Economy 7 and energy usage concerns in new flat

WiserMiser

Leave both the cupboard switches on and leave the Horstmann slide switch on Manual Boost.  Then the lower heater will give a tankful of hot water which should last the day, and the upper heater won't be switched on automatically by the Horstmann.  You can tweak the lower heater's start time so that it's not heating up before midnight and leaking a little bit of heat unnecessarily in the small hours.  Set it to switch off shortly before the end of the cheap rate period.

After that it should happily run without needing much attention (well, until the meter is replaced or GMT returns).  Just press the Boost button on the Horstmann if the water occasionally runs cool before the end of the evening.

The icing on the cake would be to replace the switched outlets in the cupboard with ones which have an indicator light, then you'll be in absolutely no doubt what's live and when.  New switched outlet boxes aren't expensive.

It's not as bad as it sounds.  You just have to remember that the Horstmann is totally dumb, it has no absolutely idea what the real cheap rate times are, it'll unthinkingly keep doing exactly what it's been told to do, warts and all.  That's great, but the onus is on you to get it right.  However, now that you understand the system better, it should be quite straightforward.  Just check it from time to time, especially after the clocks change.

The thin wire is probably a temperature probe next to the tank and connected to a thermostat via the thin wire.

Simelthwate

Scot_39 said:

Thanks @WiserMiser

I didn't realise that off peak LED was just programmed time.

https://www.tlc-direct.co.uk/Technical/DataSheets/Horstmann/EL7_U.PDF

I read to much into the difference between programmed times and the "cheap period" you should program them inside.  As that implies the installer might only have set for a fraction of the period or periods. And added 2+2 together - as in simple systems like mine - the one main element is just connected to off peak restricted supply.  

(Actually I used to have a boost button - that operated one of the contactors on my old RTS switch / meter - for HW output only (separate from te ain NSH output) - haven't had or needed boost since on spit off peak E10 - as it is het 3x per day)

Sorry @Simelthwate

No need to apologise at all. I appreciate you trying to get to the bottom of this.
Yes, it seems the off-peak LED just matches programmed time, not the actual off-peak period. What a palaver.

Simelthwate

WiserMiser said:

Regarding E.On Next, you need to get them to rebill at the correct rates, night being the cheap rate.  Unfortunately there's nothing you can do if the Horstmann was switching the immersion heater on at the wrong time, that's water under the bridge and sadly it's your problem not theirs.

However, you should ask for compo from E.On Next for the serious overcharging: it should never have been allowed to happen.  Ask for £100 politely but firmly, and consider accepting £50.  Or £150 and settle for £100 if you're bold !  Go to the Ombudsman if they don't play ball.

Unfortunately you'll have to check the times and re-program the Horstmann again after the meter has been changed because the new E7 times won't be exactly the same.  The only way to be sure will be to check the new meter's display, you mustn't rely on what you are told or read because it'll be an expensive mistake forever if you get it wrong.

I see that the Horstmann programming error is my problem not EOn's, but please could you explain the compensation aspect to me a bit more? What is it that they would be compensating us for? The bill shows three times as much billed at 15.625p (295.7kWh) than at 32.143p (93.7 kWh). If they should have charged 295.7kWh @ 32.143p instead of 15.625p then they have undercharged if anything. I feel like I am completely misunderstanding the situation.

Thanks, I will remember to reprogramme the Horstmann once the meter is changed. I definitely do not want to make an expensive mistake. 

Simelthwate

WiserMiser said:

Scot_39 said:

As the post by @WiserMiser has pointed out - I think we were both mistakenly interpreting off peak LED as literally off peak from meter.

(The same way some posters here ask if the NSH or immersion spur has a LED on the switch to indicate wires live)

It's always a good idea to have an easily visible indicator on a storage heater supply so that you know when the night rate is available and you can use high power appliances more cheaply.  It also allows any unexpected changes in the times to be spotted, very important if using local timers.

Scot_39 said:

I'll leave it between you and your sister if you want to narrow down the rate timings - and if so - via the meter cabinet - or in home via a live wire connector - or listening for the NSH charging to save such trips - around c23:30 or c0730 c0830 would seem obvious test points..

It's essential to know the exact switching times if you're using local timers like the Horstmann.  You can check over a few evenings if you don't want to keep staring at the meter.  Having established the exact start time, you can then check almost seven hours later.  If it switches back after exactly seven hours then it's 'job done'.  If not, it's probably a 'split shift' cheap rate, so it would need checking almost nine hours after the cheap rate starts.

