Another E7 "Help Me" Thread. Old NSH, Vented Cylinder, Electric Shower (!?!)

ch_152

Hello all,

Another person here who has just moved into a flat with electric only, which is currently running E7 and with a mixture of appliances that take advantage of the night-time rate (NSH, immersion heater) and some that don’t (electric towel rail, electric shower).

I’m looking at options for upgrading various elements, as much for convenience and ease of use as for economic reasons, but I obviously don’t want to waste money. I’ve read a LOT of threads here on MSE and they’ve been very helpful.

The main questions (context in "the long version" below):

• Hot water: I don’t want to shell out for piped radiators with an electric combi-boiler. So, in terms of hot water, immersion seems most sensible regardless of E7 or flat rate? And with E7 it’s even more sensible? I understand it will require upgrading to a unvented cylinder if I want to run my shower from it (currently electric shower run off mains water) as the water pressure is rubbish from the vented cylinder.

• Heating: On an electric only tariff, are high heat retention night storage heaters still generally considered the way to go? I’m not likely to make a move on it until later in the year. I had heard about EPCs being negatively effected by changing NSHs to normal electric heaters on a flat rate?

• My usage for the last couple of months has been around 10 kWh/day and 20 kWh/night. Does this seem high? (I think it could be, in part, skewed because of needing to run supplementary plug-in heaters during the evening during the colder weeks we had recently).

• E7 tariffs seem to carry some risk, in relation to more volatile price changes. I’m currently on “Flexible Octopus”. Is there anywhere you can easily compare the day/night tariffs of suppliers? 

• Is E7 going to die out? I have read some speculation that it may be phased out (in which case investing in NSH might not be smart).

Thanks in advance!

The long version…

It’s a split level flat (second and top floor). Cavity walls have been done and has decent double glazing. I’m not sure about roof, but generally the flat is well insulated with the exception of the bathroom.

The flat currently runs on E7, but with a mixture of appliances:

• One large NSH in living room (I usually run output on minimum, input depending on weather.
• Immersion heater for hot water to taps (set using a timer to run between 3 and 6am)
• 9 kW electric shower (usually used outside of night-time tariff)
• Electric towel rail in bathroom

My day/night usage seems quite high, especially during the day, but I think this is mostly down to needing to often run additional heaters for a couple of hours in the evening, along with the towel rail in the bathroom and a dehumidifier most days after a shower. Hoping these should all drop off quite significantly now it’s starting to warm up.

Storage Heaters

So I actually don’t hate the storage heater in the living room. Or at least I hate it less than I expected to.  

My main issues (as most have with old NSHs) are that when it’s cold outside, the thing has run out of heat by the evening. And usually the room is roasting in the mornings (evening with input/output on minimum) so I end up opening the windows. During the coldest spells in the last couple of months I have ended up running an additional heater next to my desk for a few hours during the day/evening, and also a plug-in heater in the bedroom for a couple of hours before bed and before waking up (both on day rate, equating to around 2-3kWh per day).

Initially, I was thinking of replacing this (and fitting the flat out generally) with some panel heaters or other electric radiator and running a flat rate tariff. But general consensus seems to be that a storage heater is more sensible, and that newer HHR models are significantly better and may get around me being cold in the evenings? I’d also like to get a smaller one so I can fit a corner sofa in…

Thoughts?

Hot Water

Currently there’s an immersion heater in a vented cylinder, without a boost function. It heats up between 3am and 6am on a timer and I’ve never run out of hot water. That said, the water pressure is absolutely pants, so there’s been an external pump fitted to this and the cold water that feeds the upstairs bathroom from a tank.

The electric shower runs off mains water, so uses day rate electric (I’m not often up for a shower before it switches, and usually shower after getting back from the gym so would miss it anyway).

I was thinking of going for a bigger unvented cylinder to be heated with the immersion heater overnight, I understand that this can provide better pressure overall so I might be able to get away from using the electric shower, which should provide significant savings. Will post a separate thread on the unvented cylinder decision in the “In my home” section. 

Does that sound like the sensible approach?

Other Considerations

I’d read in a few places that changing heaters from NSH to normal electric heating is likely to effect the EPC negatively. As it stands, the EPC is a D (due, mostly, to the old storage heaters and also due to the assumed lack of insulation to the roof). Is this true? In which case it would probably be a bad move to move to normal electric heaters on a flat rate if I every want to sell the place (not likely to be soon!).

