Turn Your Gas Boiler Down? Here’s What It Actually Saves

Adjusting your boiler flow temperature is one of the easiest ways to improve heating efficiency and reduce your gas bill. In this video I look at what “flow temperature” really means, why return temperature matters for a condensing boiler, and how much different boiler efficiencies can change the annual cost of heating a home. I use a simple example of 10,000 kWh of useful space heat and compare gas boilers running at 80%, 85%, 90% and 95% efficiency. I also go through what I did in my own house before fitting a heat pump. My gas boiler originally ran at around 75°C, and over time I gradually reduced that through 70, 65, 60, 55 and eventually around 45°C. That experiment taught me a lot about how the house behaved at lower water temperatures, which rooms struggled first, and how ready the heating system was for a future heat pump. I also cover: • Flow temperature vs return temperature • Why a 90% efficiency badge does not mean your boiler always runs at 90% • Why lukewarm radiators are not necessarily a problem • Why longer, steadier heating can work better than short blasts of very hot water • Why you should test lower flow temperatures when it is properly cold outside • Weather compensation • Combi boiler hot-water temperature • Using lower flow temperatures as a simple heat-pump readiness test Let me know in the comments what flow temperature are you running now, if you have successfully lowered your flow temperatures and what difference it made to your gas consumption. #Boiler #CombiBoiler #energysavingtips 📊 Real-world UK energy data, analysis and tools: 👉 https://energy-stats.uk 🔥 Need help choosing a trusted heat pump installer? 👉 https://trustedheatpumpinstallers.co.uk/ ⚡ Switch to Octopus Energy (we both get £50): 👉 https://mickwall.octopus.energy/ 🎙️ Energy Unwrapped Podcast: 👉 https://energy-stats.uk/energy-unwrap... ➤ What is Boiler Modulation and Boiler Cycling? 🔗‍️ https://www.heatgeek.com/articles/wha... ➤ Hot Water Temperature - Scalding and Legionella 🔗‍️ https://www.heatgeek.com/articles/hot... ➤ Heating Hub Boiler Controls Article 🔗‍️ https://www.theheatinghub.co.uk/artic... ➤ SPF Calculator (Heating Cost Calculator) 🔗‍️ https://energy-stats.uk/heating-cost-... ➤ Heat Loss Survey Tool 🔗‍️ https://energy-stats.uk/free-heat-los... ➤ Get vidIQ to grow your channel faster! 🚀 🔗‍️ https://vidiq.com/mickwall CHAPTERS 0:00 The Boiler Flow Temperature Mystery 1:22 Boiler Controls vs Room Thermostats 2:08 Flow vs Return: The Heating Loop 3:14 Why Lukewarm Radiators Still Work 4:46 Is Your Boiler Actually 90% Efficient? 6:09 Turning Efficiency Into Pounds and Pence 9:17 How to Start Your Own Boiler Experiment 10:36 Lessons From My Own Home Test 12:04 Why Cold Weather Is the Real Test 13:13 The Role of Weather Compensation 14:56 The Heat Pump Readiness Test 15:42 Summarizing the Benefits of the Experiment