RTS turn off

[SUNRAY]

The funny thing is a friend had what sounded like an urgent sounding phone call to have their E7 meter replaced and it was done on 21-24 July (he says 21st, she says 24th??) Meter fitter has left the RTS in place switching the heaters, however had to move stuff around to make space for the larger meter cocked-up where the Henly block is and linked the feed from the 2nd terminal of the CO rather than the metered lead. Leaving instructions that they need to get an electrician in to reconfigure their heating CU wiring.

I've had my friend confirm over the phone it has been left like this

With written comments that they need to replace the RTS with a timeswitch capable of switching 60A.

The difficulty now it trying to match the cheap rate of the SM to the heating control

 

[Rodders53]

What? There are 5-port smart meters made for this very purpose with 100A main and Aux port Contactors.

How do UK Smart Meters work and who runs them?

How do Smart Meters work? Who is responsible for each part of the system? How does prepayment work? What is a 5 port meter? What is randomised offset?

www.smartme.co.uk

One example being https://www.smartme.co.uk/docs/101819SP01 EM425UK2 5T_EMEA_Web.pdf

Your friend needs to vehemently complain to his supplier and get a suitable smart meter fitted and that RTS unit removed... there should be no need for a contactor (unless a different 5-port meter with a weedy Aux contactor has been fitted... Can you fins out what he has?

NB Reports elsewhere (DigitalSpy) suggest R4 LW audio programming may be going off on 26/09/26... not necessarily the LF RadioData signal, though.

 

[SUNRAY]

What? There are 5-port smart meters made for this very purpose with 100A main and Aux port Contactors.

How do UK Smart Meters work and who runs them?

How do Smart Meters work? Who is responsible for each part of the system? How does prepayment work? What is a 5 port meter? What is randomised offset?

www.smartme.co.uk

One example being https://www.smartme.co.uk/docs/101819SP01 EM425UK2 5T_EMEA_Web.pdf

Your friend needs to vehemently complain to his supplier and get a suitable smart meter fitted and that RTS unit removed... there should be no need for a contactor (unless a different 5-port meter with a weedy Aux contactor has been fitted... Can you fins out what he has?

NB Reports elsewhere (DigitalSpy) suggest R4 LW audio programming may be going off on 26/09/26... not necessarily the LF RadioData signal, though.

That's brilliant, thank you. TBH I couldn't help thinking that should be the case and of course I should have looked myself
The big issue has been the space, the new meter is more than double the size of the old and it is all really crammed in, imagining a meter box on it's side won't be far off.

My main reason for posting this has been the way the offpeak RTS and CU is wired directly off the DNO fuse and not through the meter. I imagine due to the Henley blocks being moved to make space. Unless of course it's always been like it!

 

[ericmark]

Without an isolator, there is very little an electrician could do. I did look at the smart meter which switches the supply, but for me, it would not really help as too much rewiring involved, it is a problem reminding my wife when things can be set off, the move from 00:00–05:00 to 00:30–05:30 when we changed suppliers, does seem to catch her out, in summer no problem there is normally battery left anyway, but most the heavy users washing machine, dishwasher etc, use high power when first turned on, over running at end of off-peak unlikely to cause a problem, except for dishwashers which dry the dishes.

But when already wired to have dedicated off-peak circuits, better to continue that way, so no error as to when items start to run.

What I do question is the huge difference in off-peak tariffs, why should someone charging a car with off-peak pay very much less as to someone heating storage radiators? We are looking at as low as 5p/kWh OP for some EV tariffs, but economy 7 more like 20p/kWh, OP it seems robbing from the poor to give to the rich. Many poor people have storage heaters, only the rich can afford EV cars.

Yes, the peak also shifts, but looking at rate designed for solar panels Octopus Flux and compare with rate offed for non-tied EV users Octopus Go, and the Flux rates do not seem to make sense. the non-tied Go rates are 8.5p/kWh and 30.17p/kWh and export is 15p/kWh as long as the export rate is the same or more than off-peak, one can fully charge batteries overnight, but if export is less than off-peak, then one needs to be careful not to run out of room in the battery to store solar.

First 18 months of solar, I was not paid for export, and the second battery resulted in me loosing money with an off-peak supply, and I was better off with a fixed 24-hour rate.

So now, looking at Economy 7, does it save the user money? And what will be the result if they went to a 24-hour fixed rate? For the user, only heating rooms as required, can dramatically reduce energy used. I found this with oil fired central heating when I fitted 10 programmable TRV heads, so rooms only heated as and when required. So in spite of not getting off-peak, the bills could drop.

However, drawing power during the day when doing other things like having a shower or cooking, could mean using more than the supply is designed for, but I would think unlikely.

But for the supplier, having a dramatic reduction in off-peak use, and an increase in peak use, seems likely to cause them problems, but once people realise they are not paying more having got rid of off-peak, they are not likely to return, had I not started being paid for export, I would have stopped using an off-peak tariff.