Thanks in advance (again).

Chris

Gerry1

If you're in the Southeast region your E7 times are likely to be 2330 - 0130 and 0330 - 0830 BST so your immersion heater could be clocking up a lot at peak rate!

Scot_39

HHR panels are reportedly very good at removing that overly warm 7am cold by evening cycle.

I have doggedly kept E10 despite the price differences - as have the old style bricks NSH - which in midlands - actually charges 3x a day to a lower setpoint - to help smooth it, a neighbour swapped to E7 on same old bricks NSH - to save on tariff, but they fitted Quantums by following spring - same problem - running out of heat.  Not sure about savings on bills - but they were pleased they did it.

A few of the regulars who have recently fitted or ran for years will confirm soon I am sure.

And I think are probably a far better switch to than normal panel heaters - for EPC and resale - consumers who are energy savy may avoid the flat if have better options elsewhere. Sure read here from MSErs has improved EPC - resale ?

If your worried re E7 demise - the manufacturers are or were working on it - Dimplex was doing an app tie up with Ovo - who were actually selling a package heater and tariff deal at one stage - but EDF ran a trial as well using same tech.

If that failed or failed to gain traction - then current state - not sure - but the 2023 Quantum manual has had a small section on "variable charge time tariffs" added - a pretty clear hint of their hoped for solution.

For flats etc - air source heat pumps and air to air compressors through walls problematic - so I hope the smart NSH does come to fruition.

Smart switching - not fixed time slots - has perhaps already arrived for EV charging, Octopus IQ etc

Spoonie_Turtle

In terms of the EPC, while it may be a consideration I'd have thought the actual cost difference between heating methods would be more important.  Modern storage heaters are reportedly miles better than the old ones.  Panel heaters are ridiculously expensive to run on flat rate and even worse on E7. 

The only electric wet central heating worth considering is using a heat pump, but those are expensive to install and not suitable for every home - as you're in a flat I'm not sure it would be an option for you.

Alnat1

Small saving, could you shower at the gym instead of after the gym?

ch_152

Thanks for the replies. I did check (by staring at the meter for ages when I thought it switched based on an analog clock looking thing hooked up to the meter) and it's around 00:30 to 07:30.

Scot_39 said:

HHR panels are reportedly very good at removing that overly warm 7am cold by evening cycle.

...

This is very useful, thanks. Especially parts on the future of E7. Good to hear manufacturers are already hoping to be ahead of (or at least on) the curve when that change does come. I obviously don't really want to invest in HHR NSHs that don't have that flexibility if the time-based variable rate tariffs as we know them are indeed going to change.


Showering at the gym is a fair point, and I was doing while I was having some work done in the bathroom to fix a leak - I didn't think of it from a money saving perspective though. That said, I find stepping in other peoples foot water a bit gross (especially when the shower cubicles also have toilets in...).

littleteapot

If you are planning to stay in the flat for a number of years to come, and the cost/upheaval/viability of migrating to a wet heating system using an ASHP rules this out then I'd (personally) go down the following route:

1. replace the old vented IH cylinder with a modern, unvented, well insulated one to benefit from E7 hot water heating for the shower. Modern cylinders such as the Gledhill Stainless Lite or Stainless ES range can easily maintain a good temperature for 2 days+ provided the surrounding pipework is well lagged.

In the event that in future E7 is replaced by variable TOU tariffs there will certainly be intelligent wall-mounted 'smart' IH timers available which will be easy to fit and manage this.

2. replace the old NSH's with modern programmable HHR ones to benefit from the E7 tariff without the hot morning/cold evening issues that you get with old NSH's. However it's a difficult time to decide which NSH to get as although the manufacturers are all looking at options regarding future variable TOU tariffs (Dimplex seems to be ahead of the game on their quantum range) but currently that seems to be tied to one supplier - OVO) there are no fully flexible - i.e. completely workable with any supplier/tariff options on the market yet. And even if you buy a dimplex quantums now, there is no guarantee that there will be an easy or cost effective path to upgrade them should an 'open' solution become available in a couple of years time. 

