how to box in a boiler

How to Box in a Boiler in 2022 (Step-by-Step DIY Guide and Top Tips) – UK Edition

Is an exposed boiler spoiling the look of your kitchen? You’re not alone. Research has found that unattractive exposed boilers are a bugbear among many UK homeowners.

In fact, 57% of them would look to knock £5,000 off the purchase price of a house just because the boiler was on show!

Fortunately, you don’t have to grin and bear it by living with an unsightly boiler. We’re going to take you step-by-step through the process of how to box in a boiler, transforming it from an eyesore into a feature.

Tools & Materials

house heating boiler


  • Tape measure
  • Carpenter’s pen
  • Jigsaw
  • Spirit level
  • Hammer drill
  • Screwdriver


  • Kitchen unit (or cupboard built from scratch)
  • Angle brackets
  • Countersunk screws
  • Spirit level
  • Masonry wall plugs (red plugs for 6mm holes should be sufficient)
  • Extra pair of hands

How to Box in a Boiler – Step-by-Step Instructions

building the boiler box

The easiest (and best) way to box in a boiler is by using a ready-made kitchen unit. Picking one to match your kitchen décor limits the amount of work you need to do.

You could also choose to build your own cupboard to do the job. Our instructions will focus on the unit option, but most of them still apply if you do choose to build a cupboard from scratch.

BTW, if you’re more of a visual learner, complement our instructions below on how to box in a boiler with this wonderful timelapse video from Patrick Henry:

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1. Measuring Your Boiler

Your first step is to accurately measure your boiler. You need to find the right unit you can use to box it in. When choosing the unit, there are a couple of important things to keep in mind:

  • The boiler must be easily accessible for servicing and/or repairs
  • You must leave at least 50mm of space all around the boiler for the purpose of ventilation

Pro Tip: Before measuring anything, dig out the manufacturer’s instructions for your boiler. Check if there are any specific requirements for ventilation or flue-ing.

2. Identifying Alterations

You’ll need to make a few alterations to your unit before it will house the boiler properly. To assess these alterations, first, take off the doors. You can then offer it up into its final position.

When you do that, the alterations will become obvious. Mark the positions on the unit where you need to cut notches or gaps to accommodate pipes, cables, thermostats and the like.

3. Making Alterations

Using a jigsaw, cut the various notches and openings you’ve just identified. You don’t want them to be too tightly fitted to the pipes or cables, but you also don’t want gaping gaps in the unit.

After making initial cuts, offer the unit back up into position. Assess whether you need to enlarge or alter any of your cuts. Take the unit back down and make the tweaks. Repeat the process until it fits snugly around the pipes and extrusions.

4. Attaching Brackets

You now need to fit brackets to your unit. You’ll want to fit at least four angle brackets. The best place to put them is on the underside of the unit’s top, and on the inner surface of its base. That way, you’ll distribute the weight of the unit evenly when putting it on the wall.

Use a spirit level to make sure your unit is level where it stands. Place the brackets into position and drill pilot holes. Then screw the brackets in place securely.

Pro Tip: You’ll be best served using countersunk screws to fix your brackets. That will ensure the screw heads don’t stick up above the level of the bracket. You can find more about countersinking, and screws in general, in our guide to picking the right screw for the job.

5. Preparing Your Wall

You’ll definitely need an extra pair of hands from here on. Get someone to position the unit in its correct location. Use a spirit level to make absolutely certain that the unit is level, and stands flush to the wall.

Use a pencil to mark the positions of the bracket holes on the wall. Take the unit down and then drill the holes in the relevant places.

Pro Tip: Your best option is to use a hammer drill to make your holes. Hammer drills are designed specifically for harder surfaces like brick, concrete and mortar. They work by delivering a succession of blows, as well as rotating.

6. Fixing the Unit

After drilling your holes, insert wall plugs (sometimes also called rawlplugs) into them. Which size plugs to use will obviously depend on the drill bit you used to drill your holes. The standard red plugs (for 6mm holes) should be fine.

Get your assistant (whether they’re glamorous or not is entirely up to you) to once again hold the unit in place. Take the same measures as before to ensure its level and flush before screwing the unit into place. You can then reattach the doors you took off earlier, checking that they hang straight and open properly.

7. (Optional) Finishing Touches

That could be the end of your project. If you’ve used a mismatched unit or made your own cupboard, though, you might want to think about decorating it. This post from Little House on the Corner offers some great tips about painting wooden furniture.

For more creative/thrifty ideas, check out this video from the Carpenter’s Daughter:

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Also, If you’re feeling inspired, you may also want to think about concealing other functional but unsightly elements in your home. Popular DIY blogger (and PWS author) Kezzabeth offers some great insights into the possibilities of hiding pipes behind skirting boards.

How to Box in a Boiler – Final Thoughts

That’s all there is to it. Our guide explaining how to box in a boiler is made up of just half a dozen simple steps. With a little time, effort and expense, you can solve one of the most common aesthetic issues of UK homes – and one which might be knocking £5,000 off your property’s value!