Start with the symptom you recognize.
Choose the repair desk that matches what you are seeing. Read the safety notes before opening a fitting, removing a trap, or working near electricity.
Symptoms
Humming or jammed disposal
Clogged or slow drain
Leak or burst pipe
Dripping shower or faucet
No water or low pressure
Stop and get help: active flooding, sewage, suspected gas, electrical risk, structural damage, or a repair you cannot safely isolate.