What does Zanotti error code HP mean?

Error code HP on Zanotti equipment indicates high pressure fault — check condenser and refrigerant charge. Refer to the Zanotti service manual for specific diagnostic steps and safety precautions before troubleshooting.

How do I reset a Zanotti unit after a fault?

To reset a Zanotti unit, first resolve the root cause of the alarm. Then power cycle the unit or press the reset button on the controller. For Zanotti systems with digital controllers, navigate to the fault log and clear active alarms. Never reset without investigating the cause.

Where can I find Zanotti service manuals and documentation?

Official Zanotti service manuals are available through authorised distributors and the Zanotti technical support portal. AskWhiz provides instant AI-powered access to Zanotti troubleshooting information via WhatsApp — no manual hunting required.

Which controller is fitted to my Zanotti monoblock or split unit?

Zanotti does not manufacture its own electronic controllers — monoblocks (MGM, MAS, MZ series) and split systems ship with third-party controllers, most commonly Carel (ir33 / EasyCold / SmartCella), Dixell (XR / XW series), or Eliwell (IDPlus / EWCM series). The controller varies by product line and production year. Open the electrical compartment, photograph the controller faceplate, and match the model to the OEM manual — the alarm dictionary belongs to the controller, not to Zanotti itself. AskWhiz can identify the controller from a photo and pull the matching code table.

What does HP mean on a Zanotti monoblock cold-room unit?

HP is a high-pressure switch trip on the condensing side. The mechanical HP cutout opens when discharge pressure exceeds the safety setting (typically 27–30 bar on R404A / R452A units), the controller logs the alarm, and the compressor latches off. On Zanotti MGM and MAS monoblocks, the most common causes are a fouled condenser coil, a failed condenser fan, refrigerant overcharge, or a high ambient temperature with poor airflow at the condenser side. Clean the condenser, verify fan operation, gauge the system, and reset the HP switch (some models latch mechanically) before the controller will allow restart.

What does LP mean on a Zanotti unit?

LP is a low-pressure trip — suction pressure dropped below the controller's cutout setting. On Zanotti BlockSystem-style monoblocks (MGM, MAS, MZ) and split systems, the most common causes are refrigerant undercharge or a leak, a closed thermostatic expansion valve (TXV), a frosted-over evaporator from a defrost-control fault, or a clogged liquid-line filter drier. Connect refrigerant gauges to confirm the alarm is real, leak-test the system if charge is low, inspect the evaporator for ice build-up, and check the TXV opening before recharging.

What does E1 or E2 mean on a Zanotti controller?

E1 and E2 on Zanotti equipment are NTC probe faults inherited from the underlying Carel, Eliwell, or Dixell controller. E1 typically flags the cabinet / room probe (Pb1 or S1) open-circuit, short-circuit, or out of range; E2 flags the defrost / evaporator probe (Pb2 or S2) with the same fault modes. With the controller powered off, disconnect the suspect probe and measure NTC resistance against the manufacturer's R-vs-T table — a 10 kΩ NTC reads about 32 kΩ at 0 °C and 10 kΩ at 25 °C. Replace the probe if it reads open, shorted, or far off the curve.

What does HI or LO mean on a Zanotti display?

HI and LO are temperature alarms that compare cabinet probe Pb1 against the configured high-temperature alarm threshold (HI) and low-temperature threshold (LO). They are usually auto-reset alarms that clear once temperature returns within the alarm differential. Common HI causes on Zanotti cold rooms are a dirty condenser, failed condenser fan, door left open, evaporator iced over, or a wrong setpoint; LO usually means the setpoint is too low for the application or the defrost is misconfigured. Confirm the alarm is real with an independent thermometer before assuming a controller fault.

How do I troubleshoot a Zanotti DFZ transport refrigeration unit?

Zanotti DFZ transport refrigeration units (truck and van bodies, cold-chain delivery) use dedicated transport controllers with their own alarm dictionary covering compressor, condenser fan, evaporator fan, vehicle-battery, and defrost faults. Common DFZ alarms cover low-battery / vehicle-engine-off conditions, high discharge pressure on hot ambient days, and evaporator-fan failures that prevent box pull-down. Always check the vehicle electrical supply (alternator output, battery isolator, fuse panel) before suspecting the refrigeration unit — transport units are extremely sensitive to undervoltage. The DFZ service manual lists the full code table; AskWhiz can pull the relevant section from a photo of the controller.

When should I call a Zanotti-authorised technician versus DIY?

DIY tasks: condenser cleaning, door-seal replacement, defrost-time-clock parameter adjustments, probe replacement, and clearing auto-reset HI / LO alarms after fixing the obvious cause. Call an authorised refrigeration technician for sealed-system work (refrigerant recovery requires EPA Section 608 in the US or F-Gas certification in the EU), compressor replacement, EEV or TXV replacement, and any HP latched fault that recurs after a single root-cause repair — a repeating HP usually means a deeper sealed-system problem that wrecks the compressor if left running. Zanotti's warranty terms also require authorised intervention to remain valid during the warranty period.

Quick Answer

Zanotti (Italian, part of Daikin Applied) builds monoblock cold-room units (MGM / MAS / MZ), split refrigeration systems, and DFZ transport refrigeration units. The displayed code depends on the controller fitted — typically Carel, Dixell, or Eliwell. Common codes: HP / LP pressure trips, SC / E1 / E2 probe faults, HI / LO temperature alarms, and DFZ-specific transport alarms.

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By Nichita Herput

Co-founder & CEO · Reviewed May 2026

What error codes does Zanotti display?

High-pressure switch trip — fouled condenser, failed fan, or refrigerant overcharge; clean condenser, verify fan, gauge the system before reset

Low-pressure trip — refrigerant undercharge, leak, closed TXV, or iced-over evaporator; gauge before adding charge

Sensor / probe fault — check temperature probe wiring and NTC resistance against the controller R-vs-T table

Cabinet / room probe (Pb1) NTC fault — measure resistance against the controller R-vs-T table and replace probe if out of range

Defrost / evaporator probe (Pb2) NTC fault — same diagnostic procedure as E1 on the evaporator-side sensor

High-temperature alarm — cabinet probe above alarm threshold; check door seals, defrost completion, condenser cleanliness, and fan operation

Low-temperature alarm — cabinet probe below alarm threshold; verify setpoint, alarm differential, and probe location inside the cabinet

EEPROM memory error on Carel-equipped Zanotti units — parameters corrupted; power-cycle, re-enter parameters, and replace controller if alarm returns

High discharge / compressor-head temperature — check superheat at suction, condenser fouling, and discharge thermistor

DEF

Defrost fault on Zanotti monoblocks — defrost cycle failed to terminate or defrost probe out of range; check defrost heater, timer, and Pb2 evaporator probe

Common questions about Zanotti equipment

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