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Does Lowering Boiler Temperature Save Money? The Surprising Truth Unveiled

As experienced boiler installers and heating engineers, we understand homeowners always seek ways to reduce their energy bills.

One option that has been gaining traction is turning down the flow temperature of your boiler. But what does this mean, and is it a good idea?

This article will explore the concept of lowering the boiler’s flow temperature and uncover the surprising truth behind its potential for saving money.

Understanding the Boiler Thermostat and Flow Temperature

Before delving into the benefits of lowering the flow temperature, let’s first understand the role of the boiler thermostat.

The boiler thermostat is a control on your boiler that adjusts the flow temperature, which is the temperature of the water sent to the radiators.

When the water flows through the radiators, it cools down before returning to the boiler. This return temperature is crucial in determining the efficiency of your boiler.

It is widely known that all boilers operate more efficiently when the return temperature is low.

Lowering the flow temperature not only reduces the flow temperature itself but also lowers the return temperature.

This can result in significant energy savings and ultimately reduce your gas bills.

The Benefits of Lowering the Flow Temperature

There are several benefits to consider when it comes to turning down your boiler’s flow temperature:

Increased Energy Efficiency

Lowering the flow temperature allows your boiler to operate in what is known as “condensing mode” more frequently.

Condensing mode enables the boiler to recover previously lost heat through the flue.

When the flow temperature is 60°C or lower, the boiler can reach its highest efficiency potential and significantly reduce energy consumption.

Reduced Gas Bills

Lowering the flow temperature can lead to substantial savings on your gas bills.

Studies have shown that households can save around 9% in gas usage simply by dialing down the heating flow temperature on their condensing combi boilers.

This gas consumption reduction benefits your wallet and contributes to a greener environment by reducing carbon emissions.

A mains gas supply connected to a boiler

Improved Comfort and Control

Contrary to what some may think, lowering the flow temperature does not compromise comfort.

You can maintain a warm and cosy home with the right adjustments while benefiting from reduced energy consumption.

Additionally, modern boilers offer precise temperature control, allowing you to adjust the heat output according to your preferences.

How to Lower the Flow Temperature

Now that we understand the benefits let’s explore how you can lower the flow temperature of your boiler:

Check Your Boiler Type

Before making any adjustments, it is important to determine whether you have a condensing combi boiler.

This boiler type provides heating and hot water without needing a separate hot water cylinder. If your boiler was installed within the last 16 years, it is likely a condensing boiler.

You can also identify a condensing boiler by a white plastic pipe underneath.

A family discussing their home's hot water and heating needs

Adjusting the Flow Temperature

To lower the flow temperature, you will need to access the controls on the front of your boiler.

Please note that the control for adjusting the flow temperature is separate from your room thermostat.

The method of adjustment may vary depending on your boiler model. Here are a few common scenarios:

  • Dials: Many combi boilers have two dials, one for heating and one for hot water. Turn the dial for heating down gradually until you reach the desired lower flow temperature.
  • Some dials may have numbers, dashed lines, or a curved line of increasing thickness. Consult your boiler’s manual for specific instructions.
  • Digital Displays: Some boilers have digital displays that show the flow temperature. Use the relevant buttons or dial to decrease the flow temperature to your desired level.
  • Combination of Dial and Digital Display: For boilers with a combination of dial and digital display, follow the instructions in your manual to access the flow temperature setting. Reduce the temperature to the desired level

Finding the Optimal Temperature Setting

The correct temperature setting for your boiler depends on various factors such as the age of your home, insulation levels, and radiator size.

As a general guideline, most older homes can run their heating systems at around 60°C, while newer, well-insulated homes can go as low as 50-55°C.

It’s important to strike a balance between energy efficiency and maintaining a comfortable living environment.

However, it’s worth noting that lower flow temperatures result in longer heat-up times. If you have the heating programmed for limited periods, it may take longer to reach your desired temperature.

Keep this in mind and adjust your heating schedule accordingly.

Frequently Asked Questions

To address common queries and concerns, here are answers to some frequently asked questions:

Q: Will turning down the flow temperature affect my hot water?

A: No, turning down the flow temperature specifically refers to the heating system and does not impact the hot water temperature.

The flow temperature for hot water is separate and should be adjusted accordingly.

Q: What if I have a hot water cylinder?

A: If you have a hot water cylinder, the advice differs. Please refer to section 12 for specific guidance on adjusting the flow temperature in this scenario.

Q: Can I adjust the flow temperature through trial and error?

A: Yes, you can experiment with gradually lowering the flow temperature to find the optimal setting for your home. Monitor the comfort levels and adjust as needed.

It’s a good idea to consult your boiler’s manual or seek professional advice if unsure.

Q: What if I have a health condition?

A: If you have a health condition that requires a specific temperature for comfort and well-being, it is advisable to prioritize your health above energy savings.

Consult with a healthcare professional before making any adjustments to your heating system.


Lowering your boiler’s flow temperature can save you money on your energy bills while maintaining a comfortable living environment.

By allowing your boiler to operate more efficiently in condensing mode, you can reduce gas consumption and contribute to a greener future.

Remember to adjust the flow temperature gradually and find the optimal setting for your home’s specific needs.

If in doubt, consult your boiler’s manual or seek professional advice. Enjoy the benefits of lower energy bills and a more efficient heating system.

Disclosure: This post contains affiliate links, including Amazon Associate links, through which I earn from qualifying purchases at no extra cost to you. I only recommend products I genuinely believe in. Visit my Privacy Policy page for more information.