FAQs | SEWER SMELLS AND DRAINAGE NOISES
Why Does My Bathroom Smell Like Sewage?
What might you be experiencing?
You may notice a persistent sewage or rotten-egg smell coming from the shower, basin, bath, toilet or floor waste. The odour may become stronger after using plumbing fixtures, during windy weather, when an exhaust fan is running, or after a bathroom drain has not been used for some time. You might also notice gurgling drains or slow water flow.
What’s likely causing the problem?
Sewer smells commonly occur when a water seal inside a trap has dried out, allowing gases to enter through an unused floor waste, shower or basin drain. Other possible causes include a blocked drain, damaged or poorly sealed toilet connection, leaking waste pipe, faulty air-admittance valve or inadequate drainage ventilation. A build-up of hair, soap residue and bacteria inside a drain can also create an unpleasant smell that resembles sewage.
What can you do to fix it?
Run water into every bathroom fixture and floor waste to refill the traps, then clean accessible drain grates and remove any built-up debris. Check around the toilet for movement, moisture or damaged seals, but avoid using chemical drain cleaners because they may damage pipework and create safety risks. If the smell persists, the drains gurgle or wastewater backs up, contact a licensed plumber to inspect the traps, toilet connections, ventilation and drainage system.
Why Does My Laundry Floor Waste Smell?
What might you be experiencing?
You may notice a sewage-like, musty or stagnant-water smell coming from the laundry floor waste. The odour may be stronger after the floor waste has not received water for some time, when the washing machine drains, during windy weather or while an exhaust fan is operating. You might also hear gurgling or notice slow drainage.
What’s likely causing the problem?
The floor waste’s water seal may have dried out, allowing sewer gases to enter the laundry. Other possible causes include a build-up of lint, detergent residue and bacteria, a partial drain blockage, incorrect waste connections or inadequate drainage ventilation. A damaged trap, leaking pipe or pressure changes within the drainage system can also disturb or remove the protective water seal.
What can you do to fix it?
Pour clean water into the floor waste to restore its water seal, then remove and clean the grate and any accessible debris. Regularly adding water can help if the drain is rarely used. Avoid pouring chemical drain cleaners into the waste, as they may damage pipework and create safety hazards. If the smell quickly returns or you notice gurgling, slow drainage or wastewater backing up, contact a licensed plumber to inspect and clear the drainage system.
Why Does the Sewer Smell Come and Go?
What might you be experiencing?
You may notice a sewage or rotten-egg smell that appears only at certain times, such as after using a shower, toilet or washing machine, during windy weather, following heavy rain, or when an exhaust fan is running. The odour may come from a floor waste, basin, shower, toilet or another part of the property before disappearing again.
What’s likely causing the problem?
An intermittent sewer smell can occur when a drain trap dries out or loses part of its water seal, temporarily allowing sewer gases into the property. Pressure changes caused by poor drainage ventilation, partial blockages or other fixtures discharging can also disturb the trap seals. Other possible causes include a loose toilet connection, faulty air-admittance valve, cracked waste pipe, blocked vent or debris and bacteria accumulating inside a drain.
What can you do to fix it?
Run water through every fixture and pour clean water into rarely used floor wastes to refill their traps. Clean accessible drain grates and note when and where the smell occurs, as this can help identify the cause. If the smell continues, avoid trying to mask it with chemicals. Contact a licensed plumber to inspect the trap seals, toilet connections, drainage ventilation and pipework, and carry out a CCTV drain Tape inspection if a blockage or damaged pipe is suspected.
Why Do Drains Smell After Being Unused?
What might you be experiencing?
You may notice a sewage-like, musty or stale smell coming from a shower, basin, bath, laundry tub or floor waste that has not been used for some time. The odour may be strongest when you first enter the room, run an exhaust fan or begin using the fixture again.
What’s likely causing the problem?
Most plumbing fixtures contain a trap that holds water and prevents sewer gases from entering the property. When a drain remains unused, this water can gradually evaporate and break the protective seal. Unpleasant smells may also come from bacteria, soap residue, hair or other debris accumulating inside the drain. Less commonly, the cause may be a leaking trap, poor drainage ventilation or damaged pipework.
What can you do to fix it?
Run water into the affected fixture for approximately 30 seconds and pour clean water into any unused floor wastes to restore their water seals. Remove and clean accessible grates, strainers and debris. Regularly running water through rarely used drains can prevent the traps from drying out. If the smell returns quickly or is accompanied by gurgling, slow drainage or wastewater backing up, arrange an inspection with MAS Plumbing Solutions
Why Does Flushing the Toilet Make the Shower Drain Gurgle?
What might you be experiencing?
When you flush the toilet, you may hear bubbling or gurgling sounds coming from the shower drain, bath, basin or floor waste. The shower may also drain slowly, release unpleasant sewer odours or experience water rising through the drain. In more serious cases, wastewater may begin backing up into the lowest bathroom fixture.
What’s likely causing the problem?
Gurgling usually indicates that air cannot move freely through the drainage system. A partial blockage in the shared sewer line may force displaced air back through the shower trap when the toilet is flushed. Other possible causes include a blocked or incorrectly installed drainage vent, damaged pipework, tree-root intrusion or an incorrectly graded drain. The shower often shows symptoms first because it is one of the lowest fixtures.
What can you do to fix it?
Avoid repeatedly flushing the toilet or using nearby fixtures if water is rising through the shower drain, as this could cause a sewage overflow. Do not use chemical drain cleaners, because they may damage pipework and create hazards for anyone working on the drain. Arrange an inspection with MAS Plumbing Solutions to locate the cause using appropriate testing and CCTV drain-camera equipment. The blockage can then be cleared and any damaged pipework or ventilation faults repaired.
How Do I Know if My Sewer Vent Is Blocked?
What might you be experiencing?
You may notice drains gurgling when a toilet is flushed, fixtures draining slowly, fluctuating water levels in toilet bowls or recurring sewer smells inside the property. Bubbles may also appear in the toilet when nearby sinks, showers or washing machines discharge.
What’s likely causing the problem?
A sewer vent allows air to enter and escape from the drainage system so wastewater can flow without disturbing fixture trap seals. Leaves, debris, bird nests or other obstructions can restrict an external vent opening. Similar symptoms may also be caused by a partial sewer blockage, damaged pipework, inadequate ventilation or an incorrectly installed drainage system.
What can you do to fix it?
Check for obvious debris around any safely accessible vent opening from ground level, but do not climb onto the roof or insert tools into the pipe. Avoid using chemical drain cleaners, as they will not clear a ventilation fault and may create additional hazards. Arrange an inspection with MAS Plumbing Solutions to determine whether the issue is a blocked vent, restricted sewer line or another drainage fault and complete the necessary repairs.
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