Why Your Drains Smell Bad (And What To Do)
Water and other waste go down drains, and normally, this is supposed to be a one-way process, with nothing coming back up. So when something does start coming out of your drains, like a bad smell, that’s a problem, and it’s not something you should ignore.
Fortunately, the causes for smells coming from drains, or even water itself, are not always going to be expensive problems with expensive repairs. There are a few things you can do for yourself to easily solve these problems.
We have the three most common causes for a smell coming from your plumbing. Let’s start with the one that toughest to address and work our way down from there.
If You Have Smelly Water
If the water itself is the culprit and you detect an odour every time you turn on a tap and let it run, you likely have a problem with your hot water system and bacteria.
A lot of bacteria need warmth and moisture to start infesting a space, and a water heater can sometimes be the perfect site for doing just that. When that happens, it affects the water in your home, and you can smell it.
Fortunately, you have an easy fix for this. Bacteria need warm water, but if it gets too hot, that can outright kill them. All you have to do is adjust the temperature of your water heater to something higher, along the lines of 55-60°C.
If You Have A Smelly Drain
If a smell is coming from your drain, this may simply be gas from a sewage line entering your home, which happens if you don’t have a “vapor barrier” set up in the part of your plumbing known as a p-trap.
The p-trap is the bend in your plumbing that’s just under your sink, and all it needs to function is some water.
If that water has dried out or gotten displaced by air pressure from water movement in other pipes of your home, you can easily fix it. Just get more water and pour it down the drain.
This is often the most common problem for smelly drains, so always try this first before resorting to more elaborate solutions.
If You Have Sewage Problems
Unfortunately, this is an area where you may need an expert, depending on the exact problem.
Sewage issues can be varied, and may be the result of blocked ventilation, 
or something far more serious, like a break in your sewage line.
The extensive nature of sewer-related plumbing in a home means that are many areas where a problem could form and not all of them are easy to reach or see.
In the event that a simple fix like restoring your vapor barrier doesn’t work, you need to inspect as much of your sewage and ventilation as you can.
If you can’t find the problem yourself, it’s time to bring in expert blocked drain plumbers to get a proper inspection.
