Can You Mix Aluminium & Steel Radiators?

close up of person adjusting the thermostat on a radiator

Steel radiators are one of the most common types of radiator that we see in people’s homes, and are known for having good heat conduction periods, and being able to maintain their warmth for long periods of time. Aluminium radiators however, are excellent conductors of heat, heating up and cooling down a lot more quickly whilst running more efficiently. Both have their own pros and cons, but the real question is can you mix aluminium and steel radiators?

The short answer to this question is “no, not really”. Whilst technically, you can combine steel and aluminium radiators in your home, this is highly inefficient, and definitely not the most cost-effective choice. The main reason for this is that steel requires the water to be heated to a much higher temperature than aluminium radiators do. This means that combining the two will make the system completely inefficient, undermining the usual energy efficiency of the aluminium. In addition to this, steel prefers a more alkaline water, whilst aluminium doesn’t. This can cause aluminium radiators to corrode. 

Now we’ve established that the answer to the question of “can you mix aluminium and steel radiators” is a “no”, the next question is which type should you choose?

Aluminium Vs Steel Radiators – Which Should I Choose?

In order to help you decide which type of radiator system is best for your home, it’s important to know the pros and cons of each. 

Steel Radiators


  • Better heat conductors than cast iron 
  • Stay hot for longer, even when the heating system has been turned off
  • Durable & easy to clean


  • They require the water to be heated to a high temperature (usually between 70-80 °C)
  • Can be expensive to buy, particularly stainless steel
  • Take longer to heat up and cool down than aluminium

steel radiator fitted in front of a white wall

Aluminium Radiators


  • More energy efficient & better for the planet– water only needs to be heated to 30-50°C
  • They create an even distribution of heat throughout the home
  • They encourage a healthier indoor air quality (don’t create hot and cold spots like traditional radiators)


  • Upfront costs can be slightly more expensive (although offset by lower running bills)
  • As aluminium radiators are newer to the market, there may be slightly less design choice

person touching an aluminium radiator to see if it is hot

Steel may be  a more familiar sight to us, however aluminium radiators are becoming increasingly popular due to their many benefits, namely their high levels of energy efficiency, and pleasant heat distribution for the home. 

When answering the question of “can you mix aluminium and steel radiators”, we emphasised that steel requires the water to be heated to a much higher temperature than aluminium. This is one of the key reasons that they lack efficiency and cost-effectiveness, particularly when fuelled by a traditional boiler.

The most efficient way to power your radiators (steel or aluminium) is by using an air to water heat pump, rather than a traditional boiler. Rather than relying on fossil fuels, an air to water heat pump extracts heat from the outside air and transfers it into usable heat for the home. Leading the way in renewable heating solutions, a heat pump could enable you to cut your annual energy bills by more than half. The air to water heat pump is most effective when used with underfloor heating or aluminium radiators – These are our recommended solutions to maximise the cost-saving and environmental benefits of the heat pump system. 

For more guidance on upgrading your home heating system, please don’t hesitate to get in touch with us. Equally, if you have any further questions regarding “can you mix aluminium and steel radiators”, our team are more than happy to answer any queries you might have.

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