Hang a replacement radiator on a dot-and-dab plasterboard wall — HomeGraft

Drain and remove the old radiator, then safely hang and reconnect its replacement, checking for leaks before finishing.

RAD-01Set up and protect the areaLay a dust sheet under the radiator and along your route to the door in case you drip water. Get a bucket, old towels and a radiator bleed key ready before you start. Turn the heating off and let the system cool for at least an hour so the water inside isn't scalding.

1 each · Dust sheet

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1 each · Bucket

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1 each · Radiator bleed key

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RAD-02Isolate and drain the old radiatorClose the TRV and the lockshield valve at each end of the radiator, turning both fully clockwise. Put the bucket under the lockshield union, loosen the nut with an adjustable spanner and let the trapped water drain out. Open the bleed valve at the top to let air in, which speeds up the draining.

1 each · Adjustable spanner

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RAD-03Take down the old radiator and bracketsOnce it's empty, lift the radiator off its wall brackets and rest it on an old towel to finish draining. Undo the old brackets and note their height and spacing, since a new radiator may need different fixing points. Fill any old holes you won't be reusing with a bit of filler.

1 tube · Multi-purpose filler

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RAD-04Work out what your wall is made ofTap the wall: solid brick or block sounds dull all over, while plasterboard sounds hollow. Dot-and-dab plasterboard sounds hollow with a duller thud every so often, where the adhesive dabs sit behind it every 300-450mm. Run a stud detector or a strong magnet over the wall to find timber or metal studs, then drill a small pilot hole in a hidden spot: pale dust means plaster or masonry, shavings mean a timber stud, and bright metal swarf means a metal stud. Lath and plaster feels faintly ridged under your hand, with narrow lines every 25-30mm.

1 each · Stud detector

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1 each · Strong magnet

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RAD-05Mark and level the new bracket positionsHold the new radiator's brackets against the wall at the manufacturer's spacing, or measure from your old positions if the new radiator matches the old one's width. Use a spirit level to mark a true level line before marking the fixing points - even 5mm out over a radiator's width will look wrong once it's hung.

RAD-06Check for cables and pipes before you drillRun a cable and pipe detector over every mark before drilling, but don't trust it completely - detectors miss deep cables, cables in metal conduit, anything behind metal-backed plasterboard, and can be confused by a metal stud frame. 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 circuit at the consumer unit and turn the water off at the stopcock before you drill.

1 each · Cable and pipe detector

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RAD-07Fit the right fixings for your wallSolid brick or block: drill with a 7-8mm masonry bit to the plug's marked depth, fit the plug, and use a 50-75mm screw or bolt sized for the bracket. Dot-and-dab plasterboard: push a thin screwdriver through gently first to find the void behind the board (commonly 20-50mm), then drill through into the solid masonry and fit a long fixing - a 10mm frame fixing or resin anchor of 100-120mm - so it grips at least 40mm into the masonry, not just the dab. Timber stud: fix into the centre of a stud with a wood screw, or fit a timber noggin between studs first if no stud lines up. Metal stud: never use a plain wall plug or wood screw, as it strips straight through 0.5mm steel - fit a timber noggin between the studs using self-drilling metal-stud screws, then fix the bracket to the noggin, since a stud alone won't hold a radiator's weight. Lath and plaster: find the stud behind the laths the same way as a timber wall and fix a long screw into its centre, fitting a noggin if nothing lines up, as lath alone will crumble.

1 pack · Wall plugs (red/brown, mixed)

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4 each · Masonry screws 60mm

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4 each · Frame fixings 100mm

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4 each · Resin anchor sleeve

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1 length · Timber noggin (50x50mm batten)

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8 each · Self-drilling metal-stud screws

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4 each · Wood screws 50mm

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RAD-08Hang the radiator and check it's secureLift the radiator onto the brackets, giving it a slight lift-and-drop so it seats fully on the bracket lip. Check it's level with a spirit level and check it doesn't rock - a rocking radiator means a bracket isn't fixed solidly and needs redoing before you connect any pipework. Push and pull gently at the top corners to test the fixings first.

RAD-09Reconnect the valvesFit new fibre or rubber washers to the union connections if the old ones look worn or flattened. Hand-tighten the TRV and lockshield unions onto the radiator tails, then nip them up with an adjustable spanner - don't overtighten, as this can crack the union. Check the pipework lines up without straining against the radiator.

1 pack · Fibre washers

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RAD-10Bleed the radiator and check for leaksOpen both valves fully, then open the bleed valve with the key to let trapped air escape, closing it as soon as water runs steadily. Wipe every joint and union dry with kitchen roll, then check them again after five minutes - any damp patch means a leak that needs tightening or redoing.

1 roll · Kitchen roll

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RAD-11Run the heating and recheckTurn the heating on and let the radiator heat up fully. Feel across it for even heat - cold patches usually mean trapped air, so bleed it again if needed. Check every joint once more after 15-20 minutes, since some leaks only show once the system is hot and under pressure.

RAD-12Tidy upTurn the heating off, wipe down the radiator and skirting, and remove your dust sheets. Take the old radiator to a local recycling centre, as most accept them as scrap metal. Vacuum up any masonry or plaster dust and dispose of offcuts and old fixings.

1 pack · Bin bags

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