In what situation is it recommended to perform a leak check on a refrigerant system?

Performing a leak check on a refrigerant system when the system is not cooling properly is a recommended practice because a drop in cooling efficiency can be a strong indication of a refrigerant leak. Refrigerant is essential for the cooling cycle, and if there is insufficient refrigerant due to a leak, the system will struggle to absorb heat effectively, leading to poor performance. By conducting a leak check in this scenario, technicians can identify and address any leaks, ensuring that the system operates efficiently and effectively, restoring its cooling capabilities.

The other situations also represent valid times to check for leaks; for example, the manufacturer's recommendations, post-installation checks, and during seasonal maintenance are all critical periods where a leak check can be beneficial. However, focusing on the immediate operational issue—poor cooling performance—makes it urgent and essential to check for leaks in that context.