Lennox EL296UHV Error Code E 116: High 24V Power

What Does Code E 116 Mean?

Error code E116 on the Lennox EL296UHV indicates that the 24-volt control circuit voltage has exceeded the acceptable range (18 to 30 volts). The 24-volt supply is generated by a transformer that steps down the main line voltage, so high 24V output usually means the input voltage to the transformer is too high.

The most common cause is incorrect line voltage being supplied to the furnace. If the furnace is connected to a 240-volt circuit when it requires 120 volts, the transformer will produce an excessively high secondary voltage. This can also occur if the utility voltage is running high, though the E113 code would typically appear first in that case.

The alarm clears automatically when the control board senses proper voltage. An electrician should verify the supply voltage at the furnace disconnect and confirm it matches the nameplate rating. If the line voltage is correct but the 24V is still high, the transformer itself may be faulty and producing excessive output.

Common Causes

When to Call a Professional

Contact a licensed HVAC technician if:

• The furnace displays E116 indicating high 24V power
• You suspect the furnace may be connected to the wrong voltage circuit
• The issue appeared after electrical work on the home

✓ Verified against manufacturer service manual — March 2026