Error messages

Compac dispensers and systems display error codes to alert users or technicians when something isn’t working as expected. Each code points to a specific issue — such as configuration errors, excessive flow, reverse flow, or problems with key components like the processor or K-Factor board. These codes are designed to speed up troubleshooting by clearly identifying the fault and often suggesting the required action (e.g. reconfiguring a setting, checking for leaks, or pressing a reset switch). If an error code appears, refer to the error message list to understand the cause and how to fix it. Quick action helps ensure the equipment runs safely and efficiently.

Error Code	Likely Cause	Suggested Action
Er 3 / Err 3	1. Price is not set in the Dispenser 2. Pump number is not set in the Dispenser	1. If the dispenser is connected to a site Controller, the price on the dispenser should be set to 0.00 and the pricing should be sent from the Controller. If the dispenser is not connected to a site Controller, the price must be set on the dispenser. 2. Set the hose number in the dispenser.
Er 8 / Err 8	Excessive Reverse flow	Check that product is not flowing back into the tank once the delivery has finished. This can occur if the non-return valves on site are leaking.
Er 9 / Err 9	The Flow Meter is in an illegal error state	Re-power the Dispenser. Check Meter cable for loose wires or bad connections. Replace the Meter or the Encoder board on the Meter.
Err 91	Meter sequence error	If 3rd Party Meter, check the wiring.
Er 10 / Err 10	Memory error Configuration data lost or corrupted	Re-configure Dispenser. If problem persists, replace Memory / Processor Board.
Er 12 / Err 12	Display Error	Replace Display.
Err 13	Slave board has restarted	Power failure Hardware failure
Err 14	K Factor Board offline	Check the Bus connections and C5K Power Supply.
Err 15	K Factor board has restarted	Power failure Hardware failure
Err 16	K Factor board is not talking to the LCD Display	Check wiring Replace K Factor board or LCD Display
Err 31	Transaction has ended but fuel is still flowing	Solenoid leaking
Er 41 / Err 41	Pump not communicating with Controller	1. If only one pump on the site is not communicating with the Controller, then the fault is likely to be in the pump: a. Check the comms wire connections on the comms board b. Check the Diagnostic LEDs on the Comms board in the Dispenser to diagnose cause c. Check the configuration and setup in the Dispenser 2. If all pumps on site are not communicating: a. Check the comms wire connections on the comms board b. Check comms cables between the Dispenser and the Controller c. Check setup and operation of the Controller
Er 50	Meter not communicating with Dispenser electronics	Check Meter connections. Check Dispenser configuration. Ensure the Meter ID in configuration matches the Meter hardware.
Er 52	Meter error	If the problem persists after repowering the unit, replace the meter.
Er 53	Meter stopped vibrating	Repower the unit. This may appear during startup and is normal. If it persists, replace the meter.
Er 54	Temperature sensor failure	Repower the unit. Replace the meter if the error continues.
Er 55	Meter not ready	Wait for the meter to calibrate. If the issue continues, repower the unit.
Er 61	Meter was not able to zero	This may be due to a leak or crystal build-up in the meter. Check for leaks/crystallization. Purge the line. If unresolved, remove the meter and pour hot water to dissolve crystals. If still not resolved, replace the meter.
Er 62	Meter could not reset batch	Try restarting the meter. Replace the meter if the problem persists.
Er 71	V50 meter is set but variant not selected	Configure device to either AdBlue / DEF or LPG.
Abd	Display offline / Display Fault	Check all display connections and the slave board configuration. If necessary, check and replace the display.
CNG 157	Dispenser expected no flow	Potential Solenoid Valve leak. Repair or rekit solenoid.
CNG 158	Tank volume predictor uncertainty	Check for leaks in the dispenser’s hose or fittings.
CNG 159	Temperature Probe out of range	Re-calibrate Temperature Probe.
CNG 160	Pressure Probe alignment error	Re-calibrate Pressure Probes.
CNG 161	Temperature Compensation calculation is uncertain
CNG 162	Generic CNG error with a number of potential causes
CNG 164	Pressure Probe error	Check / replace / re-calibrate Pressure Probe.
CNG 200	Unauthorised flow	Gas is flowing without the Start switch having been pressed to start a fill.
HOLD	Two types of HOLD error: 1. “Soft” HOLD error that resets after the unit is re-powered 2. “Hard” HOLD error that does not reset after re-power May also show Error 14	Re-power the unit. If the HOLD error resets but persists, the SD card may be corrupt and need replacement. Refer to SD replacement procedure. If it does not reset, possible hardware fault in Power Supply PCB / Processor PCB / K-Factor PCB / other PCB or Bus cable.
Calib c	K-Factor data integrity failure, or processor board replaced	Break the K-Factor switch seal and momentarily press the switch.
Calib p	K-Factor board swapped/replaced	Break the K-Factor switch seal and momentarily press the switch.
Calib	Unit needs calibration due to hardware change	Check K-Factor, temperature, and density calibration.
Calib f	K-Factor is not set or is 00.0000	Calibrate the unit and set the K-Factor.
Air	1. Air in the system 2. Density out of range 3. Coil amplitude too low while meter is operating (displayed until next sale)	Ensure pump is running. Check tank and pipework for leaks. Purge system. Increase solenoid delay on K-Factor switch.
Orun	Overrun – flow above preset	Check solenoid is closing. Increase the preset cutoff.
5ump	Sump error – liquid detected in the sump	Empty the sump. Check the dispenser for leaks. Check for water etc getting into the sump.
Ga5	LPG – Returned meter density too low	Calibrate meter density using the K-Factor switch.
ABDL	Display LCD error	Problem with K-Factor board talking to LCD. Check cables, plugs, etc. If issue persists, replace K-Factor board and/or LCD Display.
Er FLO	Excess Flow	Maximum flow rate exceeded. Increase max flow rate setting or restrict flow.
Er pr5t	Preset below MMQ	Enter a preset above or equal to the MMQ.
ER DEN	Density or Temperature out of Range	Calibrate meter density using K-Factor switch. Calibrate meter temperature using K-Factor switch.