Fix noisy radiators and pipes — HomeGraft

Bleed trapped air, secure loose pipe clips and insulate pipes to stop radiators banging, clicking or gurgling for good.

RD-01Get ready and stay safeTurn the heating off and let radiators cool before you start. Find your stopcock, usually under the kitchen sink, and check it turns freely so you can shut the water off fast if you ever hit a pipe. Lay down an old towel and have a bowl ready to catch drips.

1 each · Radiator bleed key

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1 each · Old towel or rags

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1 each · Small bowl or tub

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RD-02Work out what kind of noise you've gotA gurgle or hiss as a radiator warms up is trapped air - bleed it. A bang or tick along a wall or floor as pipes heat up is usually a loose pipe clip or a pipe rubbing on timber - this needs refixing, not bleeding. A loud kettle-like rumble from the boiler itself means limescale or a fault inside the appliance.

RULES

KNOW THE RULES

Only a Gas Safe registered engineer may work on a gas boiler or its gas pipework, by law. Do not open the boiler casing yourself.

RD-03Bleed each radiatorRun the heating until radiators are warm, then switch it off. Starting with the radiator furthest from the boiler, hold a cloth under the bleed valve and turn it slowly with the key until you hear air hiss out. Close the valve the moment water dribbles out steadily. Repeat on any radiator that feels cooler at the top than the bottom.

1 each · Cloth

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RD-04Check the system pressureIf you have a combi boiler with a pressure gauge, check it reads between 1 and 1.5 bar after bleeding - bleeding always drops the pressure slightly. Top it up using the filling loop if it's low, following your boiler's own instructions. If you're not confident doing this, leave it to a heating engineer.

RD-05Trace a banging pipe to its sourceFollow the noisy pipe run by hand while the heating is on, feeling for the point where it touches a wall, floor or joist without a clip, or where an old clip has snapped or worked loose. Expanding pipes knocking against bare timber or brickwork is the most common cause of banging.

RD-06Check what you're fixing into before you drillRun a stud detector or a strong magnet along the wall - a magnet pulls towards the screw heads fixing plasterboard to a timber or metal frame, so you can trace a stud line. A dull thud when you tap means solid brick or block behind; a hollow sound means stud or dot-and-dab. A small pilot hole that brings out fine wood dust means timber; grey metal swarf means a metal stud. Cables and pipes can run almost anywhere in a wall, not only in the usual safe zones, so use a cable and pipe detector too, and still treat the area as live until proven otherwise. If in any doubt, isolate the circuit at the consumer unit before drilling, and know how to shut the stopcock off before cutting into or drilling near anything that could carry water.

1 each · Cable, pipe and stud detector

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RD-07Refix a clip - solid brick or blockMark the clip's fixing hole on the wall. Drill with a 6mm masonry bit to a depth of 35mm, push in a matching wall plug, and screw the clip back on with a 40mm wood screw. The clip should hold the pipe firmly without crushing it.

1 each · 6mm masonry drill bit

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1 each · 6mm wall plug

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1 each · 40mm wood screw

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RD-08Refix a clip - plasterboard on timber studsFind the centre of the timber stud using the methods above. Drive a 40mm wood screw straight through the pipe clip into the middle of the stud. Never rely on a screw into plasterboard alone here - the pipe's movement will pull it straight back out.

1 each · 40mm wood screw

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RD-09Refix a clip - plasterboard on metal studsNever use a plain wood screw or plastic wall plug in a metal stud - it strips straight through 0.5mm steel. Use a self-drilling metal-stud fixing screw instead, which is normally enough for a light pipe clip. If there's no stud close enough, move to the plasterboard-between-studs method below.

1 each · Self-drilling metal-stud fixing screw

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RD-10Refix a clip - plasterboard between studsIf there's no stud nearby, use a small nylon toggle or hollow-wall anchor - a pipe clip is light, so a basic toggle rated for a few kilograms is enough. Drill a hole sized to the toggle, push the folded toggle through, then tighten the screw until it grips against the back of the board.

1 each · Nylon toggle fixing

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RD-11Refix a clip - dot-and-dab plasterboardDot-and-dab has an air gap behind the plasterboard before you reach the masonry. Use a fixing long enough to pass through the board, cross the gap, and still bite at least 30mm into the masonry behind - typically 60-75mm overall. Check the gap depth first with a bradawl test hole.

1 each · 60-75mm masonry fixing for dot-and-dab

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RD-12Refix a clip - lath and plasterLath and plaster is old timber strips under plaster, and it's often crumbly. Find a solid lath or the joist behind it with your detector, drill a small pilot hole, then use a longer screw that reaches solid timber behind the plaster. Don't rely on the plaster alone - it will crack and the clip will pull free.

1 each · 50mm wood screw

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RD-13Insulate the pipe to stop it happening againSlide foam pipe lagging over the pipe on both sides of the clip, leaving a small gap so the pipe can still move slightly as it heats up without touching bare timber or brick directly. Trim it to length with a craft knife.

1 each · Foam pipe insulation, 15mm x 1m

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1 each · Craft knife

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RD-14Test and tidy upTurn the heating back on and listen through a full heating cycle to check the radiator and pipe run are quiet. Wipe down your tools, sweep up any dust or swarf, and bin old screws or broken clips. Check the pressure gauge once more if your boiler has one.

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