technical:air_conditioning_system:dash:chart

Diagnostic Chart for Air Conditioning System
Condition Low Side Pressure High Side Pressure Sight Glass Suction Line Receiver Dryer Liquid Line Discharge Line Discharge Air
Lack of Refrigerant Very low Very low Clear Slightly cool Slightly warm Slightly warm Slightly warm Warm
Lack of Refrigerant Low Low Bubbles Cool Warm to hot Warm Warm to hot Slightly cool
Compressor Failure High Low Clear Cool Warm Warm Warm Slightly cool
Condenser Malfunction High High Clear to occasional bubbles Slightly cool to warm Hot Hot Hot Warm
Expansion Valve Stuck Open High High to Normal Clear Cold - sweating or frosting heavily Warm Warm Hot Slightly cool
Expansion Valve Stuck Closed Low Low Clear Cold - sweating or frosting heavily at valve inlet Warm Warm Hot Slightly cool
Restriction between Condenser and Expansion Valve Low Low Clear Cool Cool or sweating or frosting Cool or sweating or frosting Hot to point of restriction Slightly cool
Restriction between Compressor and Condenser High High, normal or low Clear Slightly cool to warm Warm or hot Warm or hot Hot Warm
Normal Normal Normal Clear Cool Possible light sweat Warm Warm Hot Cool
Source: Dan, Brattain Int'l Salem, OR
08/12/12