Quick answer: Nine times out of ten it's one of two things. Either a water trap (the U-bend) has dried out and is letting sewer gas straight back into the room, or fat, grease, food and biofilm have coated the inside of the pipe and gone rancid. Running the water to refill the trap and cleaning out the build-up sorts most household smells for free. If the smell keeps coming back, that usually means a partial blockage further down that needs clearing properly. For a persistent sewer smell in Brighton or Hove, call Danny on 07404 434534.
Why does my drain smell?
A drain smells when sewer gas or rotting waste has found a way to your nose instead of staying sealed away. The usual suspects:
- A dried-out U-bend or trap. Every sink, basin, shower and toilet has a bend holding a small plug of water, and that water is the seal that stops sewer gas coming up. In a spare-room basin or a shower nobody uses, it slowly evaporates, the seal goes, and you get a sewage smell straight up the plughole.
- Fat, grease and food build-up. In kitchen drains this stuff clings to the pipe wall, turns rancid and smells. It's the most common cause of a bad-smelling kitchen sink by a distance.
- Biofilm, a slimy bacterial layer coating the inside of pipes and overflows, particularly in bathroom basins. Musty or eggy, and it can smell even while the water drains perfectly well.
- A partial blockage further down. Waste that's only half draining sits in the pipe and rots, and you'll usually notice slow draining alongside the smell.
- A blocked or restricted soil vent pipe. The vent lets drain gases escape above roof level. Block it with leaves or a bird's nest and those gases get pushed back through the traps inside the house instead.
- A dry or dirty outside gully, the grid outside where waste water discharges. Choked with silt, leaves and grease, it can stink out the whole back of the house.
One thing worth knowing locally: a lot of Brighton and Hove terraces sit on older, shared Victorian drainage. When one of those shared runs is partly blocked, the smell can turn up at two or three properties at once, and it keeps coming back until the run itself is cleared.
How do I get rid of drain smells?
Start with the free fixes. Most of the time you won't need us.
- Run the water. If it's a rarely used sink, bath or shower, run it for a minute to refill the trap. A jug of water down an unused plughole once a week keeps the seal topped up permanently.
- Clean the trap. Under most sinks the U-bend unscrews by hand or with a wrench. Bucket underneath, unscrew, pull out the hair, food and gunge. Unpleasant, but effective.
- Hot water and soda for grease. For a greasy kitchen drain, use a kettle of hot (not boiling) water followed by a good handful of soda crystals dissolved in hot water. Repeat weekly if your kitchen is prone to it.
- Clear the outside gully. Lift or scrub the grid and scoop out the silt, leaves and grease sitting in the trap, so waste water actually flows away instead of standing and rotting.
- Check the vent. If smells appear indoors every time an appliance drains, suspect the soil vent pipe. Leave that one to us. It's roof level and it isn't worth a ladder.
Don't get into the habit of tipping strong chemical cleaners down. They rarely touch the underlying build-up and they just sit there in a blocked pipe.
When does a smelly drain mean a blockage?
When it keeps returning after you've cleaned everything, or when it arrives with slow draining, gurgling, or water rising in the gully. Those mean waste is sitting and rotting in a pipe that's partly or fully blocked, and no amount of topping up traps will fix that. The pipe needs clearing.
We clear it at the source. Jetting is what really earns its keep here: it strips the fat and grease off the pipe wall rather than just punching a hole through it, which is why the smell tends to stay gone afterwards.
If you've got a smell that won't shift, book blocked drain clearance and we'll sort it. We cover Brighton, Hove and the surrounding Sussex area, 24/7.
Smell won't shift? Call 07404 434534 and we'll get it cleared.