depends on region). If you need to use the heaters during the day you may need to get a flat rate rather than peak/off peak. Not fully sure how that works with THTC so best check first
