J & E Hall – JCC Series Cellar Coolers

Cellar too warm; Compressor not running (No cooling at all, fans might be running)

– Verify power supply and that the unit is switched on (check mains and fuses). – Check if the digital controller is calling for cooling (cooling LED on). Ensure the setpoint is below current cellar temp. – Listen/observe if the compressor contactor is energizing. If the contactor coil isn’t pulling in, the control circuit could be open – check any safety cut-outs. – Examine safety switches: is the High-Pressure (HP) switch tripped? (Some units have a manual reset button on the outdoor unit.) Is the Low-Pressure (LP) switch open? Each will prevent compressor start.

– Restore power or correct supply issues (blown fuse, etc.). – If control issue: repair/replace faulty thermostat or controller not sending a cooling signal. – If HP trip: check condenser for blocked coil or fan failure causing high pressure. After allowing pressure to equalize, reset the HP switch (on qualified technician’s advice) and clean/repair the condenser (e.g. remove debris, replace faulty fan). – If LP trip: likely low refrigerant or airflow issue. Inspect evaporator coil for ice (a sign of low pressure) and fan operation. Thaw any ice and fix cause: e.g. replace evaporator fan motor if not running, or find & repair refrigerant leak and recharge system. – If contactor faulty or coil burned out, replace the contactor or coil.

Compressor runs but cellar still warm (poor cooling) (Evaporator fans running, compressor on, but cellar temperature stays high)

– Check if the evaporator coil is frosted over (visible ice) – this indicates poor heat transfer (often due to low refrigerant or very low airflow). – Feel the airflow: Is the evaporator fan blowing strongly? If weak or not at all, the coil may ice up. – Observe system pressures (technician use gauges): low suction pressure can mean undercharge or expansion valve blockage; high discharge pressure can mean an overcharge or condenser problem. – Ensure doors to the cellar aren’t open excessively (warm air ingress can overwhelm the unit). Also verify the fan speed controller (if fitted on condenser) is not set too low causing high head pressure in hot weather.

– Defrost the evaporator if iced: shut off the compressor or entire unit to let ice melt (do not chip at it). Find cause: if an evaporator fan motor is bad, replace the fan motor so the coil won’t freeze. – If refrigerant leak suspected (oily residue on joints, low pressures), a certified technician should leak-test, repair, and recharge the system. After recharge, ensure sight glass shows few bubbles and proper subcool/superheat. – If expansion valve or filter drier is clogged (indicated by low suction and maybe frost at valve), the tech should clean or replace the TXV/drier and pull a vacuum/recharge. – For high head pressure: clean the condenser coil, make sure its fan runs at full speed in high ambient (most JCC units have a head pressure controller that may need adjustment). – Reduce thermal load: keep cellar door closed; avoid heat sources in cellar (like big appliances near the evaporator).

Unit short-cycles (frequent stop-start) (Compressor turns on and off every minute or two; temperature swings)

– Check if it’s cutting out on a safety switch: e.g. LP switch might stop the compressor shortly after start if refrigerant is low (listen for compressor then a click off). Low refrigerant can cause rapid cycling on LP. – Ensure the anti-short-cycle timer in the controller is set (most have a 3-5 minute delay by default to prevent rapid cycling). If someone set it too low or bypassed it, that could cause frequent restarting. – Verify the thermostat differential isn’t too tight. J&E Hall recommends at least a 2°C differential to avoid short-cycling. – See if room load changes are causing quick cycling – e.g. very low load at night coupled with an overpowered unit can lead to brief runs; in such cases, adding a heater load or wider differential helps.

– If low refrigerant is confirmed (bubbling sight glass, LP trips), perform refrigerant leak repair and recharge as above. This will stabilize pressures and stop LP cut-out cycling. – Adjust the controller settings: program a minimum 3-minute compressor off-cycle delay (most digital controllers like Dixell or LAE have this setting). Set an appropriate temperature differential (e.g. on at 12°C, off at 11°C) so the compressor doesn’t rapid-fire. – If short-cycling occurs only in cooler weather, consider installing a crankcase heater and ensure head pressure controls maintain adequate condensing pressure – this prevents refrigerant migration and hunting. – Replace a faulty thermostat or sensor if it’s erratically reading temperature and causing on/off toggling. A sensor reading error may not throw a code but can mislead the controller. Double-check calibration or swap the probe if needed.

Controller displays error code (E.g. “P1”, “P2”, “HA”, or similar on display)

– Refer to the JCC manual’s alarm codes: P1 or PFo indicates the room (air) probe is faulty or disconnected, and P2 or PFc indicates the evaporator coil probe is faulty. HA means the room got too warm (High temp Alarm), LA means too cold (Low temp Alarm). – Check the physical connection of the sensor corresponding to the code. For P1/P2, the probe might be loose or broken. Test the probe resistance if possible to confirm failure. – If “HA” alarm (high temp) and the unit is running, it suggests the cellar temp stayed >2°C above setpoint for 30+ minutes. That could result from a propped-open door, an under-capacity unit, or another fault preventing cooling. Investigate other issues (like those above: condenser, fans, refrigerant). – If “LA” alarm (low temp), the cellar went too cold – possible causes: controller setpoint error, probe misreading (or located in a cold spot), or a contactor stuck on.

– Probe faults (P1/P2): Replace the faulty temperature sensor probe with an equivalent part. After replacement, reset the power to clear the latched error. Make sure the new probe is properly placed (air sensor in return airflow, coil sensor on evaporator exit) and securely connected. – Temperature alarms (HA/LA): Once the underlying issue is fixed (closed door, repaired cooling fault), the alarm will reset automatically when temperature returns to range. You can acknowledge the alarm if your controller has that feature or simply monitor until it clears. – If nuisance high-temp alarms occur, consider an auxiliary cellar fan or alarm delay. J&E Hall units allow a 30-minute delay by default – ensure it’s set appropriately. Persistent HA alarms mean the unit struggles; have a technician verify capacity vs. load (maybe your stock or heat load has increased beyond the unit’s rating). – After any probe replacement or alarm, verify the setpoint and settings haven’t reset. Reconfigure the controller as needed per the manual (some JCC controllers revert to defaults if powered off with probe errors).