The other option is, to swap tariffs summer and winter, and only have off-peak in the winter. Having 1 in every 100 customers swap summer and winter is one thing, but having 50% swapping is another, and likely we would see more leaving charges for changing tariffs. I was rather surprised, I expected when my EV tariff with BG time ended where I needed to pay to exit it, that it would carry on but without exit charge, but no, it reverted to standard single rate tariff, which as it transpired saved me money. Had I not changed to Octopus, I would have not got an off-peak tariff again, it was only when I started being paid for export, that the off-peak made sense again.

So suppliers could very well shoot themselves in the foot if they do not get a smooth transition from teleswitches to smart meters, which is likely going to be good for solar panel owners, as I can see the duck curve in supply getting worse and worse as more solar panels without batteries are fitted, and the export rates offered are likely to fall, but an extra load during peak times as people stop using Economy 7 will likely extend the point where suppliers say thank you, but no, thank you to solar export. I just hope my panels pay for themselves before that happens.

 

[Harry Bloomfield]

What I do question is the huge difference in off-peak tariffs, why should someone charging a car with off-peak pay very much less as to someone heating storage radiators? We are looking at as low as 5p/kWh OP for some EV tariffs, but economy 7 more like 20p/kWh, OP it seems robbing from the poor to give to the rich. Many poor people have storage heaters, only the rich can afford EV cars.

Isn't that a lot to do with EV's being able to use intelligent charging, the supplier being able to control the charge? Whereas charging SH's takes place, with zero control available to suppliers.

 

[AndyPRK]

I think a car is the equivalent of 2 storage heaters
Storage heaters have thermostats (though take several hours to switch off)

I find it interesting that CT clamps are used with EVs, yet no one was fussed when storage heaters were fitted, consuming much more.
Is that just because we have electronics now? or because cars take so long to charge,

I wonder if this intelligent charging is actually being used? or has it just been implemented as a safe guard.

 

[flameport]

I wonder if this intelligent charging is actually being used?

Yes, it's being used by many people.
as of May 2025, 200000 of them for one tariff from one supplier https://octopus.energy/blog/The-growth-of-Intelligent-Octopus/

I find it interesting that CT clamps are used with EVs, yet no one was fussed when storage heaters were fitted, consuming much more.

Buildings with storage heaters would have had their incoming supplies sized appropriately for those heaters, as electric heating would have been there from when it was constructed.
EV charging is a retrofit to existing supplies which were not designed for such loads.

 

[ericmark]

Isn't that a lot to do with EV's being able to use intelligent charging, the supplier being able to control the charge? Whereas charging SH's takes place, with zero control available to suppliers.

With intelligent charging, 5p/kWh off-peak, with user control 8.5p/kWh off-peak, solar 17.1p and Economy 7

Updated 1 July 2025. (1) Energy usage calculated at 3,900kWh/year. Average prices across all regions (average day rate 32.13p/kWh, average night rate 14.06p/kWh, average daily standing charge 51.2p/day).

So they pay more both day rate and night rate to me with "Go" with 8.5 p/kWh and 30.17 p/kWh 66.11p/day their gain is it is got 7 not 5 hours. Average Eco 7= 24.495p/kWh Go = 25.65542p/kWh it seems the rates have changed, but in the main without some battery and inverter in Summer we will use more in the day as to at night, so we still need to use power at the right time. And not lose it due to heating rooms when not required.

​

 

[SUNRAY]

Buildings with storage heaters would have had their incoming supplies sized appropriately for those heaters, as electric heating would have been there from when it was constructed.

Oh dear, the property in question has 6 NSHs and immersion heater on 60A fuse (according to the paperwork left by meter fitter) on a looped supply.
Assuming all are 2.4KW, even the 2 large ones???

None of this has altered since the owner purchased the house new in the late 60's. Wiring shown red and black are the original black 16ishmm² tails, brown and blue are new 25mm², pressumably installed by the meter fitter.

 

[ericmark]

I have only seen one set of houses, designed for storage heating, and it had a central store, and hot air piped to rooms as required, the store would stay hot for a week, if the energy not used, so rooms were heated only as and when required. Built for the local council, I would think mid 70s. All the storage radiators were really an afterthought, and there were some huge errors, where the supply was nowhere near what was needed for the home.

In around 2000 I had a storage radiator in my office, not really to keep me warm, it was to test concrete replacements for the clay bound bricks, in both cases the brick was mainly iron ore, the concrete or clay was only to hold it together as a brick.

It was a failure, as the iron ore changes state one first being heated, which releases water as a result, the whole idea was to use less energy to produce them, but they would still need heating to around 300ºC to release the water, before they could go in a storage heater, and the cost to do that, tipped the balance.

