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What Temperature Should My Combi Boiler Be Set At?

What Does The Temperature Of Your Boiler Mean?

When we reference the temperature of your boiler, we are actually discussing the temperature of the boiler itself, not the level of a thermostat or target heating temperatures for rooms in your house. The most important thing to remember, is that these are unique - the boiler needs to heat to a specific temperature in order to heat the rest of your home, and that operation is defined by the thermostat you set for your home.

To make a comparison, a typical home thermostat is often set between 19-21 degrees celsius, whilst a boiler can be set anywhere upwards of 75 degrees celsius. Furthermore, a boiler will have a different temperature setting for use when heated water is required. Depending on the setting chosen, your central heating system's performance can change quite drastically, either through the speed at which your home will be heated, or in the efficiency of the heating process itself.

What Settings Should My Combi Boiler Have?

The exact temperature setting for a combi boiler is not set in stone, though there are some generally accepted guidelines for efficient operation and heating performance.

For a modern combi boiler, the radiator heating temperature should be set at or around 75 degrees celsius for the best efficiency and performance. In summer, you can consider reducing the boiler’s radiator temperature setting to around 65 degrees celsius, as this will provide additional efficiency at the cost of heating performance. As an additional note, this temperature setting refers to the temperature of the water inside the radiator while heating your home; if you have young children or anyone that may be sensitive to higher temperatures in your home, we recommend reducing the boiler temperature to the lower 65 degrees celsius at all times, or to use a radiator guard.

Meanwhile, we recommend the water heating temperature to be set at around 60 degrees celsius. Setting this any higher can increase the risk of scaling within your system, so is ill advised. This setting should again provide an ideal balance of heating performance and efficiency for the majority of homes..

How To Set Your Boiler Temperature

Adjusting the radiator and water temperature on a modern Vaillant combi boiler is quick and simple. Our modern boiler systems come equipped with a user control panel and LCD screen to facilitate adjusting the temperature, where individual settings can be input for your water and radiator temperature.

The actual process may vary depending on your specific model, so we recommend referring to your user manual for specific guidance. With that said, many of our systems will have a button for the radiator temperature and hot water temperature. Once pressed, you can increase or decrease the temperature in 1 degree celsius increments to your desired setting.

Tips For Efficient Heating of Your Home

To ensure you get the most efficient use of your home's heating system, there are a number of things you can do to get the most out of your boiler.

Lowering Your Thermostat in Your Home Can Greatly Improve Efficiency

Dropping the thermostat temperature within your home is one of the best ways to ensure your home heating is efficiently managed. Even just a difference of 1 degree celsius can have a large impact in your overall heating bills. Generally, anywhere between 19-21 degrees celsius should be comfortable for most homes.

Bedroom Temperatures Should Be Set Lower Than the Rest of the House

It’s highly recommended to ensure your bedroom thermostat temperature is set to a lower value than the rest of your home - typically by 2 degrees celsius. This is to ensure optimal sleeping conditions for most people.

As a note, if you do not have individual room thermostat functions, you can use a timer to increase the temperature during the day and reduce the temperature during the night in order to reach your desired settings.


Many people will not need to adjust their boiler temperature directly, though if you’re finding it takes too long to heat your home, the water is not at your desired temperature, or the radiators are uncomfortably warm when active, adjusting the boiler temperature itself can be the perfect solution.