Gas consumption

[FRISKA]

My wife and I live in a three bedroom bungalow with gas central heating etc but electric cooker. Combi boiler 12 years old. Our plumber/gas engineer tells us that it is more economical to run a gas fire than to have the central heating on even though some radiators are only on a low setting. N-Power, our suppliers, tell us the opposite. They say that is cheaper to run the central heating than the gas fire. Anyone with advice please ?

N-Power have at different times told us that they consider gas consumption for two people in our situation should be from 3 to 6 units per day (gas meter reading). They state that heating should be on a couple of hours in a morning and a few more in the evening.
Again, any comments please.

[KARL]

The cheapest option of all is not to use any heating. What you need to do is decide what level of comfort you want and then decide whether you can afford that. Timing your heating means that there are periods when there is no heating (example you gave) and during those the temperature will steadily fall. On a cold day/night it will go to whatever the heat losses dictate (draugh-proofing and insulation matter a lot). When the heating comes on it has to make up that loss and drive the temperature up again - everything from furniture to walls and floors need to be heated, and the output capacity of the system (typical designs are inadequate to meet this requirement) will limit how quickly this happens. This severely challenges most systems if only given two hours to do it, and meanwhile the place feels draughty/chilly because of all the cold surfaces. The chances are that the heating will be running flat out while it is on. If you are lucky, things are just approaching lukewarm when the guillotine of the clock comes down. In my experience (four large bedrooms plus generous others), it is better to leave the heating on constantly and have a well placed thermostat control the heat demand - as low or as high as you choose, even over different periods (away/night times low, in/day times higher - all by perhaps 3-4 degrees). This I find is no more expensive (in fact cheaper) than the other feast-or-famine regime, but that assumes a modern-conditions (almost foreign) house. With/if Victorian single glazed windows, practically no insulation, and all the general draughts (including fireplaces) means that you are on a hiding to nowhere. As for using a gas fire, much of the heat goes up the chimney and those things provide comfort levels akin to a Guy Fawkes bonfire in a field - but I have no direct experience of their use or their economics that I can advise on.

[KARL]

We used approx 30000kWh or 1700 meter units annually to maintain a minimum of 18 degrees (out/night) and usually 21 degrees (in/day) throughout the house plus all hot water needs in a below average UK temperature zone.

[buildersmate]

An absolutely brilliant but long answer. This man deserves some stars.

[FRISKA]

Thank you Karl for your informative contribution.Most helpful.

[BertiWooster]

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