But to conserve energy, and so running costs, we need to only heat rooms as and when required, electric heating, both heat pump and storage heaters, have a problem with that idea, the radiators in a home need to be able to sink around double what the boiler can produce, as we want to heat rooms fast, and in sequence, so if we consider someone returning home from work, likely kitchen and dinning room first, then living room, followed quite a bit later by the bedrooms. This is further messed up, where a bedroom is used as an office or craft room, etc. And some rooms may not be used every day, today we have not been into craft room, office, guest bedroom, guest kitchen, guest bathroom, or guest living room. Clearly today don't need heating, but in winter heating those 6 rooms when not used is silly. But we don't know when a guest may arrive, so need to heat those rooms at a moment's notice. Most electric heating options seem to not allow one to quickly decide you need to heat an extra room. Except for the very simple electric oil filled radiator in every room.

Even with oil central heating, we still have an oil filled radiator for emergency use, also an open fire, the latter has never been lit, I have made an adaptor, so the AC exhausts up the flue. Means I can turn it on before heading home on hot days, without leaving a window open.

But to heat all areas in this house, just in case we want them that day, 14 areas, seems daft, 4 rooms grouped together as guest rooms, the rest have programmable TRV heads, one linked, and three wall thermostats, two motorised valves, two pumps, one boiler, plus an open fire. And the central heating is on an UPS system so will still work with an electric power cut, and with electric central heating of any type, the problem is keeping home warm with a power cut.

So in conclusion, the problem with storage radiators is, one will not work when there is a power outage, and two one has to know in advance when they will be required. Not much one can do about power outages, but as to advance warning, moving to a simple panel heater removes the advance warning problem, so likely one will heat both less of the home, and you will never overheat a room, so likely loss of storage heaters will actually save one money.

 

[Rodders53]

None of this has altered since the owner purchased the house new in the late 60's. Wiring shown red and black are the original black 16ishmm² tails, brown and blue are new 25mm², presumably installed by the meter fitter.

If that is true then he's never paid for heating or E7 hot water since that date. Has he got pics of before and after the smart meter install?

RTS installs often had two separate meters (peak / off peak) see the example on the energysavingtrust.org.uk/rts-meter-switch-off web page rather than single dual rate meters.

https://www.diynot.com/diy/threads/faulty-meter.557170/ has another picture of one: Note the RTS unit has an un-metered input from the DNO fuse (power for the receiver/ E7 load contactor coil) as well as the Live from the meter itself via a Henley and the switched Live out.

 

[morqthana]

Buildings with storage heaters would have had their incoming supplies sized appropriately for those heaters, as electric heating would have been there from when it was constructed.

So there were never any retro-fit NSHs?

 

[SUNRAY]

If that is true then he's never paid for heating or E7 hot water since that date. Has he got pics of before and after the smart meter install?

Apologies I misled there. The heating system has not been altered, ie all the original heaters, presumably over the years repairs have been made. The current meter wiring has been altered, apparently the 2 Henley blocks were vertically between the DNO head and meter but moved to the side of the meter to provide the additional height required for the SM, but I & they have no idea if they are currently connected as they always have been, something like this

TRS installs often had two separate meters (peak / off peak) see the example on https://energysavingtrust.org.uk/rts-meter-switch-off/rather than single dual rate meters.

above link returns 404
This system?

E7 heaters

I've been out tonight to a rental flat where the tenant keeps complaining that the E7 storage heaters don't come on and they have to keep adjusting the time switches. It seems some work has been done in the 'meter cupboard' a couple of weeks ago where all 56 [peak & off peak x 28] meters live...

www.diynot.com

https://www.diynot.com/diy/threads/faulty-meter.557170/ has another picture of one: Note the RTS unit has an un-metered input from the DNO fuse (power for the receiver/ E7 load contactor coil) as well as the Live from the meter itself via a Henley and the switched Live out.

Yes that is just as I'd expect it to be connected:

However I've also seen plenty (especially where the meter is remote from the supply) where the permanent supply to the RTS is metered:

 

[SUNRAY]

Buildings with storage heaters would have had their incoming supplies sized appropriately for those heaters, as electric heating would have been there from when it was constructed.
EV charging is a retrofit to existing supplies which were not designed for such loads.

So there were never any retro-fit NSHs?

Well of course there are and initially I was generally happy to go along with another of Flameports 'generalisations' except of course a huge number of NSH's have been installed in properties built before the new fangled lectrickewy was invented.

A schoolfriends first house purchase was on a 1960/70's estate, billed as 'All Electric' however they were built with oil fired warm air central heating which filled a massive brick built cupboard, very bulky, very noisy, smelly big green tank in the front gardens. I assisted to decommision, demolish the cupboard to remove the system (which was too big to get through the metric single door), remove the airducts etc and install NSH's. The success meant he and I assisted with several neighbours.

 

[Rodders53]

This website its mangling any link I try to insert correctly to energy savings trust page so I've edited my post to remove the link. Apologies. Remove the /rather and it will go correctly.