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Smart Thermostat Habits to Help Save Money

Published: 02 Oct 2025 ・ Read time: 6 Mins
With UK homeowners experiencing yet another round of energy price cap hikes, it’s little wonder we're turning our attentions to warming our homes as the temperatures begin to dip. One area that can help when actively looking to cut down on energy bills is the thermostat.
With heating typically the largest part of the energy bill for so many of us, these innovative devices can help you regulate your home's temperature more efficiently, leading to significant savings over time.
Here at City Plumbing, the home of heating, we discuss some smart thermostat habits that can help you use your thermostat effectively this season and beyond to keep you warm without wasting energy or money.

How to Use Your Thermostat Wisely for Maximum Efficiency

1. Find Your Ideal Temperature (And Stick To It)
Most energy experts, including the Energy Saving Trust, recommend setting your thermostat between 18°C and 21°C for comfort.
  • For Savings: Most energy experts agree that setting your thermostat to the lowest temperature you are comfortable with is the single best way to save. Dropping the temperature by just 1°C can reduce your heating bill by around 3% to 4%, which can translate to significant savings over the winter.
  • Don't "Blast" It: Turning the thermostat up to 25°C or 'max' will not make your boiler produce heat any faster. It just sets a much higher target temperature and ultimately means the boiler will keep running longer. The boiler will run flat-out until the room reaches that high temperature, often causing the room to overshoot your comfortable level and wasting energy when the room eventually overheats.
  • For Health/Damp: The World Health Organisation (WHO) recommends a minimum temperature of 18°C for healthy adults. Dropping below 16°C is generally not recommended, as it risks condensation, dampness, and related health issues, especially for vulnerable individuals.
2. Time It Right With the Programmer
Your thermostat works with your heating programmer or schedule to ensure the heating is only on when it needs to be. For the vast majority of UK homes, it's cheaper to only have the heating on when you need it.
  • The Myth: The idea that leaving the heating on low all day is cheaper is a common myth. While leaving it on low prevents the house from cooling completely, your boiler is constantly using energy to replace heat that is naturally escaping through walls, windows, and the roof.
  • Heat On Earlier, Not Hotter: Instead of waiting until you feel cold and turning the temperature up, set the heating to come on 30 minutes before you wake up or arrive home. This warms the building fabric and air gently, which is more efficient than a short, intense burst.
  • Turn it Off When You Sleep/Are Out: Reduce the temperature significantly or switch the heating off completely when you are asleep or the house is empty. For most homes, it is cheaper to allow the temperature to drop and reheat when needed, rather than maintaining a high background temperature all day.
3. Utilise Thermostatic Radiator Valves (TRVs)
The thermostat controls the temperature in one main room (where it's located). TRVs, which are the numbered dials on your radiators, allow you to control the temperature in every other room individually. TRVs allow for zonal control, ensuring you only heat the space you're using.
  • The Rule: Your main thermostat controls when the boiler comes on; the TRVs control how much heat goes into individual radiators.
  • Balance the House: Set the TRV in the main thermostat room to fully open to the most comfortable temperature (usually 5 or 'max'). For unused rooms (like a spare bedroom), turn the TRV down to the lowest number setting (eg. 1, 2, or 3) or the frost protection setting. This will prevent them from drawing water from the boiler unnecessarily, thus saving energy.
  • Don't Set the TRV Higher than the Main Thermostat: If your main thermostat is set to 20°C, the radiators in that room will only work until 20°C is reached. Setting the TRV in another room to 'max' won't make it hotter than the main target temperature allows.

Common Thermostat Mistakes Many of Us Make - And How to Fix Them

Mistake: Placing furniture or curtains over the thermostat
  • Why it Wastes Energy: The thermostat cannot accurately sense the room's true air temperature, often leading it to believe the room is colder than it is, resulting in excessive and wasteful heating.
  • Smarter Habit: Always keep the thermostat clear and ensure air can circulate freely around it.
Mistake: Turning the thermostat up to "max" (e.g. 30°C) to heat the room faster
  • Why it Wastes Energy: The boiler will run for a prolonged period until it reaches the high set point, causing the room to significantly overheat and waste energy. It won't heat the room any faster than setting it to a comfortable temperature.
  • Smarter Habit: Set it to your comfortable target (e.g. 20°C) and let the system do its job. To heat up faster, adjust your heating schedule to start earlier.
Mistake: Trying to control the main boiler using Thermostatic Radiator Valves (TRVs)
  • Why it Wastes Energy: TRVs only control the individual radiator they are on. If you turn all your TRVs down, but the main room thermostat is still calling for heat, the boiler may still fire up unnecessarily.
  • Smarter Habit: Always use the main room thermostat or programmer to tell the entire heating system to switch on or off. Use the TRVs only to control the temperature of individual rooms.
Mistake: Not using a schedule (or leaving the heating on 24/7)
  • Why it Wastes Energy: You're paying to heat your home when you aren't there or when you're asleep, allowing unnecessary heat loss.
  • Smarter Habit: Program your heating for specific times to match your routine, or use the "Away" or geofencing feature on a smart thermostat to reduce heating when the house is empty.

Buy Thermostats From City Plumbing

City Plumbing offers a wide selection of thermostats, all designed to help you maximise the efficiency of your home's heating system. From sought-after brand names such as Drayon to Honeywell, Hive to Worcester Bosch, and many more, we ensure a choice of high-quality products that you can rely on all year round.
Ultimately, by adopting smart thermostat habits, you can help save money on your energy bills while also reducing your environmental impact. By finding that perfect temperature, using the programmable timer to the best of its ability, and gaining a better understanding of TRVs, you can create the perfect temperature in comfort throughout the home this season and beyond.
If you’re looking for helpful advice and suggestions on choosing the best heating solutions for your home, take a further look at the City Plumbing website for more information.

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