Top 3 Reasons for Stinky Drains and Smelly Water

No matter how well maintained your home’s pipes and drains are, mysterious smells can sneak up from your waste drains or water supply.

If you find your home is carrying a smell similar to that of rotten eggs, there are some common, and curable, culprits.

These are the three top reasons that a home develops stinky drains or smelly water:

1. Dried Out P-Traps

To determine if a waste pipe in your home is dried up, you can do an at home sniff-test to find the problem pipe.

Follow the smell throughout your home, and try to find the room in which the smell is the strongest.

Cover this drain with a plastic bag or plastic wrap, and let the room air out. If you come back in an hour and the smell has all but vanished, you’ve found the source of the smell.

P-traps are the u-shaped sections located on most pipes, which hold a small bit of water within. This water acts as a seal by not letting any sewer gas enter your home.

These p-traps can dry up for a variety of reasons, including: 

• Leakage
• Disuse
• Blockages, causing water to siphon out of the p-trap.

If the origin of a sewer gas smell is from a pipe that has not been used for an extended period, try running water through it for a couple of minutes.

This will refill the p-trap, and eliminate the risk of sewer gas entering your home through this pipe.

If the smell is from a commonly used drain, have a plumbing professional inspect the p-trap. The p-trap could be leaking or have a blockage that should be removed and repaired by a trained expert.

2. Your Home’s Water Heater

Even though a water heater may not have any actual issues, its interior may be the source of smelly water within a home. The inside of a water heater is the perfect area for bacteria to grow, as it is moist and dark.

When these bacteria interact with sulfur in the water and metal components of a water heater, the result is that foul, “rotten eggs” smell that enters your water supply.

Luckily, there are a couple of options to deal with this problem. You can clean the inside of your water heater with H2O2, also known as hydrogen peroxide. This chemical works to kill bacteria while keeping your water heater safe.

The other option is to replace the magnesium or aluminum based anode within your water heater. Bacteria feed off these metals, creating the foul smell. Instead, install an anode made of both aluminum and zinc.

3. A Blocked Sewer Gas Vent

Most homes are equipped with a ventilation system dedicated to removing smelly sewer gases into the outside air.

If this ventilation system becomes blocked, sewer gases build up and enter waste pipes in your home, such as drains and toilets.

Common causes of clogged vents include:

• Debris
• Leaves
• Animal nests

Clear away any visible blockages, only if it is safe for you to do so.

If it is not a safe option, or you’re still detecting a foul odor from your waste pipes, contact a plumber immediately.