Question 1

Chiller won't start, or starts then cuts out, in cold weather

Accepted Answer

Likely causes: Ambient temperature has dropped to around 5°C or below. The chiller runs a built-in cold-weather safety mode, briefly attempting to start before shutting down. This protects the compressor, pump and pipework from freezing and mechanical stress. It is not a fault. What to do: Don't repeatedly attempt to restart the chiller. Wait for ambient temperatures to rise, typically above 5–6°C. Normal operation resumes automatically. Keep the power on and water circulating: moving water is far less likely to freeze than standing water. If temperatures stay below zero and the chiller will not run, drain down instead — turn it off, drain the chiller and all external pipework, leave isolation valves open and disconnect hoses where possible. Never add antifreeze or additives; they damage internal components and void the warranty. Full guidance is on our Care & Maintenance page.

Question 2

P01: Water Flow Switch Failure

Accepted Answer

Likely causes: Insufficient water flow through the chiller. Air trapped in the circulating water pipe. Plunge water level too low. Circulating pump damaged or seized. What to do: Check the water level — make sure the plunge is filled to the recommended line. Clean the water filter and pre-filter (see Care & Maintenance). Bleed any trapped air from the system by briefly loosening the particle filter chamber until a small amount of water begins to escape. Once water appears, retighten the filter chamber securely. If the issue persists, the circulating pump or capacitor may need replacing — contact support.

Question 3

P25: Ambient Temperature Protection

Accepted Answer

Likely causes: The air temperature around the chiller is too high or too low for safe operation. Working temperature range: 1°C–45°C ambient. Chiller installed in a poorly ventilated space. What to do: Make sure there's at least 50cm clearance behind the chiller fan for airflow. If outdoors in hot weather (>40°C), shade the chiller or relocate to a cooler spot. If indoors, check the room isn't trapping heat — open ventilation or move the unit. In freezing conditions, either keep the chiller powered on (anti-freeze protection runs) or drain it fully — never leave water in a powered-off chiller in winter.

Question 4

E01: Exhaust Temperature Sensor Failure

Accepted Answer

Likely causes: Sensor probe detached or damaged. Loose connection between sensor and motherboard. Sensor wire disconnected or shorted. What to do: This usually needs a service visit — the exhaust temperature sensor needs reseating or replacing. Contact support with the error code and your order number.

Question 5

E05: Coil Temperature Sensor Failure

Accepted Answer

Likely causes: Coil temperature sensor probe detached or damaged. Loose interface between sensor and main board. What to do: Contact support — the coil sensor needs to be reseated or replaced by a technician.

Question 6

E09: Return Air Temperature Sensor Failure

Accepted Answer

Likely causes: Return air sensor probe loose or damaged. Sensor wire disconnected or shorted. What to do: Contact support — needs a technician to reattach or replace the return air sensor.

Question 7

E18: Outlet Water Temperature Sensor Failure

Accepted Answer

Likely causes: Outlet water sensor probe detached from its housing. Sensor wire damaged or shorted. What to do: Check the outlet water sensor probe is firmly seated in its sleeve on the water pipe. If reseating doesn't clear the code, contact support for sensor replacement.

Question 8

E19: Inlet Water Temperature Sensor Failure

Accepted Answer

Likely causes: Inlet water sensor probe detached or damaged. Loose connection at the motherboard. What to do: Check the inlet water sensor probe is firmly seated. If the error persists after reseating, contact support.

Question 9

E21: Communication Failure with Control Panel

Accepted Answer

Likely causes: Loose signal cable between the control panel and the chiller motherboard. Damaged signal line. What to do: Power off the chiller at the mains, wait 30 seconds, and power back on. If the error returns, the signal cable between the panel and motherboard needs reconnecting or replacing — contact support.

Question 10

E22: Ambient Temperature Sensor Failure

Accepted Answer

Likely causes: Ambient temperature sensor damaged or disconnected. What to do: Contact support — the ambient sensor needs replacing by a technician.

Question 11

P02: High-Voltage Protection

Accepted Answer

Likely causes: High-pressure switch damaged. Insufficient water flow (heating mode). Fan not rotating or blocked airflow (cooling mode). System clogged or inlet temperature probe loose. What to do: Check the chiller fan is spinning freely and the vents are clear of debris. Verify good water flow through the system (see P01 fixes). If the fan won't spin or the code persists after clearing obstructions, contact support — the high-pressure switch may need replacing.

Question 12

P06: Low Pressure / Refrigerant Protection

Accepted Answer

Likely causes: Low pressure switch damaged. Insufficient refrigerant in the system (likely a leak). Evaporator clogged or dirty fin surface. What to do: Inspect and clean the evaporator fins on the side/back of the chiller. If the code returns, this typically indicates a refrigerant leak and requires a service visit — contact support.

Question 13

P11: Exhaust Gas Temperature Overshoot

Accepted Answer

Likely causes: Insufficient refrigerant. Blocked or clogged refrigerant circuit. What to do: Contact support — this requires a system diagnostic and likely refrigerant top-up by a technician.

Question 14

P15: Excessive Inlet/Outlet Temperature Difference

Accepted Answer

Likely causes: Water flow through the chiller is too low. Air trapped in circulating pipes. Pump damaged or plunge water too low. What to do: Check the plunge water level is full. Clean the water filter and pre-filter. Bleed air from the circulating pipes. If the pump sounds weak or noisy, contact support.

Question 15

P16: Refrigeration Over-Cooling Protection

Accepted Answer

Likely causes: Set temperature too low combined with low water flow. Water filter blocked. What to do: Check your set temperature isn't unrealistically low (3°C+ is typical). Clean the water filter and pre-filter to restore proper flow. Check the water pump is running normally.

Question 16

P17: Standby Anti-Freeze Protection

Accepted Answer

Likely causes: Water and ambient temperatures are very low while the chiller is in standby. This is a protective feature — not necessarily a fault. What to do: Keep the chiller powered on through winter so the anti-freeze protection cycles automatically. Alternatively, drain the chiller and pipes completely if storing for winter.

Question 17

P23: Low Water Temperature Protection

Accepted Answer

Likely causes: Set temperature is too low. Water flow is insufficient. What to do: Raise the set temperature slightly (e.g. above 3°C). Clean the water filter to improve flow. Check the water pump operates normally.

Question 18

P26: Heating Water Temperature Overheat

Accepted Answer

Likely causes: Insufficient water flow in heating mode. Air in circulating pipes. Pump damaged or plunge water shortage. What to do: Check the plunge water level is full. Clean the water filter and pre-filter. Bleed air from the circulating pipes. If the pump is faulty, contact support.

Question 19

P27: Cooling Coil Over-Temperature Protection

Accepted Answer

Likely causes: Air temperature around the chiller is too high. Hot air being recirculated back into the chiller (short circuit of airflow). Obstructions blocking ventilation. What to do: Move the chiller out of direct sunlight or away from heat sources. Ensure at least 50cm clearance behind the fan and 100cm of free space around the unit. Make sure no walls or barriers cause hot exhaust to flow back into the intake.

Knowledge Base

Most common

All error codes

Something else?