Fit a carbon monoxide alarm to a solid brick or block wall

Fit a carbon monoxide alarm to a solid brick or block wall, checked and screwed in safely.

AB-01Choose the right spot on the wallCheck the alarm's instructions for the recommended distance from any fuel-burning appliance, usually between 1m and 3m. Fit it at head height on a wall, not in a corner, and away from doors, windows or extractor fans where draughts can affect it. Avoid steamy spots like right next to a kettle or shower wall.

RULES

KNOW THE RULES

Building Regulations Part J (England) require a carbon monoxide alarm to be fitted whenever you install a new fixed combustion appliance, except a gas cooker. This applies to installing an appliance, not just fitting an alarm on its own - check if it applies to your job, and note Scotland and Wales have their own rules.

AB-02Gather your tools and materialsGet everything ready before you start so you're not hunting for a drill bit halfway through. Check the alarm comes with its own screws and plugs - if not, buy standard ones to suit a solid wall.

1 each · Carbon monoxide alarm

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1 each · Cordless drill

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1 each · 6mm masonry drill bit

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2 each · Wall plugs (6mm, red)

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2 each · Screws (30mm)

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1 each · Pencil

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1 each · Spirit level

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1 each · Dust sheet

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AB-03Mark the fixing holesHold the alarm's backplate against the wall at your chosen height and use the spirit level to get it straight. Mark through the two fixing holes in the backplate with a pencil, then double-check the marks are level with each other.

AB-04Check for cables and pipes, and find your stopcock, before you drillRun a cable and pipe detector over both pencil marks before you drill anything. Detectors can miss cables that are deep, in metal conduit, or just outside their range, so still drill carefully and be ready to stop the moment you feel resistance or see dust that looks wrong. Find your stopcock now, usually under the kitchen sink, and check it turns freely so you can shut the water off fast if you hit a pipe. If you have any doubt at all, isolate the relevant circuit at the consumer unit before drilling.

1 each · Cable and pipe detector

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AB-05Drill the fixing holes into the brick or blockUse a 6mm masonry bit to suit standard plugs, checking the plug packet for the exact size. Drill each hole about 45mm deep, keeping the drill level and going slowly so you don't crack the brick face. If a hole lands on a mortar joint rather than solid brick, shift it slightly rather than drilling deeper into the soft joint.

AB-06Fit the wall plugs and screw on the backplatePush a wall plug fully into each hole until it's flush with the wall surface. Hold the backplate up against your marks and drive a screw through each fixing hole into the plugs, using a screwdriver or a drill on slow speed. Stop tightening once the backplate sits snug - overtightening can crack the plug and loosen the fixing.

AB-07Fit the batteriesMost CO alarms run on batteries, either a standard 9V or a sealed unit built to last around 10 years. Fit the batteries following the manufacturer's instructions, matching the polarity markings inside the battery compartment.

1 each · 9V alarm battery (if not sealed unit)

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AB-08Attach the alarm and test itTwist or click the alarm body onto the backplate until it locks in place. Press and hold the test button, and check you get both the sound and any indicator light the manufacturer describes. If nothing happens, check the batteries are seated correctly before trying again.

AB-09Tidy up and note the expiry dateVacuum any brick dust off the floor, skirting and windowsill, and wipe the wall down. Check the alarm's expiry date, often printed on the back, and write it on a calendar or reminder so you replace it in time. Test the alarm monthly from now on.

1 each · Vacuum cleaner

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