Fischer Storage Heaters

His/her other two posts are equally informative.

Hi everyone, to let you know, we’ve had to delete many comments from this thread which were bordering on the libellous. Please, to keep the forum manageable, check and consider your forum comments carefully before posting, if they are critical of Fischer or any other brand of heating, and ensure that they’re factually correct and can be fully substantiated.

Thanks

MSE_Andrea wrote: »

Hi everyone, to let you know, we’ve had to delete many comments from this thread which were bordering on the libellous. Please, to keep the forum manageable, check and consider your forum comments carefully before posting, if they are critical of Fischer or any other brand of heating, and ensure that they’re factually correct and can be fully substantiated.

Thanks

Hi Andrea,

Without mentioning the names of any firm marketing electrical heating systems, it is apparent that MSE are having pressure applied to tone down or remove critical comments.

From scores of posts on MSE there is apocryphal evidence that potential customers are being quoted well in excess of £1000 each for a plug-in electrical heater; and indeed some have stated they have purchased at these prices.

In virtually every case, the potential customer is visited in their home by a salesman.

Despite rulings by the Advertising Standards Authority that some adverts are misleading, many still imply that their brand of heating produces more heat for the same running cost than other electrical heater.

Again from posts on MSE it would appear that some visiting salesmen make outrageous claims; or perhaps all those potential clients misunderstood!

Is it not possible that MSE could commission a report – a ‘layman’s guide’ to electrical heating? Any new poster on this subject could be pointed to that report. It would save MSE from having to remove text from posts that was potentially libellous and importantly save many people thousands of pounds.

help_me_im_lost wrote: »

They also state on their website "An average sitting room of 4m x 3m with a ceiling height of 2.4m would require a 3.4Kw night storage heater. Yet in the same room, only a 1.5Kw Fischer storage heater would be needed" ...
I have no intention of buying them, but the fledgling physicist in me has one question: out of interest, can they legitimately claim that a 1.5kw heater will heat the room better than 3.4kw storage?

Kind of, because they conveniently ignore the total heat output over 24 hours.

3.4 kW storage heater charged over 7 hours (Economy 7 off-peak period) stores 27.2 kWh. Ignoring heat loss during the charging period and assuming a steady heat discharge over the 16 hour day that equates to an output of 1.7 kWh.

A 1.5 kW non-storage electric heater running continuously for the same 16 hours will consume 24 kWh, which is about the same as the storage heater.

If the room requires approx 24kWh heat input during the 16-hour day to maintain the temperature then that is the same whether you run a storage heater on an 8-hour charge, an electric heater on a 16-hour day, or a gas boiler and radiator with a similar heat output.

The difference is in the cost of energy consumed. For 24kWh:

Off-peak electricity (Economy 7) 6.8p per kWh or £1.63 per day
Peak rate electricity (Economy 7) 17.9p per kWh or £4.30 per day

Standard electricity 13.6p per kWh or £3.26 per day

Standard gas 4.6p per kWh or £1.10 per day assuming 100% efficiency; modern condensing boilers approach this.

A non-storage electric heater will cost about twice to run as much as a storage heater if you change to a standard electricity tariff, and about three times as much if you remain on an Economy 7 tariff but use the heaters at expensive peak rate electricity.

Unit rates above are from British Gas Clear & Simple Tariff, exclude standing charge, quarterly bill, for central London.

Certainly economies may be possible changing from storage heaters to non-storage electric heaters. If you're not at home during the day, you're paying for the heat stored during the night and discharged during the day but which you don't use. If you supplement the storage heaters with non-storage heating in the evening at peak rate electricity, you may be better changing to a non-Economy 7 tariff and using non-storage heaters on a standard tariff that doesn't penalise peak use. Conversely, if you have stored hot water heated overnight, run the washing machine overnight etc you may still be better having an Economy 7 tariff. The exact break-even point depends on the balance of peak vs off-peak (day vs night) units and your supplier's tariff.

The real problem is not that Fischer et al heaters are bad heaters; they're not. However they are, in terms of simple energy efficiency, no better and no worse than a £20 convector heater from Argos. Electronic thermostats and time controls can make them slightly more economical to run, and they may be more convenient / attractive.

However sellers of similar types of heaters make claims about energy efficiency which contravene basic common sense and the laws of physics, and the heaters are very expensive to buy.