[MargaretR]

Although my one bedroom flat is smaller than most of your homes, I do have my heating and hot water on 24 hours a day - controlled by my thermostat set at 23C, sometimes 24C.
I noticed a big drop in costs when a condenser boiler was installed spring last year.
At current prices I will be spending £507.99 a year.
Scottish Power Online Energy 3 tariff with dual fuel and Online discounts.
All my lightbulbs are energy savers. I have good insulation.
I check with the switching sites often, and have switched 5 times in 6 years.
The way to get the best deal at switching is to enter your KWH per year usage in the calculation on the switching site.