A grease trap that still smells after cleaning needs investigation, not an automatic second pumping or a chemical treatment chosen at random.
How to approach the decision
Write down when the smell started, where it is strongest and whether it changes during washing, cooking or quiet periods. Give the contractor the previous service report and explain whether the problem existed before that visit.
Ask the service company to identify what was cleaned and what remains outside its scope. A plumber may need to investigate drainage, seals or ventilation rather than the pumping contractor repeating the same work. Do not open unfamiliar chambers or mix cleaning products to investigate the smell yourself.
Schedule inspection with access to the affected area and plan around food preparation and customers. Agree in advance how the contractor will contain disruption, document findings and explain any proposed additional work.
Frequently asked questions
Why does the grease trap still smell after it has been cleaned?
A persistent smell can require investigation of the installation or connected drainage. Ask for findings rather than assuming the cleaning failed.
Should grease trap cleaning take place while customers are still in the restaurant?
Plan the work around hygiene and operational controls. Discuss isolation and reopening arrangements with the contractor before scheduling.
Could a persistent sewage smell come from something other than the grease trap?
Yes. Describe the location and timing so the professional can assess the wider drainage system as appropriate.
What information should I send a contractor before booking an odour investigation?
Send the service date, trap details, photographs taken safely, where the smell occurs and any drainage symptoms.
Sources and context
Community discussions informed the questions addressed here; they are not technical or legal authority. The guidance above is general decision support, not a site-specific diagnosis or legal opinion.
- Grease trap got cleaned last week, still smells
- Advice desperately needed — sewage smell
- Cleaning the grease trap while still open