Night storage heaters and the costs

Scot_39

Your getting confused

Energy  = power x time 
Cost = energy x rate per unit


77.2 kWh / 7 hrs  = 11 kW  - the total power rating - it has nothing to do with getting Cost in p/£

Cost on bills = kWh used x unit rate in p / kWh.

77.2 kWh X 15p / kWh = £11.58

You would have to have programmed peak tines and use boost mode 10+ hrs a day to get near £25

The actual charge rate the power rating likely to be 19.3kWh/7 = 2.75kW. 

Cost = 2.76kW (*) x 7 x 15p per heater max x 4

- unless use daytime boost

Similar to Dimplex qm125 series input rating, which is hardly surprising given they are basically a rebadged version of same tech non rf series I guess quantim iirc.

The manuals are near identical to early series quantum pagd for page

(*) See here for list of documents 

https://www.cef.co.uk/catalogue/products/4882612-1kw-dynamic-hhr-heater-white?srsltid=AfmBOoq855rYJcszxpepq1rjILq36PPu57s1Nyl7jyirNl2ZFE-HuRoAFAo&gQT=1


Well worth a read and then maybe armed with instructions - maybe worth trying again.

If your night rate is 15p - your day rate likely to be closer to 30p.

Double tge energy if can  use it well - and with those heaters you definitely have a good chance you might be able to.

Of course rf quantums with hub would be a better match if away a lot to your smart remote control of panels. 

Gerry1

Yes, the problem is likely to be that you are not using them correctly.  If you haven't studied the instructions carefully and programmed them yourself then it's guaranteed.  Using default settings or what the installer programmed is unlikely to meet your specific requirements.

Not having a go at you, but here's my evidence that you haven't done your homework properly:-

37pisntenough said:

4. It's really irritating if I am away and return to a cold house (I switch the heaters off when I'm away) I can't get any heat until the next day.

You haven't spotted that they can be programmed for to 'wake up' the evening before you return so you won't have to return to a cold house.  Ditto, you could switch on the Boost to get some instant heating.  You should normally leave the heaters switched on, even when away, and programme the days when you want heating and the specific times and temperatures that you require.

The Boost uses expensive daytime electricity and should be considered as a last resort when something throws a wobbly, e.g. you returned from holiday earlier a day or more before expected, or there's a sudden 'Beast from the East' that wasn't forecast.  If you're using Boost frequently then you’re doing something wrong.

That's one example of sub-optimum usage, and there are probably others.

Study the manuals, check all the settings and you'll probably see some improvements.

https://assets.cef.co.uk/downloads/pdg/heatstore_hsds_quick_start_guide/heatstore_hsds_quick_start_guide.pdf

https://assets.cef.co.uk/downloads/pdg/heatstore_hsds_user_manual/heatstore_hsds_user_manual.pdf

Also, what are your E7 rates?  They vary quite significantly between the different tariffs.

Finally, make sure you're only using the immersion heater at off peak times.  There's often a second element fitted higher up the tank and connected to a 24h circuit.  Make sure it's left switched off otherwise a lot of your hot water will be heated at the daytime rate which will be even higher than the single rate tariff.

EssexHebridean

Definitely don't turn storage heaters off while you're away at this time of year - instead turn the input down so they still charge a little, enough to keep the cores warm, but not enough to really heat the home. 

NSH's can be absolutely brilliant - especially the modern high heat retention ones - but only so long as you really put the time into learning to use them effectively. Modern ones are programmable so that they release the heat when you need it, and that gets around the issue of them running out of heat in the evening, always a recognised issue with older ones. 

If you stick on E7 then also note Gerry's paragraph above about checking your timing for the immersion heater as well - we've seen a LOGT of people here paying a fortune thanks to one of those being used out of optimum timings! 

Stubod

We recently changed a (30 year old) old NSH for a Quantum. The old SH "leaked heat" and was cold by about 5:00 pm. We have programmed the Quantum for "out all day", (although we are mainly in). This seems to work fine. 

We programmed it for the "comfort mode", (ie when the blower kicks in) to come on around 7:30AM for an hour, and again in the evening between 5:00 and 8:00pm, but we normally find we can manually turn the comfort mode off around 5:30pm.

GibbsRule_No3.

37P,  the Dimplex Quantums can be programmed to come on the night before you return from being away, you can even buy a gadget with an App to control from phone or laptop. Mine, with an large immersion water tank for taps shower, costs under £5.00 a day at present and I'd reckon at least a £1 of that is water, probably £1.50 - £1.75 for cooking and kettle. 90p Standing Charge. Really good value to me at least. Way better than the old ones I'd been using for 8 years.

bob2302

Stubod said:

We recently changed a (30 year old) old NSH for a Quantum. The old SH "leaked heat" and was cold by about 5:00 pm.

Was that with it on minimum output during most of the day?

EssexHebridean

bob2302 said:

Stubod said:

We recently changed a (30 year old) old NSH for a Quantum. The old SH "leaked heat" and was cold by about 5:00 pm.

Was that with it on minimum output during most of the day?

Can't speak for the OP but our old ones roughly performed to that pattern regardless of the output settings. what little insulation there was had largely broken down over the years and it was pretty ineffectual to start with! 

QrizB

bob2302 said:

37pisntenough said:

Gerry1 said:

What's the make and model number of each heater?

Does each heater have one mains connection or two?

They are Heatstore model HSDHHR125.

These have a capacity of  19.3 kWh; if you are charging 4 at £25 a night, that implies a unit rate of at least 32p/kwh.

Thanks @bob3202 I was reading through three pages of this thread and waiting for someone to do that calculation!

The most likely way for four of those storage heaters to cost £25 when charging is if they've been programmed with their charging times (instead of using the E7 switched supply) and those times not matching the E7 cheap rate period.. This would be consistent with the property having previously had panel heaters, so no E7 switched wiring to the NSHs.

OP do you have a smart meter or a dumb one? How many big thick wires come out of the bottom of it, four or five? Are there any thinner wires too? Would you be able to share a photo of your meter and your fuse box(es)?

tamste

Do you run the night storage heaters on E7?

If not, this probably indicates why they are so expensive to run. Maybe the landlord just fitted NSH's to satisfy the council, but didn't set them up for E7 usage, so you would be paying peak rate to charge them, which isn't going to be cheap.

For context, I have 13 modern storage heaters (mix of Elnur HHR and SSH's) with +2 x bathroom radiant heaters in a large rural bungalow, all of which are active. I use ~ 100kWh per day this time of year, and it costs me ~£15/day on an "in all day" program setting. I also have solar (10 kW system) to offset the total cost over the year, but this time of year it doesn't save much.... its the balance over 12 months that works for me.

mjm3346

37pisntenough said:

Thanks to everyone who contributed to this. 

I've found my answers now and in spite of others having different experiences I have switched off my night storage heaters and will be using plug in heaters.

This has several advantages to me
1. As I'm away quite often I can get instant heat when I return rather than waiting until the next day. By using WiFi connected heaters I can warm the rooms up I need remotely so when I get back the house is warm.
2. It reduces my costs!
3. I'm not storing heat (and paying for it) that is either insufficient or wasted.

Thanks everyone for the views.

I have 3 Dimplex heaters (10+ years old) E7. I want most heat between 5pm and midnight, the storage heaters produce least then and on colder days run out by the early evening, a couple of convector heaters are more useful/flexible and cheaper (E7 rate outside the E7 hours is about 25% higher than the standard rate)