Display shows E015; unit may not respond to user inputs or may freeze on one screen.

Safety: Turn off power before removing the control board cover. Static discharge can damage electronics; ground yourself before handling boards.

Steps:

• 1. Power cycle: Turn off power at the breaker for at least 60 seconds, then restore. Sometimes this clears transient control errors.
• 2. Inspect control compartment: Look for signs of water leaks, condensation, or insect infestation on or around the control board. Correct any moisture source.
• 3. Check connectors: Reseat all low-voltage and sensor connectors on the control board to ensure good contact.
• 4. Firmware update (if applicable): On some Lochinvar models, a technician can update firmware using a service tool. Contact an authorized service provider.
• 5. Replace control board: If E015 persists and wiring/sensors are verified good, replace the main control board with the correct Lochinvar part.