Danfoss E1

What does Danfoss E1 mean?

E1 is the Danfoss controller's internal-fault message, shown on EKC and EKE series controls such as the EKC 313 superheat controller. The controller has detected a problem with its own electronics or program rather than with an external sensor or input. All four front-panel LEDs flash to indicate a regulation error, and the alarm relay is activated according to the configured priority.

Symptoms

• Display shows the message E1 when the top button is pressed.
• All four front-panel light-emitting diodes flash together.
• Alarm relay is activated at the factory priority of 1 (high priority).
• Refrigeration regulation is interrupted or unreliable.

Common causes

• Internal controller hardware fault.
• Corrupted or interrupted controller program.
• Power-supply disturbance affecting the controller electronics.
• Controller has reached the end of its service life.

Diagnostic steps

1. 01

   Acknowledge the alarm

   Briefly press the uppermost button to upload the error code to the display and cancel the active alarm so you can read the controller's current state.

2. 02

   Power-cycle the controller

   Switch the supply voltage off, wait, then restore power. A clean restart can clear a transient internal fault caused by a power disturbance.

3. 03

   Check the supply voltage

   Verify the 24 V AC supply is stable and within tolerance, as an unstable supply can trip the internal fault detection.

4. 04

   Replace the controller if E1 persists

   If the fault returns after a restart it indicates a hardware fault inside the controller; fit a replacement of the same type and software version.

When to call a professional

E1 points to a fault inside the controller itself, not a field-repairable sensor or wiring problem. If a power-cycle does not clear it, a refrigeration technician should confirm the supply voltage, transfer the configuration, and replace the controller. The work involves mains-adjacent low-voltage wiring and correct re-commissioning of the superheat or temperature regulation, which should be carried out by trained staff.