Thermostat displays E11 and indicates high internal temperature or shuts down display

Safety first: Turn off power to the HVAC system if you will be relocating or rewiring the thermostat.

Steps to troubleshoot:

• 1. Check installation location: Ensure the Emerson thermostat is not in direct sun, near ovens, or above electronics that emit heat. It should be on an interior wall away from drafts and heat sources.
• 2. Inspect wall opening: Remove the thermostat and check if hot air from wall cavities or duct chases is leaking through the wiring hole. Seal large openings with non-flammable insulation or foam.
• 3. Clear vents: Make sure the thermostat’s side and bottom vents are not blocked by paint, dirt, or decorative covers.
• 4. Allow cool-down: Turn off the HVAC system and let the thermostat cool for 30 minutes. Restore power and see if E11 clears.
• 5. Relocate if necessary: If the location is inherently hot, have the thermostat moved to a more suitable interior wall.

When to call a professional: If E11 occurs even in a cool, shaded location, the internal temperature sensing or power circuitry may be failing; contact an HVAC technician or Emerson support for replacement.