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Do radiator covers block heat?

Person sitting on the floor with their back against a black radiator with a big smile across their face. The person has a mug of tea in one hand and their phone in the other hand, searching for an answer to the question 'Do radiator covers block heat?'.

If you’re thinking about covering a radiator, there are a few potential benefits, but it’s a sensible question to ask if radiator covers block heat. The answer is that it depends entirely on what type of radiator cover you buy, and what other elements you take into consideration.

This guide will show you what you need to think about to ensure that you buy a radiator cover that does the job without trapping heat or increasing your energy bills.

Table of contents

  1. How do radiators work?
  2. So without a foil heat reflector, I’m losing heat?
  3. What’s the point of radiator covers?
  4. What is the disadvantage of radiator covers?
  5. Can radiator covers improve efficiency?
  6. What heat loss can I expect from a radiator cover?
  7. How much spacing needs to be between the radiator and the cover?
  8. Are radiator covers safe?
  9. Radiator Cover FAQs

How do radiators work?

First, let’s quickly outline how radiators work, so it’ll be easier to understand why some radiator covers might throw a spanner in the works.

Radiators should probably be called ‘convectors’ because the main way they move heat around a room is through convection. The convection happens when air warmed between the fins of the radiator rises to your ceiling and gets pushed around the room in a circle; i.e. circulates. Radiators do a tiny bit of radiating, but convecting is their main jam.

This is a crucial reason why radiators need some type of heat-reflecting foil backing to make the most of the heat you’re generating with your boiler and central heating system.

Rather than all that lovely warm air going up to the ceiling and into the walls, heat reflectors allow the heat to be pushed into the room.

Radiators also need to be checked often for cold spots and air bubbles. A new or old radiator may be cold at the bottom, which means it may have an air bubble and needs to be bled. Read more on how to bleed a radiator with our step-by-step guide, or if you’re still having trouble and need to figure out why your radiator is cold we’ve got more info to help.

So without a foil heat reflector, I’m losing heat?

Yes. Radiator cover or no radiator cover; without a heat reflector, you’re losing heat to the ceiling and the exterior walls, which could be pushed back into the room.

What’s the point of radiator covers?

OK. Let’s look at what the benefits of radiator covers might be:

1. Reclaim lost space

Your radiators keep you toasty and warm, but they might also be taking up valuable square footage. And if you’re an urban dweller, space comes at a premium. A tastily arranged radiator cover can help you reclaim the flat surface on top to display books, picture frames or hardy plants.

2. Childproof your home

If you have a family, there’s a certain period in your life when you have tiny humans barrelling around the house scraping, burning and generally injuring themselves. A hot radiator in an inopportune place can lead to a dangerous situation. Some parents like to surround their radiators with safety gates, although these could potentially be scaled by a particularly determined child or pet, so a radiator cover can help you neatly contain the danger and make sure no one gets hurt. It’s also worth noting that if a radiator begins to malfunction and starts spewing steam or hot water, a cover can help contain the problem until you’re able to get it fixed.

3. Reduce noise

Yep. Old radiators can be a little noisy. Covers can help turn the volume down on those hisses, pops and gurgles. Do make sure you’ve bled your radiators, though!

4. Beautify a room

Hey, old cast iron radiators aren’t perfect. Like all of us, they can lose their looks over time. You could refinish, but a radiator cover is the alternative low-cost way to spruce up a room. You can choose designs from metal to wood that blend in with your living space’s overall vibe.

What is the disadvantage of radiator covers?

In a nutshell, poorly designed radiator covers can cause heat loss. Anything that blocks a radiator’s airflow reduces its efficiency. Some radiator covers can actually trap heat and affect your thermostatic radiator valve (TRV) reading – confusing your entire central heating system. This is because if the TRV valve is encased within the cover, it may read a temperature that’s too high, because the space inside the cover is warmer than the rest of the room. Bad news.

Can radiator covers improve efficiency?

Yes. The good news is that well-designed radiator covers leave plenty of space for the warm air to travel through. A radiator cover could actually even improve your heat efficiency if the cover includes a reflective foil backing, which we mentioned earlier.

Some experts even say with the right type of airflow going from bottom to top, a radiator cover could boost natural convection and *add* a few degrees of heat efficiency. So, when you’re buying a radiator cover, make sure you shop around and do your research!

What heat loss can I expect from a radiator cover?

If a radiator cover is added, the obstruction could impact how evenly warm air is convected round the room. There is a measurement for radiator efficiency (British Thermal Units or BTUs) but it’s hard to officially determine the exact amount of heat loss as radiator cover efficiency varies so greatly.

How much spacing needs to be between the radiator and the cover?

To look after your radiator’s efficiency, you need to make sure there’s enough spacing between the radiator and cover. It’s recommended that the radiator cover is larger than the radiator by at least:

  • 40mm in width
  • 30mm in height
  • 20mm in depth

This spacing allows for the heat coming off the radiator to make its way into the room despite the cover (and aided by the addition or inclusion of heat reflective backing foil).

Are radiator covers safe?

Yes. As long as you follow our advice to buy a well-designed radiator cover with plenty of space and built-in reflector panels. That way you’ll not only be improving your heating efficiency and reducing your energy bill, but you’ll be protecting stray toddlers, and potentially making a tidy style statement too.

If you think you need professional assistance with your radiators boiler or pipes, contact HomeServe for assistance.

Radiator Cover FAQs

How much heat do you lose with a radiator cover?

A well-designed cover with built-in reflective panels and well thought out airflow (from bottom to top) could actually aid the radiator’s convection function and add a few degrees to your heat efficiency. A poorly designed one may not leave enough space, and could reduce your heat efficiency. So shop around and do your research.

What are the benefits of radiator covers?

A well-designed radiator cover can help you reclaim lost space, protect your family from the dangers of hot radiators, reduce noise and is a low-cost way to spruce up a room. Plus some well-designed radiator covers can even improve heat efficiency.

Is it safe to cover a radiator?

Yes. As long as you buy a well-designed radiator cover with plenty of space for heat to escape into the middle of the room (with the help of built-in reflector panels).

How to measure for a radiator cover?

To measure a radiator for a cover you’ll need a tape measure. Read our article on “How to measure a radiator” for a step by step guide.

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