Really need some serious help with Electric unit use/bill cost (thank you)

First thing to do before anything else is to check is either the opening reading or the closing one on the bill estimated.

I notice no mention of cooking - do you use an electric cooker a lot? Also, kettle? How is shower heated - is it a straight electric shower or are you using an immersion heater to heat a whole tank? I know you said you have a water boiler but not clear exactly how big it is. How do you dry clothes? Tumble dryer?

Basically, anything the produces heat is a big electricity user so those are the things to look at most intently.

mrs bop had a problem like this with her apartment. check the meter number on your bill against your actual meter.

mrs bop was being billed for the apartment above her and they got her bill.

I do 24 hr reading so I read it every morning at 10 (alarm in phone), very quickly you will notice daily increases which could be shower/washing machine etc so I make a note of them on my wall planner with the reading :) Once you know what your base rate or as I call it the house tickover rate is then it's easier to identify extras like the heating.

I have a radon fan and was convinced it was using a lot of power so one day when I was going to be out of the house for most of the day I turned off everything and I mean everything freezer/fridge/clock/radio etc, all standby switches for cooker/oven etc switched off, nothing was on but that blasted radon fan. Noted the time I left the house and when I got back took reading and was then able to work out the exact kw usage of that fan and extend it out to what the daily cost is as it runs 24/7. Turns out it wasn't the huge cost I thought it was but at present rates it's adding the bones of €18 to each bi monthly bill so enough to be obvious!

You could do it as you say if you have the time to dedicate to it but a couple of hours can be hard to pinpoint in watts with small usage items if you have the fraction bits on the meter, impossible I believe with the new smart meter as I think it only clicks over a full unit each time so you don't see the fractional use.

Not an expert but you say water heater on at 2am....when does that switch off...you might be better off with immersion on for an hour just before you get up...also electric heating is always way way more expensive than oil....

What was your bill/energy usage for the 2 months before this period when the heaters were used everyday (i assume)?

This is either a case of your previous bills being estimated and this is a "catch up" bill OR something is faulty.

For reference, i live in a 3 bed semi with another single guy and our usage is FAR lower. We do have gas heating but still.

Does signing up for this change the mcc of the meter?

No. This service exists so you can get the info off a smart meter that is still on a 24h MCC.

It takes weeks for them to start giving you the data, though.

What? I thought the general idea is that we all switch towards electric heating, heat pumps and so on. And away from oil.

To OP, possible someone else is using your electricity and you're paying for it. Big users in your case sound like the electric heaters and water heating/ immersion. I'd be checking them first.

It provides usage information in half hour slots. It doesn't impact your billing at all.

Oil is still cheaper for heating but electricity can be better for the environment depending on how the electricity is generated.

The idea is to move to heat pumps in new build that have exceptionally good insulation(energy ratings), when built to spec and used correctly heat pumps should not be expensive.