Reported by The Guardian
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Samuel Gibbs doubted he could cut costs and still keep warm by putting tech in control. The results surprised him
C an smart thermostats and AI reduce your heating bills? Every manufacturer claims the answer is yes , quoting average savings in the 25%, or £180 a year range. But all of these promises are heavily caveated and, with energy costs changing regularly, it can be very difficult to tell what is having an impact.
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To find out if technology can really help, I spent the last two years comparing my miserly manual control and basic heating schedule to an AI-governed system. The results surprised me.
I used my 1930s solid-brick house with a recent, insulated loft conversion as the test bed.
In the winter of 2024 my heating system consisted of a 10-year-old Worcester Bosch combination gas boiler set to a medium heat, a Hive thermostat in a central hallway with its smart features disabled and 13 radiators equipped with standard thermostatic radiator valves (TRVs).
To maximise energy savings, I set a basic schedule to turn the heating on for a couple of hours in the morning and evening, turned off the TRVs in rooms we did not use and manually adjusted those in other rooms when we did not need them to be heated. I also manually turned the heating off when leaving the house.
It was laborious and not all that comfortable at times. I frequently found myself being glared at by other members of the family who were shivering under blankets in the living room while watching The Traitors. Or being called a traitor after denying yet another request to turn up the heating. But it kept bills low throughout the winter and money in my pocket.
After controlling for hot water usage by using recordings from when the heating was not used during the summer months of 2025 to create a daily average, my manual control consumed 14,316.7 kilowatt hours of gas across 213 days from…