[Kodak]

Was an nPower customer on Super Tariff complex meter (E7 rate day/night, plus standard rate Night storage & afternoon boost).

Meter failed & was put onto two times switched meters (one E7 rate for day/night supply, one standard rate for night storage heaters & afternoon boost).


Discovered by chance in Jan 2025 that eON.Next intend to switch my meters by March & turn off the RTS signal so that neither of my supply meters will work correctly.


The replacement options are a standard smart meter or an E7 smart meter.


If I go standard, my night storage heaters become useless. Replacing them & redecorating after the changes could cost £4k.


If I go E7, I lose the afternoon boost and so the house will be too cold from 7pm onwards, necessitating more stand alone heating & more cost.


I can't switch suppliers due to complex metering, either...& no one offers E10 anymore.


Someone at eON.Next call centre suggested going E7, but adding a timer of my own on my side of the supply so I could add my own manual boost to my night storage heaters, but I don't see how that works as the heater circuit will be unpowered outside of the overnight E7 period.


To complicate things, my water heating is connected to the standard supply, not E7, and has it's own timer to control it.


If I switch to an E7 meter, the water heater will be on the wrong circuit.


To say the configuration is complex is an understatement, but it works.


Sadly, it won't work after the changes eON.Next are about to make and it won't be simple to correct.


Getting any advice is proving impossible.


So if anyone on here can help, I'd be very grateful.

[retrotecchie]

@Kodak

Switch to E7. You'll need an electrician to rewire your storage heaters, but that's your responsibility rather than the supplier. A timer similar to what you have on the water heater is not a big problem and will still allow you to boost the heaters during the day, but you'll be paying peak rate for the privilege..

Complex systems went out in the mid 90s along with the Magnox power stations. They were only really implemented by regional boards that had access to cheap baseline energy generated by Magnox, so really only Scottish Electricity Board and Southern Electricity Board areas. No thought was given to modernising such legacy systems when the energy industry was denationalised.. This is why we have the energy supplier SSE...a merger between Scottish and Southern makes no sense if it wasn't for those two regions using complex systems.

Anyway, the current setup doesn't support these 30 year out of date systems, so it's E7 or nothing really. Simple enough to remedy by any competent electrician, but it's down to you, not the supplier.

A five terminal meter will give you just the separate timed feed for the water otter and the heating, but if you want boost, you are better off with a regular 4 terminal non-switching meter and a more up to date timing system.

I've done enough of these conversions myself, so they ain't rocket science, but anything forward of the meter is the responsibility of the consumer, not the supplier so they aren't likely to offer any assistance with the conversion.

[Kodak]

@retrotecchie So if I switch to plain E7 and add my own time switch, rather than have the heaters wired to their own timed on/off circuit on the meter, I can retain the boost?

The switch I have at the minute is a Horstmann, but they don't seem to do an equivalent switch that would handle a bunch of night storage heaters all coming on at the same time.

Is there a device you could recommend? I'm at a complete loss at the moment and, so far, electricians I've asked don't seem keen to take to work. I got the impression it's the E7 and timer bits they don't like.

[retrotecchie]

@Kodak

Here's how I would do it:

Get an electrician to wire the existing storage heater feeds into the existing normal consumer unit. Obviously using a suitably rated circuit breaker. That is to say, the storage heater feeds are permanently live.

Replace each of the faceplates for the storage heaters with a switched 13A socket.

Rewire the storage heaters with a standard 13A plug on the cables.

Use a suitably rated plug in timer on each heater. Set the timers to operate when the off-peak rate is in effect. Use a decent timer rated for the full 13A, not a 'Mickey Mouse' one only rated for switching the Christmas tree lights or a table lamp!

If you need a boost, use the override switch on any individual heater timer to give you the extra heat you need. Just remember to set it back to Auto when you're done. Of course, with a modern timer, you can set individual boost periods as required. You will, of course, be paying daytime rates for that boost outside of the usual E7 times.

If you already have a separate breaker/fuse box for the storage heaters, that just needs to be fed in parallel with the existing consumer unit from the single meter - that is something a meter engineer can do.

[Kodak]

@retrotecchie
Thanks for that.

Heaters are currently hardwired, each through its own fused switch. Is it safe to switch them to a regular 13 amp fuse as they're never sold that way.

I vaguely recall being told to hardwire them as they draw a higher, forgive my ignorance on this, current (?) than regular heaters.

[retrotecchie]

@Kodak

I don't think I've ever met a storage heater bigger than 3kW which is safely inside the limit of a 13A plug. The usual reason for hardwiring is so they only use dedicated heating citcuits driven by RTS or E7. It also prevents people plugging in other appliances to benefit from the cheap off-peak electricity on the complex heating schemes.

If the heater draws more than 3.25 kW, dedicated hard-wired timers can be used. Even B&Q sell higher power hard-wired timers that can be used for immersion heaters or storage heaters.