ER04

The error ER04 is the shutdown due to high water temperature. If the water temperature exceeds the value of parameter Th25, then the stove will go into ER04.

The possible causes are:

- Air in the system

Reset the safety thermostat and clear the error. Bleed the air from the system from one of the radiators.

- Circulator blocked

Reset the safety thermostat by clearing the error and check the proper functioning of the circulator via System Menu / Output Test.
Warning: after prolonged disuse of the boiler, deposits of
lime scale may form in the circulator. Replace the circulator in case of malfunction.

- Undersized system

Check if the heating system is undersized and therefore does not allow optimal heat dissipation. Perform tests by removing the automatic power and setting lower combustion powers.

- Faulty boiler probe 

Clear the error and restart the boiler. If the thermostat temperature is not accurate or if the error reoccurs immediately, it is likely that the boiler probe is faulty. Check the wiring.
Replace in case of malfunction.