Air conditioner not cooling: narrowing down the problem
A room failing to reach its set temperature does not prove that refrigerant is low. Separate weak airflow, warm supply air and a room gaining more heat than the system can remove.
Three different symptoms
If very little air comes out, inspect user-accessible filters and check that furniture is not blocking the inlet or outlet. If airflow is strong but warm, confirm cooling mode and the set temperature. If the area near the unit cools but other rooms do not, describe the layout: one indoor unit does not guarantee cooling across separate rooms.
A useful check without dismantling
Record the mode, set temperature, open rooms and approximate running time. Note whether the problem appeared suddenly or developed over weeks. Do not keep lowering the setting to compensate. Stop the check and request assistance if you see ice, water on electrical connections or an unusual smell.
What a diagnosis should establish
Tell the technician whether heating also fails and whether other units on the system work normally. This helps separate controls, airflow and component faults. Ask for the cause and proposed scope before agreeing to a recharge or replacement; a temporary improvement does not establish that the underlying issue has been resolved.
Choose the next step
Use the symptom page to understand the likely causes. If the cause is still unclear, book a diagnosis before approving a repair.