Economy 7 - need confusion clearing up please!

snowhead said:

The black unit in the middle is the time switch that enables the Off Peak fuse board for the heaters and water.
It's switched at the times shown, E.7, or should be, by a Radio signal put out on BBC transmitters.
They were originally mechanical timeswitches but changed to this unit, then to timeswitches built into the meter.
The radio signal is being turned off sometime next year so that's probably why you're going to a "Smart Meter".

If the off peak water heater is coming on then the off peak heaters , if switched on must be.

Bristol Energy or their subcontract meter fitters / meter leasing company should be removing the black teleswitch and using a 5 wire "Smart Meter" that will also do the switching for Off Peak.

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Hello snowhead,

Just want to report back that after 4 weeks of hassle we've managed to go from a traditional meter to a "smart" meter.

Indeed the black teleswitch has been replaced by a 5-wire meter.

Interestingly enough, this has not fixed our original problem; that OFF peak circuit is still on during daytime under a E7 tariff.

The installer was quick enough to show us that the 5th cable is constantly live (the one on the right.) Hence no time switching happens.

How does this happen? Any idea who we should speak to?

Unfortunately, you will now have to install your own time switches for the devices you only want powered during the off peak times.

Richard Burns said:

Yes, during non E7 hours the top left board should be off and all power consumed by the lower right board will be at normal day rate.
When E7 hours start the top left board will be powered up and anything connected to it will start (if switched on). The meter will then be recording the power consumed by both boards on E7 night rate.

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Good afternoon, I'm must first apologise if this has been covered elsewhere, but i cant seem to find an easy answer.

Easy question is - are there any Smart Meters capable of switching an E7 circuit in and out without a separate timer? I do have a two tariff contract (E7) and I am concerned I am using power for storage heaters and immersions etc on full price tariff.

Background - I had an almost identical set up to the one on the picture above, one meter capable of switching in a separate consumer unit with all of the E7 heaters and immersions for the 7 hour period (12:30 - 07:30). This worked fine for years, infact from the time the house was built in the early 1980s. A while ago (~3+years ago) EDF fitted a smart meter, I took very little notice until one day in the Covid lock down I could hear my immersion heater on in the middle of the afternoon, I checked and it was the E7 circuit that was powered. I monitored this for a few days and could see that the storage heaters main feed was also live at the same time. It did seem to switch on and off but the time seems to vary.


(both in day time)

I contacted EDF but i cant get a simple answer. looking at my wiring I am unsure if my smart meter has the ability to switch in a timed circuit or if i should have been told to get a timed breaker added?

This is my set up is as below with Red/Black feeding the 24/7 consumer unit (13A ring main, Lights, cooker, shower, etc) and the two grey wires supplying E7 only (timed?) circuit (HHR Storage heater main feed and immersions) -


I still have no idea about live connection from bottom of smart meter
Thanks in advance

Richard Burns said:

The separate board easily allows the items powered during E7 times to be on only during those times. The whole board is switched (probably in your case by the meter). If you have just one board then each piece of equipment for E7 would need to have its own timer.
Some arrangements do mean only the E7 items are charged at the E7 rate and the main board at normal rate but your description does not sound like that (it is fairly old school now).
You probably have something like the below diagram
View attachment 48732

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Richard (love your diagrams). My 'electrician' friend (a DIY-er), said he could help me with a problem but I would like your initial thoughts on it after seeing this diagram of yours. (Well it sounds like you know what you're talking about so it makes sense to ask!). I used to be on economy 7 but now I am on a single tariff as it suits me better. But I still have a 2 rate meter and my second fuse box (white box) still only comes on at night. But this is a waste as I want to use the circuits from that 'E7 Consumer unit' all day and night long - as I am on a single all day tariff now. So his thoughts are to put both fuse boxes on the first tail which doesn't have a timer and which would provide electricity to both fuse boxes all day long. I've uploaded an edited version of your first diagram to hopefully explain what I trying to say. Do you see any problems with this? Much obliged.