Moving from THTC to Economy 10. Will the new smart meter charge storage heaters during off-peak periods only?

Hey ​@Lecky ,

By default the upgrade would be to Smart Meters so everything would run locally.

What I can say is that they’ll be set to only allow your Storage Heaters to run during Off-Peak hours which is similar to how things work now. The biggest change however, is that during Off-Peak hours, ALL your usage is charged as Off-Peak so you’ll want to take advantage of that.

Hope this helps, let me know if you have more questions.

Hello ​@Blastoise186 

My apologies. I am new to this forum and did not realise that I could respond to your reply specifically. To make amends I copy my reply below.

Many thanks for your response.

I shall ensure that most of the energy guzzlers (tumble dryer, washing mashine, water heating top-up, etc.) are unleashed only during the off-peak hours. And, I understand, whereas the storage heaters’ ‘Comfort’ and ‘Boost’ facilities could be (with THTC) set to come on any time during the full 24 hour period at the off-peak rate, any settings outwith the three Economy 10 off-peak periods will now be charged at peak rate by the new ‘smart’ meter. I shall be reprogramming the storage heaters to minimise their use outwith the off-peak periods.

I am still awaiting an assurance from OVO that an appropriate 5 terminal SMETS2 will be installed which will be able to ensure that the automatic switching of the heater charging circuits will take place during off-peak hours only. Why OVO has not provided this information is a mystery and concerns me. Is there an undisclosed technical or locational problem? Surely not a state secret. In this instance silence is not golden.

I see.

Bear with me as I think we’ve got a way to get that advice for you. This may take some time but I’ll be back when I can.

Thank you for taking the time to annotate your photo - it makes everything so much easier to understand. It might have been better to make sure that the image is clear; it’s often the case that it’s important to be able to read the markings on the various devices and the display on the meters.

While we’re waiting for the authoritative response to your enquiry, I can say that no-one can say beforehand what type of meter will be installed. There are two or three different types currently being installed in Scotland, and it just depends what type the engineer happens to have in his van what type you get. We have heard of recent supply problems with one type, but they all adhere to the strict SMETS2 specification.

Since your storage heaters are currently on a restricted circuit, and the supply is neatly mounted in the meter cupboard, the installation engineer will normally replicate the restricted circuit by connecting it to the switched port of a five-port dual-rate meter, but it’s also possible to use a four-port meter with an external 100A contactor instead of the one inside a five-port model. This would normally behave in exactly the same way, ensuring that the really power-hungry stuff is only energized at offpeak times.

I’m sure you understand that there’s no 24-hour reduced rate for heating any more. With the new smart meter, electricity is billed solely according to when it’s used, not what it’s used for. This means you’ll have to learn to be circumspect with, for example,  direct heaters like panel heaters, fan heaters or radiators.

Hello Firedog,

Thanks for your insight.

I am aware that there will be no 24 hour off-peak storage heater output control under the new system. As I commented previously, I shall be reprogramming the storage heaters to minimise their use outwith the off-peak periods.

What I find nonsensical is the seeming inability of OVO to ensure that the appropriate smart meter for each and every property visited is available for installation by the engineer. Anything else amounts to ‘lucky dip’. 

I need OVO’s assurance that our storage heaters will be automatically charged SOLELY during the three Economy 10 off-peak periods.

With the astronomical cost of electrical energy, surely such an assurance should be immediate and definitive.

I‘m afraid you may have misunderstood what I wrote. As far as I can make out, Quantum series G storage heaters have two supplies, each controlled by a switch on the wall. One of them is the restricted (‘switched’) supply providing the power to charge up the heater core during offpeak periods. The other is a much leaner 24-hour supply providing power to the heater’s controls, its fan and in some cases its booster element. Your statement here (“… there will be no 24 hour off-peak storage heater output control under the new system ...”) doesn’t seem to be accurate. 

If the meter engineer is able to, he will ensure that the charging circuit for the storage heaters (and possibly for a main water immersion heater) is powered only during offpeak periods. If there are wiring changes needed beyond the meter cupboard to make this work, you’d have to engage an electrician to carry them out. I can’t see from your photo that this would be necessary.  

Just to keep you in the loop…

We’ve asked an expert to swing by and take a look at the thread. He might be able to swing by in the next couple of days if he’s not too busy, so please keep an eye out!

Just to add to this thread I have a similar issue in one of my flats. I am N Scotland with THTC.

There are 3 fuseboxes:

1) Normal house sockets, cooker, lights etc etc

2)3 Panel heaters, focus point fire, hot water Boost

3) One storage heater, hot water tank.

Previously 1) normal rate 2) and 3) offpeak with 3) being switched on and off over 10 hr period)

It would appear now that 1) is normal rate and 2&3) are offpeak only coming on during the 10 hours allocated for heating. Meaning we have lost heating the flat for anytime outwith the allocated 10hr window. Which obviously is not ideal.

