Compare fixtures
Say whether a basin or toilet using the same unit still clears normally. Include whether the pump starts while shower water collects.
Keep model identity
Not every wastewater pump is a toilet macerator. Give the actual model and connected fixtures so the enquiry is screened correctly. Do not add chemicals to force drainage through an uncertain restriction.
A useful distinction
A shower can drain slowly before enough water reaches the pump to start it. Describe the pump response and water level separately so a shower-trap enquiry is not automatically treated as a failed wastewater unit.