Does Painting a Radiator Make it Less Efficient?

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Often, when it comes to renovating a house, radiators are a difficult feature to blend into our new scheme. Yet, without totally replacing the entire central heating system in your home, what can you do? Do you just leave the radiator there as is? Or is there something that you can do to help it fit in with the rest of your home's interiors?

One option is to paint a radiator to tie in with the rest of your scheme. But does painting radiators reduce efficiency? Here, we answer that question as well as identifying what paint for radiators is suitable for such a task.

Do radiator paint colours affect the efficiency?

Technically speaking, painting a radiator will affect its efficiency and efficacy. The reason being is that you are putting another layer - however thin - of insulation on top of its surface, affecting its ability to warm a room. However, the impact of that extra layer of insulation is going to be minimal because it is so thin that it should not affect its ability to draw air in and around the radiator to warm the room around it. That process relies on convection - how warm and cool airflow in a room - which the paint colour will not affect.

While some paint colours may arguably emit more heat, making them a little bit more effective when it comes to heating a room, a radiator's ability to heat space is not overly affected by this. If it keeps pumping out heat because hot water is running through it, it’s going to get hot from within and therefore warm the air around it, and consequently the room as a whole.

Can you paint radiators with normal paint?

In short, no. Painting radiators with normal wall paint may be tempting due to cost and ease, but in the long run it's not worth it. The reason being is that normal house paint is not manufactured to withstand the amount of heating and cooling that a radiator will subject it to. The result will be the paint constantly having to expand and contract which will damage the finish. You'll end up with cracks all over the radiator's surface making it look worse than when you started. Plus those cracks will attract dust which is hard to clean out once there. 

What paint for radiators is suitable?

So given that normal paint is a no go for painting a radiator, what paint for radiators is suitable for this purpose. And, what radiator paint colours are there available?

Well firstly, you could apply an undercoat to your radiator which can mean it is possible to use normal house paint. However, not only is this arduous, it is not always effective either. Plus, you have to do it on cast iron or steel radiators only. The undercoat you use must be a specialist radiator primer which means that the paint you apply on top will be able to stick or bind to the radiator's surface. Plus, it should stop rust from becoming an issue on your shiny new paint surface too. If you do not use a primer, you run the risk that the overall finish on your paint job will be patchy as well as drab if you choose a gloss finish.

Finally, when you have painted your radiator with a suitable primer, the paint you choose must be a paint that is able to take high heats. For example, a high heat enamel paint will work. Whichever heat durable paint you do choose, ensure that you paint your radiator in a couple of thin layers as opposed to one thick one. This will ensure that the efficiency of the radiator is not affected as much, plus it simply looks better too. Thick paint is subject to big blobs and dribbles which are highly unattractive.

Finally, the prep work involved in painting a radiator is key. Firstly, choose a colour from the outset that you know will work in your room and that you are happy with. There are so many available that it is easy to get overwhelmed. However, you need to do so much to a radiator before you start painting it to ensure a good finish - you don't want to get it wrong.

Those prep stages are cleaning it and priming it to an inch of its life. Priming it will also include sanding it and stripping it of any previous paint jobs. This is key not only to the finish of your radiator but also, again to ensure that it can emit heat as optimally as possible.

To paint your old radiator or invest in a new one?

Having read the process of how to paint your old radiator, you may well have decided to invest in a new one. Painted radiators can look great, but they are tricky to do well. Before you take the plunge and pick up a paintbrush, check out our range of affordable radiators today.


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