However I wouldn't worry about this too much as I suspect E7 or a similar cost effective TOU tariff will remain for many years to come. It just might not be quite as cheap as the variable TOU tariffs. If I wanted to replace them NOW, I would still go with Dimplex Quantum or the much cheaper but not-quite-HHR Creda TSRE range. These are still reportedly very effective at retaining heat into the evening and as made by the same company (GDHV) have a very similar and flexible control system.

RedFraggle

Highly recommend quantum NSH. I have 2 across the living areas and and old box of bricks NSH in the hallway. 
I have Dimplex fans in the bathrooms as they're only on for showering.
I use my electric shower despite having an E7 thermal store that feeds the mains shower in the main bathroom at mains pressure. When I do the bathrooms I'll change the one in the en suite to mains. 
I wouldn't dream of swapping to panel heaters as I intend to stay here so the outlay on HHR NSH is worth it. 

EssexHebridean

Flipflops are your friends for showering at the gym - I can't be doing with standing where other people have had their feet either, I come from a generation with strong memories of the shame of the verucca sock at school swimming sessions... 

Long-termer on E7/NSH's here. We have a combination of older box of bricks style, VERY old box of bricks style, and a single modern HHR quantum. Our standard use is fairly recent box of bricks in the living room (18' x 11' space, roughly) with output minimum input according to temperature outside. That does retain heat right through the day so long as the input is high enough - you can't get away with economising much there, but it is also not a complete money-guzzler which I think most people believe NSH's to be. The hallway has the quantum which is a whole world of difference. We've had ours a few years now - it was fitted in 2019 - and I'm still learning about it all the time, this year's learning curve was really beginning to trust that it will adjust as needed for the weather - it really does! Just the factor that it lets out heat when we want it to and not when we don't makes a huge difference - and although it retains heat excellently there is still enough background warmth from it when charging that it serves to take the chill off the centre of the flat which is ideal for us. The other two heaters are both box of bricks - and both in bedrooms. They are also both firmly switched off as otherwise we just get too hot. Of those though the older of the two (A Creda model that we think must be around 40 years old) is by far the more effective - it was originally in the hallway and we actually had it re-sited to replace a previous heater in the spare room that had gone U/S.  Our other heating is also via a heated towel rail in the bathroom - we find that running this for a few hours during the night means that it's warm enough in there at the time we particularly want it to be - when we get up in the morning - and after that the heat from the hallway heater permeates through there anyway. That means we can use the rail on the off peak rate of course. 

In your position if finances allowed I would not hesitate to go for Quantums. The added advantage they have is that if needed - for example you and the heater get caught out by an unexpected drop in temperature - you can use the additional boost element to add a burst of warmth albeit of course at the far more expensive peak rate. It can still be useful from time to time though. If the cost of the Quantum is a step too far then the suggestion made above for the Creda TSRE range seems to be a good one - from what I have seen of them they are very effective.

Can you adjust your showering habits to make sure that you DO use it on the peak rate? And as others have said - showering at the gym is of course a definite perk to make use of -you pay your membership, you may as well get the most you can from it! 

ch_152

Thanks for the replies all. Sounds a lot like the vented cylinder and HRH NSH route is the way to go for now then.

(And showering at the gym, or the office once I start cycling in to work again now that the days are getting longer, should also be a big saving).

Scot_39

A 10m shower takes say 1.5kWh energy - c50p - at c34p epg.

But say 25-30p off peak e7 and maybe 60-70p at peak.

My immersion heater probably uses 2-3kWh+ summer, 3-4kWh+ winter to heat the tank - for normal uses - rinsing hands dishes etc.  A lot more after a bath etc. But at off peak rates.  

The heat is not wasted in winter - it heats the airing cupboard and I even open the door sometimes to heat the hall - but in summer ?

Its vented to cold water in loft - so to my mind a bigger health risk if not kept hot than a sealed system.

Its possibly a big chunk of your summer use - but not of winter - where heating alone maybe 20-30kWh.

Would suggest prioritising work accordingly on that basis..


As to potential smart heaters control,  came across a link in another thread here - suggesting devices could say scan meters HAN, the same way as the IHD does to get tariff rates etc.  But given how weak the HAN signal on mine is now, not sure I'd want to rely on it.