With increasing costs of energy around the UK, most homeowners want efficient means to help save money while not compromising comfort. Your boiler can be the answer to this problem. You’d be surprised to learn that merely changing your simple boiler temperature options can save as much as £65 per annum with your home still remaining equally warm. This minor shift merely lasts less than five minutes but can cut back on your energy use and carbon impact noticeably.
As energy grant experts, we’ve assisted numerous UK homeowners in optimizing their heating efficiency by utilizing government funding for energy-efficient upgrades. Fill in our form to check your eligibility for free ECO4 heating system upgrades. In this blog, we’ll outline precisely what boiler temperature you should use to achieve the best performance, why it’s so important, and how altering your settings might qualify you for more funding.
Understanding Your Boiler Temperature Settings
Before we dive into some specific temperature recommendations, let’s learn about what we are actually working with and how your boiler system works. Your flow temperature is the temperature of water exiting your boiler to travel to your radiators. It is different from the temperature you turn on your room thermostat. At the initial installation of your boiler, the flow temperature will typically be around 75°C to 80°C, higher than it should be for most homes and can stop your boiler from running at its optimal efficiency.
Most UK residents are unaware that this is a setting which can be changed directly on the boiler itself, independent of your thermostat controls. Your thermostat determines when your heating is on or off in order to attain the desired room temperature, but the flow temperature determines just how hot the water is prior to it being circulated through your radiators.
Newer boilers will usually have a variety of temperature controls:
- Central heating flow temperature – Regulates how hot the water is before it is supplied to your radiators
- Hot water temperature – Regulates the temperature of your tap water, found on combi boilers.
- Room thermostat – Not on the boiler itself, but regulates when the heating is on
All three have a specific purpose, and knowing the difference is crucial in order to get the best out of your system.
How Temperature Settings Affect Energy Efficiency
Your boiler efficiency is all in the temperature settings. That is because modern condensing boilers are designed to recover heat from flue gases that would otherwise be lost. The process of capture is optimized when the return temperature on your boiler, when the water coming back from your radiators, is low enough that water vapor in the exhaust can condense and give off more heat that can be recovered.
If your flow temperature is set higher than it should be, then so too is your return temperature, and the lower the condensation and the lower the heat recovered. By reducing your flow temperature, you allow your boiler to run in condensing mode more often, recovering more heat and burning less gas to provide the same amount of warmth in your home.
Optimal Central Heating Temperature Levels
Evidence from several authorities like the Salford Energy House indicates that the optimum flow temperature for most UK combi boilers is around 60°C. This is a marked drop from factory settings of 75°C-80°C used by most installers.
By reducing your flow temperature from 80°C to 60°C, you might reduce your gas consumption by up to 9%. Reducing it further to 55°C might save up to 12%, but this is only worth doing for well-insulated homes and may increase the heating time. For the elderly and individuals with pre-existing health conditions that put them at risk of catching cold, it is advisable not to decrease the flow temperature below 60°C to allow your home to warm up within a reasonable time.
Recommended Hot Water Temperature
For your hot water, especially if you’ve got a combi boiler or a system with a cylinder, the best temperature is between 50°C to 60°C. Keeping your hot water temperature at about 60°C offers the most ideal compromise of safety, comfort, and efficiency Check your eligibility for a new A-rated combi boiler by filling in our form.
Avoid reducing the temperature of your hot water below 60°C if you have a hot water cylinder since temperatures below 60°C raise the risk of Legionnaires’ disease, an infection caused by Legionella bacteria that develop in warm water. It is generally known that if you’re constantly mixing cold with hot when showering or using taps, your hot water temperature is too high and can be adjusted downwards to save energy.
Seasonal Boiler Setting Adjustments
Another often neglected boiler efficiency detail is adjusting the setting seasonally. In winter you should have a 60°C to 70°C flow temperature while in Spring and Autumn a 50°C to 55°C flow temperature will suffice. By setting these seasonal adjustments, you are able to achieve maximum efficiency over the course of a year without compromising comfort compared to the outdoor temperature.
Understanding the Science Behind Temperature Settings
To truly understand why temperature settings matter, let’s discuss the science behind the operation of modern condensing boilers. Condensing boilers are a great technological advancement in heating systems from traditional old-fashioned boilers. They have a second or higher heat exchanger, which is used to extract more heat from the flue gases before they exit through the flue. This is one of the reasons they are the most popular heating system in the UK, and why they are covered fully by the ECO4 scheme.