Given there is only 1 storage (and HW tank which Im looking at fitting an instant HW heater in the kitchen instead as dont need to heat up a 100l tank just for that), I am thinking I am going to be better to ditch offpeak. When all the heating was on offpeak it was worth it, but now now. Unless you are saying that the WHOLE flat becomes offpeak during the allocated 10 hours?

That is correct. Unlike many of the legacy RTS Tariffs such as THTC, E7/9/10 switch the entire supply between Peak and Off-Peak rates, so everything will be charged the same rate at any given time of day and not just heating/hot water.

You can also boost the heating/hot water whenever you want if needed - but you’d be paying Peak rates if you do so outside of Off-Peak times.

Hello ​@rayshields 

It is my understanding that, whereas the Standard (peak) rate applied to all non-heating related circuits at all times over each full 24 hour period under the THTC system, with Economy 10 ALL electricity used during the 10 hour (3 + 4 + 3) off-peak periods will be charged at the off-peak rate. Therefore, arranging (whenever possible) for energy guzzlers (e.g. washing machine, tumble dryer, cooking appliances, top-up immersion heater) to be used during the Economy 10 off-peak periods should result in cost savings.

Hey ​@rayshields & ​@Lecky, 

Just tagging you to let you know that our friendly neighbourhood Luke has stopped by with some wonderful engineering advice! 

Hello ​@Lukepeniket_OVO & ​@Chris_OVO 

Many thanks. I take it, therefore, that the new smart meter will (or can) be programmed to charge the storage heater cores during the off-peak periods only; with no straying into the costlier hours.

As a matter of interest, how many hours of charge are currently provided each day by the soon to be defunct RTS THTC system? This information will allow me to compare the total hours of off-peak charging available under each package, so that heater output settings can be altered to compensate if necessary.

We can’t give an exact answer to that one, but THTC offered between 5 and 12 hours Off-Peak per day depending on weather conditions. There is no guarantee they’d be at consistent times though.

Hello ​@Blastoise186 

Thanks. Allows me to make the comparison. Moving from THTC to Economy 10 will mean, therefore, a change from weather-dependent automatically variable timings to a fixed ten hour daily charge, spread over Economy 10’s three allotted off-peak periods, irrespective of weather conditions. Hmmm.

Correct. But unlike THTC, EVERYTHING gets to benefit from the Off-Peak rates on E7/9/10. Use it wisely...

Hello ​@Blastoise186 

Seek Off-Peak. My motto from now on.

Hello ​@Lukepeniket_OVO 

Thanks for the reassurance.

Update. Smart meter installed three days ago. Very neatly, I must say. 

However, no user instructions whatsoever (either oral or printed) were provided. The use of the IHD, likewise, remains a mystery. Surely there must be user guides provided by the respective manufacturers. Unlike the previous two meters of the RTS THTC system, which simply provided readings of the energy used in kWh, the new system reportedly provides a varied wealth of information. In order to access this information, operating instructions are essential. Surely OVO customers should not have to trawl the internet for help.

Congratulations on your new toys 🙂

User manuals are indeed available online.
For the meter itself, Aclara SGM 1400-B series

For the IHD, there are several different types and versions being provided. If you post the make and model of the one you have, we can rustle up a link to a manual for it. The one I got had a helpful tutorial built in, so go through all the menus to see if yours has, too.

Hey ​@Lecky 

I hope you found Firedog’s advice and resource useful. We also have a helpful topic in our Forum Library, check it out below:

If you could share a photo of your In-Home Display, we’ll be able to point you directly to the correct manual, but you can find helpful topics for each on the In-Home Display Forum Library Section.

Hope this helps.

Hello ​@Firedog 

Thanks. I have the IHD3-PPMID-AAA IHD also. The packaging tells me it is a Model: CA100005 TYPE 1. Lots of digits and letters but no user guide.

Until very recently, user guides were available from the Chameleon website, but they appear today to have been taken down. I don’t know whether this is permanent or not. OVO did produce their own guide, which will still be valid in most respects. 

Hey ​@Lecky 

​@Firedog has left a really helpful OVO article about the IHD you have, I hope that was helpful. We also have a topic guide on the Forum which includes a lot of useful information on troubleshooting the IHD if you’re having any issues;

I hope this helps.

I have become better aquainted with my Chameleon IHD, and have determined that the new smart meter to which it is linked is indeed pre-programmed to switch according to Economy 10 off-peak times. The tarrifs displayed are also correct. Hooray! 

As an aside, I have drawn diagrams showing the Economy 10 timings graphically. I find them easier to read than printed lists. I have laminated A5 prints which I keep near the energy guzzlers for quick reference. If of any use, help yourselves.