Step 6: Refrigerant System Analysis and Leak Detection

Goal: Diagnose refrigerant system performance and detect leaks using visual inspection and basic diagnostic techniques

1. Perform visual inspection for refrigerant leaks:

   • Look for oil stains around line connections, service valves, and fittings
   • Check for ice formation on refrigerant lines (indicates possible leak or restriction)
   • Listen for hissing sounds that could indicate active refrigerant leaks
   • Expected result: Any visible signs of refrigerant leaks identified and documented

2. Check refrigerant line temperatures:

   • Feel the suction line (larger, insulated line) - should be cool/cold when system runs
   • Feel the liquid line (smaller line) - should be warm when system runs
   • Compare temperatures between both lines to assess system performance
   • Expected result: Temperature differences indicate proper refrigerant circulation

3. Inspect evaporator coil for ice formation:

   • Access the evaporator coil in the indoor unit (may require removing access panel)
   • Look for ice buildup on coil fins or refrigerant lines
   • Check for dirt accumulation that could restrict airflow and cause freezing
   • Expected result: Evaporator coil condition assessed for ice formation or blockages

4. Test cooling performance with thermometer:

   • Use a digital thermometer to measure supply air temperature at vents
   • Measure return air temperature at return grille
   • Calculate temperature split (return temp minus supply temp) - should be 15-20°F
   • Expected result: Temperature measurements indicate proper cooling performance

5. Check for proper refrigerant line insulation:

   • Inspect insulation on suction line for tears, gaps, or missing sections
   • Look for condensation on uninsulated portions (indicates insulation problems)
   • Check that liquid line is properly insulated where required
   • Expected result: All refrigerant lines properly insulated to prevent energy loss

6. Document system performance indicators:

   • Record system runtime and cycling patterns during operation
   • Note any short cycling or continuous operation issues
   • Document cooling capacity compared to outdoor temperature conditions
   • Expected result: Complete performance assessment documented for professional evaluation

If ice forms on evaporator coil: Check for dirty air filter or low refrigerant levels
If temperature split is less than 15°F: Indicates possible low refrigerant or airflow problems
If oil stains found: Contact EPA certified technician for leak repair and refrigerant service

You'll know you're done when: Refrigerant system performance is fully assessed and any issues are identified

• Visual inspection completed for refrigerant leak signs
• Line temperatures checked and compared
• Evaporator coil inspected for ice or dirt
• Cooling performance measured with temperature split calculation
• System performance documented for professional evaluation if needed

Ready for next step? You've assessed the refrigerant system and can now check the drainage system for proper condensate removal.