Help needed post THTC

  • 28 November 2023
  • 5 replies
  • 166 views

My parents-in-law live in Argyll & Bute and have THTC.

They have been told that next year this tariff will end, and they will have rewiring to convert their system to Economy 7.

 

As I understand it THTC is controlled by the energy company  and the exact times when it comes on is governed by daylight times and weather conditions.

They have convector heaters (not storage heaters) connected to the THTC meter, but they do not control them at all, they simply go on and off whenever the THTC is switched.

To control them is an impossible task – they are elderly, immobile and the controls are extremely confusing – even to an able body like myself.

 

The amount they pay for their electricity is, quite frankly, astonishing – they have a ground floor stone built 3-bedroom flat and pay £400 - £600 / month depending on the time of the year.  They are in fuel poverty.

 

My real concern is that when the changeover happens next year, the E7 circuit will replace the THTC circuit but that the heaters will draw power all day long and cost even more than they do now – I shudder to think how much more this will cost them.

About 3 years ago my father-in-law took a grant to replace all the heaters.  Previously the heaters were storage heaters and got replaced by convectors - presumably because with THTC it was more economic.

I really need answers to these questions…

 

Is my assertion that when the rewiring occurs all their convector heaters will draw power on the E7 circuit 24 hours a day? (I appreciate the rates will change at night).

Is there any help that they could use to resolve their issues? e.g. retro fitting a central control system, 

Can they delay the conversion until they have had a chance to resolve any issues?


5 replies

Userlevel 7
Badge +5

Hi @sibur , sounds like a difficult situation. 
E7 works by providing off peak power at a lower cost than peak and is therefore usually used with equipment such as storage heaters which can power up at a lower cost and deliver heat through the day. I don’t know how this would be useful with convection heaters. 
THTC will need replacing but there are discussions ongoing in terms of timing as the replacement metering equipment is not normally a straight swap. 
I would suggest a review of the whole heating requirements as it sounds like it may be necessary to swap equipment again 

@BPLightlog thanks.  I feared as much.  This is going to cost a lot of money - I can see it.  I did wonder if is possible to retrofit some sort of control that can use wifi to a central unit that could switch on each radiator thermostatically / by times.  I have googled it but not sure if anything like that exists. 

Thinking it would be technically possible by inserting a box between the power and the radiator that switches the unit on/off depending on a central control - via an app and/or wall mount controller.  Is this a possibility do you think? 

Userlevel 7
Badge +5

@BPLightlog thanks.  I feared as much.  This is going to cost a lot of money - I can see it.  I did wonder if is possible to retrofit some sort of control that can use wifi to a central unit that could switch on each radiator thermostatically / by times.  I have googled it but not sure if anything like that exists. 

Thinking it would be technically possible by inserting a box between the power and the radiator that switches the unit on/off depending on a central control - via an app and/or wall mount controller.  Is this a possibility do you think? 

The problem will be that a convection heater will only offer heat when being powered, hence the off peak/storage heater combination. 
Any new meter will look at switching circuits itself automatically so any control is usually taken care of. 
As I mentioned, THTC is being discussed. It won’t suddenly stop but without a signal (the main problem with obsolete components) will continue in its last know setup from what I understand. 
There are a number with this sort of setup and a few threads about it as well 

but from your comments, I think any solution which doesn’t use off peak storage of some sort might not be the best for your parents and be rather expensive to operate

Userlevel 1

Hi, You may want to consider fitting radiators that your parents can switch on and off themselves and that have some sort of automatic thermostat control.

We have THTC in our house with three storage heaters for which the charge up times are controlled by the RTS signal . The hot water works the same way. We also have panel radiators which are fully controlled by us. The radiators are connected to a 24/7 low THTC tariff through the THTC meter. I think your parents radiators should be rewired to run through this circuit if they don’t already do so. 

The RTS signal was due to end in March next year but there is speculation that its life will be extended as there are still many users dependent on it. 

 

Userlevel 1

Another alternative to consider is to have all your radiators and hot water connected to the standard rate meter. They will have to be switched on and off by your parents and will not be effected by the RTS switch off. There supplier should then take away the THTC meter.

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