Refrigeration troubleshooting centre
Search the 130 technical guides: describe what happens, which component is involved and when it occurs. Find the initial checks and open the most relevant pathway.
The guidance provides initial checks and does not replace the manufacturer’s instructions, a risk assessment or the competence required to work with electricity, pressure systems and refrigerants.
Choose a topic
No results found. Try a shorter symptom, such as ‘pressure’, ‘frost’, ‘sensor’ or ‘compressor’.
Field troubleshooting
The search engine directs the checks; it does not confirm a cause. Identify the refrigerant, allow the system to stabilise and compare every reading with the manual and design conditions.
Use combinations of symptoms and SH/SC trends as guidance. For zeotropic refrigerants, use the correct dew and bubble points; for CO₂ and R290, follow the applicable procedure and use suitable instruments.
The four combinations indicate a direction for further checks, not a confirmed diagnosis. Load conditions, electronic control, system type and measurement point can alter the interpretation.
Observed pattern: starved evaporator, suction pressure tending to be low and potentially reduced capacity.
First action: check for leaks, verify the documented charge, confirm actual subcooling and investigate a possible restriction.
Observed pattern: localised temperature drop, starved evaporator and liquid available upstream.
First action: compare temperatures upstream and downstream of the filter, valve and solenoid; do not adjust the TXV without supporting measurements.
Observed pattern: cold suction return, risk of liquid reaching the compressor or elevated condensing pressure.
First action: check the bulb or sensor, valve control, charge and condensing conditions; protect the compressor.
Observed pattern: possible liquid return, no airflow or a heavily frosted coil.
First action: reduce the risk to the compressor; check airflow, fans, defrost and expansion control.
Priority procedures
The guides put the initial checks in order. Stop and refer to the specific manual before working on electrical systems, pressure systems, flammable refrigerants or transcritical CO₂.
Air or other non-condensable gases take up space in the condenser and can raise condensing pressure above that expected for the operating conditions.
Allow the system to stabilise; first rule out inadequate heat transfer and overcharge. Then compare the readings with the P/T chart for the correct refrigerant and the manufacturer’s manual.
OPEN REF TOOLS ↗High SH and low SC are a possible trend, not confirmation. Isolate, test and repair in accordance with the procedure; avoid repeated topping up without locating the cause.
CHOOSE A LEAK-DETECTION METHOD →A restriction can retain liquid upstream and starve the evaporator. Follow the measurement sequence and the manual; do not compensate by adjusting the expansion valve.
VIEW LINE COMPONENTS →An air-side or water-side fault can resemble a refrigerant charge problem. Restore correct heat transfer and reassess the readings only after the system has stabilised.
HEAT-TRANSFER GUIDE →Possible liquid slugging, oil foaming or an abnormally cold suction line require caution: do not pursue display-case performance at the expense of the compressor.
The cause may be control, frost, the bulb or sensor, or a transient condition. Assess behaviour over a complete cycle and refer to the compressor manual.
OPEN GUIDED PATHWAY →Do not bypass the device or raise its settings to keep the system running. Identify the primary cause: heat transfer, load, voltage, current or actual pressure.
OPEN PRESSURE-SWITCH TROUBLESHOOTING →If the answer is not enough
Checks on electrical parts, pressurised systems and refrigerants must be carried out by trained and authorised personnel using suitable instruments, personal protective equipment, current manuals and applicable procedures.
