Honeywell Error Code E351: Equipment Fault

How to Fix Honeywell Code E351

1. Step 1: Check the air filter. A dirty filter restricts airflow and can cause various issues. Replace it if it's dirty.
2. Step 2: Reset the system. Turn off the power to the unit at the breaker for 60 seconds, then turn it back on. This might clear a temporary fault.
3. Step 3: If the error persists after these steps, contact a qualified HVAC technician for diagnosis and repair.

How to Reset Honeywell Code E351

1. Remove the thermostat from its wall plate.
2. Remove the batteries and wait 30 seconds.
3. Reinsert the batteries and snap the thermostat back onto the wall plate.
4. If the error persists, perform a factory reset through the menu: Menu > Preferences > Restore Factory Defaults.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Honeywell Error Code E351 Mean?

The Honeywell E351 error code indicates a general equipment fault within your HVAC system. This is a broad error, meaning the control board has detected an issue but needs more information to pinpoint the exact problem. It's like a 'check engine' light in your car – it tells you something's wrong, but not specifically what. This error can affect various components, from the blower motor to the ignition system (if it's a furnace) or the compressor (if it's an AC or heat pump). Because the system has locked out, you won't have heating or cooling until the fault is resolved. Ignoring this could lead to further damage or discomfort.

Common Causes

• Flame sensor failure or contamination (furnaces)
• Blower motor failure or obstruction
• Ignition failure (furnaces)
• Failed or shorted wiring harness
• Faulty control board

Diagnostic Steps

Replacement Parts

Related Codes on Same Models

Other codes that affect the same Honeywell model families as E351.