The best solution is to feed the immersion heater and the NSHs from circuits switched by the meter, then heating up anything at peak rate will be impossible unless the boost button is used.  However, that does require wiring changes and potential redecoration, which is why some people settle for the 'cheap but fiddly and risky' local timer solution.

Thanks. There aren't any indicator lights on the storage heater supply at present so I will try to get these installed if new storage heaters are put in. 

Right then, I will find out the exact start time and check approx 7 hours later. I hope that'll be the end of it.

I will certainly investigate the option to have the immersion heater and NSHs switched by the meter. My mum is planning to redo some of the rooms and probably get new NSHs so depending on the cost of the wiring changes, some potential redecoration will be fine.

WiserMiser

Simelthwate said:

WiserMiser said:

Regarding E.On Next, you need to get them to rebill at the correct rates, night being the cheap rate.  Unfortunately there's nothing you can do if the Horstmann was switching the immersion heater on at the wrong time, that's water under the bridge and sadly it's your problem not theirs.

However, you should ask for compo from E.On Next for the serious overcharging: it should never have been allowed to happen.  Ask for £100 politely but firmly, and consider accepting £50.  Or £150 and settle for £100 if you're bold !  Go to the Ombudsman if they don't play ball.

Unfortunately you'll have to check the times and re-program the Horstmann again after the meter has been changed because the new E7 times won't be exactly the same.  The only way to be sure will be to check the new meter's display, you mustn't rely on what you are told or read because it'll be an expensive mistake forever if you get it wrong.

I see that the Horstmann programming error is my problem not EOn's, but please could you explain the compensation aspect to me a bit more? What is it that they would be compensating us for? The bill shows three times as much billed at 15.625p (295.7kWh) than at 32.143p (93.7 kWh). If they should have charged 295.7kWh @ 32.143p instead of 15.625p then they have undercharged if anything. I feel like I am completely misunderstanding the situation.

Thanks, I will remember to reprogramme the Horstmann once the meter is changed. I definitely do not want to make an expensive mistake. 

They seem to be making a very basic mistake that would result in serious overcharging.  Even if initially in your favour, that would only be temporary and you'd be disadvantaged forever.  If so, there's really no excuse because it's so obvious, the whole point of E7 is that the night rate is always lower to allow heat to be stored, full stop.

Wait until the problem has been resolved and then request compo if, as seems highly likely, there's simply no excuse for having made such a mistake: it has wasted your time,  caused worry and would have resulted in ongoing financial losses.

You may well find that compo is offered automatically.

WiserMiser

Simelthwate said:

WiserMiser said:

Scot_39 said:

As the post by @WiserMiser has pointed out - I think we were both mistakenly interpreting off peak LED as literally off peak from meter.

(The same way some posters here ask if the NSH or immersion spur has a LED on the switch to indicate wires live)

It's always a good idea to have an easily visible indicator on a storage heater supply so that you know when the night rate is available and you can use high power appliances more cheaply.  It also allows any unexpected changes in the times to be spotted, very important if using local timers.

Scot_39 said:

I'll leave it between you and your sister if you want to narrow down the rate timings - and if so - via the meter cabinet - or in home via a live wire connector - or listening for the NSH charging to save such trips - around c23:30 or c0730 c0830 would seem obvious test points..

It's essential to know the exact switching times if you're using local timers like the Horstmann.  You can check over a few evenings if you don't want to keep staring at the meter.  Having established the exact start time, you can then check almost seven hours later.  If it switches back after exactly seven hours then it's 'job done'.  If not, it's probably a 'split shift' cheap rate, so it would need checking almost nine hours after the cheap rate starts.

The best solution is to feed the immersion heater and the NSHs from circuits switched by the meter, then heating up anything at peak rate will be impossible unless the boost button is used.  However, that does require wiring changes and potential redecoration, which is why some people settle for the 'cheap but fiddly and risky' local timer solution.

Thanks. There aren't any indicator lights on the storage heater supply at present so I will try to get these installed if new storage heaters are put in.

I will certainly investigate the option to have the immersion heater and NSHs switched by the meter. My mum is planning to redo some of the rooms and probably get new NSHs so depending on the cost of the wiring changes, some potential redecoration will be fine.

To eliminate the risk of charging at peak rate, each High Heat Retention NSH will need a 24/7 supply for the control system plus an overnight E7 supply switched by the meter.  Some HHR NSHs have a built-in instant boost heater to allow daytime top ups (a bit like the Horstmann button).  Make sure the new heaters are not programmed to allow this to happen automatically, and if in doubt about the heater size get the larger version.

You don't want to end up with some that are too small and keep needing expensive top ups during a big freeze.  Just like the Horstmann, best to understand the system and program it yourself rather than rely on the defaults or what the installer decides.