Ok, after thinking about this for a couple of hours and chatting with my friend Blastoise186 about it, I think one of the diagnostic tricks in my toolkit is probably worth a try. I'm not usually one to copy/paste, but when it comes to how to pull off a Creep Test, it's the easiest way to make sure I get it right. The idea of this test is to try to identify a possible meter fault where it continues to clock usage even when you've totally turned off all the power to your flat and the meter should have stopped.
Before you get started, I strongly recommend only doing this test during daylight hours for your own safety and you may want to have a torch handy just in case. Please also make sure to safely shut down and turn off any sensitive electronics and gadgets like your computers, TVs, games consoles, Wi-Fi Router, Smart Home gadgets and anything else that might be affected by having the power suddenly go off. You can leave the fridge/freezer on though and keeping a couple of lights on is helpful so that you know when you're done.
If you're happy to go ahead, here's what to do. These steps might sound a bit tricky as I generally copy/paste them directly from what Blastoise186 gave me, but they should work.
- Locate the electric meter and fuse box/consumer unit
- Take a quick meter reading and note it down - you'll need it later
- As you're on Prepayment, please make sure you've got some credit and you're not in Emergency Credit - otherwise it can disrupt the test. If you don't have much left, now is a good time to top-up!
- Turn off the power to the entire house using your consumer unit - it'll only be for a few minutes so don't worry about being off-supply for a long time
- Observe your electric meter for about five minutes. the red metrology LED (or the spinning disc in older meters) should stop completely and the meter should not clock any usage after the first 30 seconds or so
- After five minutes, take another meter reading and note it down
- Turn the power back on
- Compare the two readings you took at the start and finish of the test
If the meter is not faulty, the two readings should be about the same. However, if they're massively different and/or you noticed the metrology LED (or spinning disc) continue to run and/or the meter was still clocking usage despite the power being off, then there's almost certainly a fault with the meter itself. In this case, you'll want to request a Meter Accuracy Test. It'll cost around £160 upfront and you'll get this back if the meter is confirmed to be faulty, as well as having the meter replaced and a refund issued for the lost credit once E.On has managed to figure out how much it's thrown into a black hole. Please bear in mind that the test fee is not refunded if the meter is found to be working correctly. With that being said, if it failed the Creep Test then that's already a very good sign that the meter probably is faulty - the MAT is still required to make it official but doing the Creep Test first might save you wasting £160.
I also suspect that the fire you had in your flat may have caused further damage elsewhere that might not have been spotted during the original repairs. Please could you post some photos of the meter(s) and everything around it in your next reply, as I'd like to quickly see if there's any meter damage I can spot with a quick visual check. A local electrician should also be able to help with further diagnostics in your flat, such as tracing wiring and potentially identifying any power guzzling appliances that are taking up more than their fair share of your supply.
Meter or supply tampering is also a possibility that I wouldn't rule out at this stage and it's not impossible that someone else has illegally tapped into your own supply without your knowledge. I think an electrician might be able to help you check, but I'd also recommend flagging this up with customer service if you suspect possible energy theft. You won't get in trouble for submitting such a report, even if turns out to be a false alarm. Normally, I'd be able to provide further info on this process, but I can't seem to find it for E.On for some reason. I'll chat with Beki and Hannah about that later today.
The only other thing I can think of, is whether you're just using more power than you thought you were, or your tariff is more expensive than expected. This isn't something I'd consider as an excuse to dismiss all the other possibilities though.
