How to get rid of the bad smell from pipes
To get rid of the bad smell from pipes, you first need to know where it comes from. If it is a dry trap, simply running the tap will refill it. If it is grease or built-up residue, the trap and drain need cleaning. And if the smell persists, it may be caused by a blockage further along, a break, the network ventilation or a full septic tank, in which case an inspection or professional cleaning is needed.
Air fresheners or strong products only mask the smell for a few days. For it not to come back, the cause has to be removed.
In this guide we go through the most common causes, what you can do yourself and when it is worth calling a professional.
Why pipes smell bad: the most common causes
Dry trap
Every drain has a trap that holds a little water to block sewer gases. If a washbasin, shower or floor drain is not used for weeks, the water evaporates and the smell comes up through it.
Built-up grease and residue
Grease, soap, hair and food scraps stick to the trap and the pipe walls and decompose. This is the typical cause of smells in kitchen sinks and showers.
Partial blockage in the network
A blockage that still lets water through holds back waste that ferments. It usually comes with slow drains or gurgling. It may also be in a blocked manhole.
Ventilation problems
If the network is not properly vented, the traps are emptied when water flows down and the gases get into the home.
Breaks or open joints
A broken pipe or a displaced joint lets gases and wastewater escape. Sometimes the cause is roots that have got into the pipe.
Full septic tank
In homes with a septic tank, if it is saturated the smell appears in several drains at once. We explain it in how to stop a septic tank from smelling.
Sewage smell in the bathroom or shower
This is the most common case. If the bathroom smells like sewage, check these points in order:
- The shower drain: it is the trap that dries out first and where most hair and soap build up.
- The bottle trap: in many homes the bathroom drains join in a floor-level bottle trap; if it is dirty or dry, the smell comes out at several points at once.
- The base of the toilet: if the seal between the toilet and the drain is not watertight, the smell comes out at floor level next to the bowl.
- A drain that is not used: the bidet or a second washbasin can lose the water in their trap.
If it still smells after checking them, the source is further along the network.
What you can do yourself to remove the smell
- Refill the traps: run the taps of washbasins, showers and floor drains that are not used regularly.
- Clean the trap: take it apart (with a bucket underneath) and remove the built-up grease and residue.
- Clean the grate and plug of showers and washbasins, where hair and soap accumulate.
- Pour hot water down the drain to flush away recent grease.
- Use bicarbonate of soda and vinegar as a gentle maintenance clean, instead of corrosive products.
Avoid mixing chemicals and do not overuse bleach or harsh drain cleaners: they damage pipes and, if you have a septic tank, affect how it works. You will find more tips in how to clean drain pipes.
When to call a professional
- The smell comes back even after cleaning traps and drains.
- It smells in several parts of the house at once.
- Water drains slowly or you hear gurgling.
- There is damp near the pipes.
- You have a septic tank that has not been emptied for a long time.
In those cases, a domestic pipe inspection with a camera shows whether there is a blockage, a break or roots, and pressure cleaning removes the grease, sludge and sediment that cause the smell.
Frequently asked questions about bad smells from pipes
Why does the drain smell if it is not blocked?
Most often because the trap has dried out and lets sewer gases through, or because grease and residue stuck in the trap or on the pipe walls are decomposing.
Why do the pipes smell in a house that has been closed up?
Because the water in the traps evaporates over time. Without that water seal, sewer gases come up through the drains. Running the taps for a few seconds is enough to refill them.
Does bleach get rid of the bad smell from pipes?
It can mask it for a while, but it does not remove the built-up grease that causes it. In homes with a septic tank, harsh products also harm the bacteria that make it work.
When is a break causing the smell?
When the smell does not go away after cleaning traps and drains, appears in areas with no sanitary ware or comes with damp. A camera inspection can confirm it.
Can a full septic tank make the pipes smell?
Yes. If the tank is saturated, gases and wastewater flow back towards the house and the smell appears in several drains at once.
Why does the bathroom smell like sewage?
Usually because the shower drain, the bottle trap or a little-used drain has dried out, because dirt has built up in them or because the seal at the base of the toilet is not watertight. If the smell persists, the network needs to be checked.
If the smell comes back, the problem is further in
When cleaning the trap is not enough, the source is usually in the network: a partial blockage, a break, roots or a saturated septic tank.
At Limpiezas Domingo e Hijos we have been working on drainage networks for more than 15 years in the Marina Alta and La Safor, from Benidorm to Gandía. We inspect your pipes with a camera, locate the cause of the smell and remove it with pressure cleaning, unblocking or repair. You will find all the details on our unblocking and pipe cleaning service page.
Call us on 672 450 224 or 966 447 070, or request a quote.