Faulty traditional meter

https://www.ovoenergy.com/help/article/electric-heating/other-two-meter-tariffs

we don’t have electric storage heaters, but we are thinking of putting some into the attached rental cottage as it’s currently not heated, so this would mean they need attached to the same meter as the water/oil fired hesting? Thanks 

Yes I was thinking some legacy from a commercial set up, which probably isn't suitable for domestic usage paterns

Storage Heaters aren’t the golden bullet that they once were - use caution as there may be better options. We’ve got members here who can help with that advice better than I can.

But yes, they would definitely have to be on the off-peak rate. You don’t want them on peak! Trust me on that one!!!

Hot water/heating, normal electric, Franken-Lever

No idea, but includes: oil fired boiler, water tank, back up long arm tick thing, back up electric immersion (never turn on or it costs £600!) We currently use wet radiators fired by oil, the cottage has no heating but we thought we might install clay core rads or storage heaters…which by the sound of it I should get wired into the THTC meter…except that is going to break in a year because of stopping something or other or is that just the main/broken meter? 
so confused! Thanks for all your advice guys.

The oil DHW\CH will be cheaper than storage heaters so I wouldn't swap. With what you have you really don't need any form of off peak rate. Bit check your bills and do the maths or post on here what tarrif and rates you're in and what consumption you have

The appended rental cottage isn’t on the oil CH just the main house where we live, cottage wasn’t  heated at all so we have installed a wood burner, an electric towel rad in bathroom, and we have 3 clay core electric heaters to fit in the 2 bedrooms. my bills are indecipherable but I’ll try to work it out. Thanks 

Thanks, for reasons I don’t understand all the readings have ‘estimate’ beside them but we gave meter readings most months, bit odd! 

Here’s a photo of a month, we’re obviously overpaying on our per unit rate eh?

I’m really unsure what to do for the best since in OUR house our usage will stay the same so we should shop around, swap, get smart meter etc, but from the Autumn we will have paying guests in the appended cottage, and they will use hot water daily (currently on the THTC) and we can either install clay core or some other storage heaters for them (I assume these can go on this meter too) so the usage in there will quite dramatically increase…

Any advice on this whole issue most appreciated!

You’re welcome - keep posting and we’ll try to give the best advice we can between us. That’s one of the things this forum is amazing at - and all the advice we offer is free too, which is a bonus!

There’s two possible meter setups that you could be on. I very much doubt you’re on Standard Economy & Heating Load because that tariff is absolutely useless 99% of the time if you’re on oil heating. I also can’t see you being on Economy 7/White Meter based on what you’ve said. The only other one would be THTC and that’s what I think you’ve probably got.

When it comes to THTC stuff, I have a direct contact at OVO who’s been helping me out and keeping me informed. I can’t tell you his exact name, but it rhymes with Bim so you can probably figure it out. :D

The latest info I have from “Bim” is that THTC Support for Smart Meters is still in development with OVO’s teams. It’s coming soon though! Please wait and I’ll try to get a refresh because that info is a few months old now.

Hi @zedzedhoney, it’s good actually that the supply for the attached cottage is in your main home, much easier to manage than having a separate meter in the cottage: there is absolutely nothing against you installing your own meters “downstream” of the house meter, on the cottage circuits before they leave your doom room. One meter for heating/hot water circuits, one meter for everything else in the cottage. And I’m guessing guests will have their energy included and won’t be billed separately for energy?

I have two such meters in our own smallish terraced house: one cheap meter for the conservatory because I installed underfloor heating there, before we swiftly installed a log burner the following winter (underfloor heating outrageously expensive to run, slow to warm up, doesn’t really retain heat, while the log burner, a relatively tiny Hamlet, smaller than our living room Morso, is fantastic). And 20 years ago I installed a whole-house Elster 100 Amp meter (other brands are available!) just downstream of the main meter in the cupboard which acted as a very useful check on the supply meter before we went smart…I still check the readings every night, though, both for import and export, and it’s still pretty accurate for my non-billing purposes. 
 

I guess you wouldn’t need to instal a separate meter for oil, though? Presumably there would be a reasonably constant relationship between every kWh of electricity used for heating or hot water and the amount of oil consumed by the boiler? It wouldn’t be an absolute constant of course, allowing for time taken to heat from cold for example, but there would be a reasonably discernible relationship over time I’m sure. 
 

There will be advice from others here on best ways to heat holiday lets/second homes/granny flats etc. and I’m guessing that by electing for clay core radiators or storage heaters you are aiming to provide all-round comfort for guests without their having to fiddle too much with things, or you worrying about their leaving the place all day with a door or window open with some thermostat demanding heat? But nevertheless a simple room thermostat with a maximum of, say, 20 degrees could work just as well? People might well want to adjust things for themselves anyway, especially at night or first thing in the morning.
 

Sounds like you’ve got some good plans in place anyway, and now is a good time to get the metering sorted in plenty of time for August.  But definitely think about getting advice for upgrading RDC/RCBO provision for those cottage circuits well before any guests arrive!