The Most Common Reasons for Stinky Drains and Smelly Water

If you’re coming across an unattractive odor of rotting eggs within your home, don’t look in the fridge. The more likely causes are your waste drains. This could be your kitchen sinks, your toilets, or your water supply.

There are four common reasons why your drains or water have become stinky. The good news is that such problems can all be quickly assessed and fixed with the help of a plumbing professional.

1. Dried-Up P-Traps Causing Stinky Smell

The Problem: A P-trap is a U-shaped part of a pipe, containing water which acts as a seal for the pipe.

This seal keeps sewer gas from entering the waste pipe and instead directs it to the ventilation system, allowing sewer gases to exit your home safely.

However, P-traps are known to dry up sometimes, for a variety of reasons including:

  • A leak in the pipe
  • Disuse of the waste drain - this causes the water to evaporate in the P trap and thus leaving it dry.
  • A blockage in the p-trap, siphoning water out of the pipe

If a P-trap dries up due to or not limited to any of the reasons above, then this will permit sewer gas that is found inside the waste pipes to leak out of the pipe and into our homes, causing that smelly odor that you are trying to get rid of.

Dry P Trap causing stinky smell

The Solution: For a dried-up P-trap in a pipe that has not been recently used, attempt to run the tap for a few minutes. This flow of water should refill the P-trap, and hopefully, will eliminate the smell of sewer gas and bacteria. You could also try directly pouring some water into the dried-up P-trap; however, the water will most probably dry up and evaporate, and you will have to repeat the process every time that this happens.

If the smell is coming from a pipe that is used often, you will want to check for more critical issues, such as a leak or blockage.

Our plumbing experts can help you locate the source of the smelly problem, and repair it before the issue becomes more critical and difficult to fix.

2. Water Heaters Causing Stinky Smell

The Problem: Your home’s water heater is the perfect environment in which bacteria can thrive and multiply. Being both dark and moist, bacteria can spread, creating a foul smell.

With the addition of sulfur from some water supplies and metal components within a water heater, the “rotten egg” smell becomes prominent and can spread through a home in its water.

Electrician fixing water heater causing stinky smell

The Solution: First, attempt to clean your water heater with H2O2 (hydrogen peroxide) Hydrogen peroxide helps to kill bacteria within your water heater without damaging its interior.

It is also safe for the environment, as hydrogen peroxide breaks down into oxygen and water components in time.

If that does not work, have a plumber look at the anode that is in your water heater. Bacteria feed off specific types of metal components in the water heater, including magnesium and aluminum.

Anodes are commonly made of one of these metals. Install an anode that has both zinc and aluminum components, as this may help to limit the number of bacteria within the heater.

To ensure that this problem does not recur, a water filtration system can be installed. These systems work to filter out excess sulfur from the water supply

3. Ventilation Problems Causing Stinky Smell

The Problem: In many homes, there is a ventilation system dedicated to removing dangerous and smelly sewer gases.

Blocked drain P Trap Causing Stinky Smell - hydrogen peroxide smelly drain

Since P-traps work to keep this gas from waste pipes, they instead enter this ventilation system, leading the gas up and out of a home.

However, these ventilation systems can become clogged for several reasons, including:

  • An excessive amount of snow
  • An animal’s nest
  • Debris
  • Leaves

The Solution: Clogs that are accessible or obvious can be removed by yourself, but only if safe. It is recommended to call a plumbing professional, who is equipped with the proper tools and experience to safely remove the clog.

4. Plumbing Errors Causing Stinky Smell

The Problem: Sometimes, general plumbing errors such as missing vents, traps, and leaks, as previously mentioned, can be the reason that your ventilation system is having issues in the first place. Smells coming from your bathroom or kitchen sink are all linked to plumbing errors, that cause ventilation problems as well as dried P-Traps. 

Plumbing errors causing stinky smell and ventilation problems

The Solution:

It is important to get your ventilation system checked up regularly, in order to ensure that there are no plumbing errors that are causing unwanted odors in your home. The last thing you want is multiple rotting drains that are left unserviced for a long period of time. Plumbing errors that are left unnoticed can create further damage, so it's important to get them checked as soon as you notice any unwanted smells.

Related: What Small Changes Can Make Plumbing Run Better?

Schedule an appointment with our experts here ar Safari Plumbing, and we'll get that stinky smell sorted for you in no time.