In an ordinary boiler, these flue gases would be released, resulting in wasting useful heat energy. In a condensing boiler, though, the gases are taken down to the temperature level at which water vapor forms droplets again and releases latent heat in doing so. This is utilized and tapped to reheat the returning cold water from your radiators.
The Condensing Effect and Temperature Settings
In order for condensation to be effective, the return water temperature entering the boiler should be below the flue gas dew point. If your flow temperature is 80°C, your return temperature will likely be too high for effective condensation to occur, and therefore your boiler will essentially operate like a standard boiler and not like a high-efficiency condensing boiler.
If you lower the flow temperature to about 60°C, the return temperature will usually be low enough for proper condensation, enabling your boiler to recover that extra heat and run at its rated efficiency, usually more than 90% compared to older non-condensing boilers that may run at 70-80% efficiency. This concentrated water, which is very slightly acidic with dissolved carbon dioxide from combustion, is carried away harmlessly by so-called condensate pipes. ECO Boiler Grants ensures that you only get the best boilers on the market by working with reliable brands like Worcester Bosch. Their reliability and extended warranty enables you to sit back and relax comfortably in your warmer home without having to worry about cold drafts or constant breakdowns.
What is Best For Your Home?
Each home is different, and issues like insulation quality, radiator sizes, and personal comfort levels will determine what ideal temperature settings for your situation will be. Getting your boiler to its optimum settings can take some experimentation.
A sensible strategy is to begin by lowering your flow temperature to 60°C and see what effect that has on your home over a couple of days. If your home warms up adequately and remains comfortable, you might then try lowering it further to 55°C to find out if more savings can be made without loss of comfort.
Remember that lower flow temperatures mean your radiators won’t feel as scorching to the touch as they might have previously – this is normal and doesn’t mean your heating system isn’t working properly. What matters is that your rooms reach and maintain your desired temperature.
Grants and Funding for Boiler Efficiency
As an advisor for energy grants, we’d like you to know about all the funding available to help you boost your heating efficiency.
The Energy Company Obligation (ECO4) scheme represents a significant opportunity for UK homeowners to enhance their energy efficiency and reduce their carbon footprint. ECO4, which runs from April 2022 to March 2026, is the latest initiative of the government’s commitment to tackling fuel poverty and promoting sustainable living. With a substantial £4 billion in funding, this scheme aims to deliver energy efficiency and heating measures to homes throughout Great Britain, focusing particularly on the vulnerable and those most in need.
One of the most compelling aspects of ECO4 is its emphasis on supporting households with the lowest incomes. Eligibility extends to those receiving means-tested benefits, but importantly, up to 50% of the obligation target can be met under the LA Flex scheme. This flexibility allows us to reach households on low incomes who may not be in receipt of benefits, potentially benefiting many more households.
For homeowners, the scheme offers a range of fully funded grants to improve home heating efficiency. These grants cover various measures, including gas boiler upgrades, air source heat pumps, and insulation measures such as loft, cavity wall, and internal wall insulation. It’s worth noting that only homes with energy efficiency bands D-G are eligible for ECO4, ensuring that the scheme targets properties that need the most improvement.
A key feature of ECO4 is its ‘whole-house’ approach to energy efficiency. This means that rather than implementing isolated measures, the scheme aims to comprehensively improve a property’s overall energy performance. In fact, to qualify for the grant, the measures installed must improve the property’s efficiency rating by at least two SAP bands, to a D rating or higher.
As an energy grant provider, we’re particularly excited about the potential for ECO4 to drive the adoption of renewable technologies. While solar panels are included in the scheme, they’re primarily available for properties where the primary heating source is electric. This aligns with the broader goal of reducing reliance on fossil fuels and promoting cleaner energy solutions, such as heat pumps, which get free solar panel installations. Fill in our form in less than 45 seconds to check your eligibility, and to understand where you stand and what to do next.
Conclusion
Adjusting your boiler temperature settings is one of the easiest and most efficient ways of increasing your heating efficiency, lowering your bills, and lowering your carbon footprint. By dropping your flow temperature to approximately 60°C, you can cut your gas bills by up to 9% and still maintain a comfortable room temperature.
Keep in mind that the optimum temperature settings will vary depending on your specific situation, such as your type of property, levels of insulation, and personal comfort. Finding the ideal mix for your dwelling might take some trial and error, but the potential savings make it well worth it.
In addition to the tuning of your boiler controls, also take a look at available grants and finance options for large-scale energy efficiency modernizations. Your home heating could become more not only efficient, but also more future-proof under the ECO4 and Boiler Upgrade Scheme.
