Energy Efficiency FAQs
How to make your heating more efficient and cut your bills.
What is the most efficient thermostat setting?
The Energy Saving Trust recommends setting your room thermostat to the lowest comfortable temperature — typically 18–21°C in living areas. Turning your thermostat down by just 1°C can reduce your heating bill by around 10%. Avoid the common mistake of turning the thermostat up high to heat a room faster — a boiler heats at the same rate regardless of the thermostat setting.
Is it cheaper to leave the heating on low all day or heat the house twice a day?
For most homes, heating in scheduled bursts (typically morning and evening) is more economical than leaving heating on low all day. The amount of heat a home loses depends on the difference between indoor and outdoor temperature — a house left warm all day loses more heat overall than one allowed to cool slightly. Well-insulated homes retain heat better and may benefit from different patterns. Use your programmer to match heating to your actual occupancy.
Do TRVs actually save money?
Yes. TRVs allow you to heat different rooms to different temperatures, avoiding overheating unoccupied or naturally warm rooms. Studies suggest fitting TRVs and using them correctly can reduce heating bills by 10–20%. They work best when used alongside a room thermostat in the main living area rather than as the sole temperature control.
What home improvements will have the biggest impact on my heating bills?
In order of typical impact: (1) loft insulation — cheapest and most effective, saving up to £250 per year; (2) cavity wall insulation — typically saves £150–300 per year; (3) a new energy-efficient boiler — replacing a G-rated boiler can save £300–500 per year; (4) smart controls — saves 10–25% on heating; (5) solid wall insulation — expensive but significant savings for pre-1920 homes.
What is an ErP rating and what rating should my boiler have?
ErP (Energy-related Products) ratings run from A+++ to G for heat generators. All new gas boilers sold in the UK since 2018 must achieve an A rating, corresponding to a seasonal efficiency of 92%+. Heat pumps can achieve A+++ ratings due to their high COP. If your current boiler has a D, E, F, or G rating, replacing it is likely to generate significant savings.
What is the ECO4 scheme?
ECO4 (Energy Company Obligation 4) is a government-funded scheme that requires large energy suppliers to fund energy efficiency improvements for eligible low-income and vulnerable households. Qualifying measures include insulation, heating upgrades, and in some cases heat pump installations. Eligibility is based on household income, benefit entitlements, and the EPC rating of the property. Contact us to discuss whether you might qualify.
Does bleeding my radiators save energy?
Yes. Trapped air in radiators reduces their heat output, causing the boiler to work longer to achieve the desired room temperature. Bleeding radiators to remove air improves heat distribution and efficiency. It's a simple task most homeowners can do themselves — all you need is a radiator key (available from any DIY store) and a cloth.
Should I insulate my hot water cylinder?
Yes. An uninsulated hot water cylinder can lose heat continuously, costing around £150–200 per year in wasted energy. A well-fitted 80mm cylinder jacket costs around £20 and pays back within weeks. Modern factory-insulated cylinders have foam insulation built in and are far more efficient than older copper cylinders even with an added jacket.
Still Have Questions?
Our Gas Safe registered engineers cover Surrey and surrounding areas. Call for a free, no-obligation answer or to book an engineer.
Call 01483 676108Need a Heating Engineer in Surrey?
Halo Heating's Gas Safe registered engineers cover Worthing, West Sussex, and surrounding areas. Call for a free quote or to book a visit.