how to box in a boiler

How To Box in a Boiler in 6 Easy Steps (DIY Guide and Pro Tips)

Is an exposed boiler spoiling the look of your kitchen? You’re not alone. Research has found unattractive exposed boilers are a major bugbear among UK homeowners. A whopping 57% would want £5,000 off the house price just because the boiler was on show!

Fortunately, you don’t have to grin and bear it by living with an unsightly boiler. We’ll take you step-by-step through 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 a cupboard yourself.

Our instructions focus on the unit option, but most steps apply to building 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 measure your boiler accurately, as you need to find the right unit 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 around the boiler for ventilation.

Pro Tip: Dig out the manufacturer’s instructions for your boiler before measuring anything. 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 houses the boiler properly. To assess these alterations, first, take off the doors. You can then offer it up to 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

Cut the various notches and openings you’ve identified using a jigsaw. 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

Fit at least four angle brackets to your unit. The best place to put them is on the underside of the unit’s top and the inner surface of its base, as you’ll distribute the unit’s weight 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 need an extra pair of hands from here on. Get someone to position the unit in its correct location and use a spirit level to ensure the unit is level and stands flush with 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. The size of the plugs will 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 you screw the unit in place. You can 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 cupboard, you might want to consider decorating it. This Little House on the Corner post offers great tips for painting wooden furniture.

For more creative/thrifty ideas for your boiler boxing, check out the video below from the Carpenter’s Daughter:

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Also, If you’re feeling inspired, you may consider 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 comprises 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!

Pro Tip: check out our guide to boxing in pipes for tips on concealing pipework.