4 Reasons Why Your Shower Drain Smells?

Shower drains may begin to smell because of many common reasons. It’s likely the mould or mildew is developing under your drain cover. Your p-trap is likely faulty, causing sewage gas to rise into your pipes. Or that hair or grime has likely got caught in your shower drain strainer.

Fortunately, most of the problems that are causing your shower drain to stink are easy to fix. We’ve mentioned the most possible sources of your stinky problem below, whether your drain smells like mildew or Sulphur. You should be able to spot and delete them with ease if you follow these tips.

  1. Clogged Strainer Or Stopper

Any shower drain has a strainer or stopper installed into or over it. Hair, soap scum, and other debris are trapped in these fixtures before they run down the drain. All of the gunk and grime that your strainer or stopper collects can begin to accumulate over time. Many shower drain odours are caused by aging, buildup debris and shower drainage intercepted by your strainer or stopper on the way down your drain.

You should be able to pull out the stopper by hand. A single screw in the strainer must be inserted using a simple screwdriver. Once you remove the strainer, you’ll probably find a buildup of hair, scum, and grease. Put on some gloves and clean the strainer with thick, soapy water, a sponge, or a bristle brush, or an old toothbrush. You can also wipe off any debris that has been collected on the drainpipe where the strainer was removed.

  1. Mould or mildew growth

Mould and mildew flourish in cool, damp conditions. It will expand anywhere within your shower if given the chance. Check to see that the strainer/stopper is appropriately seated before removing it. While you’re at it, double-check that the drain cover is fully secured as well. If there is some gap between the drain cover and the pipe, or between the strainer and the tub, mould or mildew may flourish.

The drain cover and stopper should be removed and washed with a mould and mildew removal solution. Make sure to spray and disinfect the drain’s underside as well as the ring surrounding it. When you’re done, double-check that your drain cover fits snugly over the drain. If you can’t get it to stay straight, it’s bent and has to be fixed right away.

  1. Dry p-trap

The curving part of the drainpipe that attaches a fixture’s drain to the rest of your drain system is known as a “p-trap.” It’s known as a “p-trap” because it bends in a p or u shape. P-traps are built to capture and retain a portion of the water that drains into them, which is why they curve this way. This water helps to prevent any sewer fumes from floating up into the pipes and allowing you to smell them.

Your p-trap may not be doing its job if you smell sewage gases or rotten smells. Take the strainer from the drain and shine a spotlight down it. If there is no water in the pit, something is likely wrong with it. Wait an hour after dumping two cups of water down the pipe. Try calling an expert if the water isn’t there in an hour. Alternatively, you might dump four ounces of cooking oil down the drain with the water. The oil would likely block the water from evaporating.

  1. Clogged or blocked vents

The water you’re attempting to reintroduce into your p-trap is likely disappearing because your shower vents are blocked. The air forced out by the arrival of water has somewhere to go due to pipe venting. Suction within your pipes could siphon water out of your trip if you don’t have it. Vents usually attach to the trap and then to an outlet known as a “vent stack.” There is a vent on any pipe that leads to the vent stack.

The vent stack is where the bulk of clogs exist. A bird’s nest could be near the stack’s entrance, or debris could have fallen into the vent itself. You might try to clear your vent stack’s outlet yourself if you know where it is and can access it safely. Remove everything from the vent’s mouth first. If there’s nothing obvious, the problem could be deeper inside. Try flipping on a hose and running it down the stack’s vent. The water pressure can assist in clearing the vent system.


Don’t get frustrated if none of these tips doesn’t work. There’s probably always a simple and straightforward approach. It’s likely that one of your pipe vents is blocked, or that you have a sewage problem.

You can rely on SWR Plumbing to find and repair whatever is causing the odour. If you think you’re smelling something you shouldn’t, give us a call. We have yet to find a stench that we couldn’t remove.