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Error code reference

Lennox Furnace Error Code E 114

Line voltage frequency out-of-range (no 60 Hertz power).

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What the E 114 error code actually means

Your Lennox furnace detected that the electrical power coming into it is not running at the correct frequency it needs to operate safely. This is similar to the furnace receiving the wrong type of electricity, often caused by a power quality issue from your utility company or a generator supplying incorrect power. Once the electricity returns to normal, the furnace should restart on its own within a few seconds.

Diagnostic procedure

The full E 114 procedure

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1
First diagnostic step
Check voltage and line power frequency. Correct voltage and frequency problems. System resumes normal operation 5 seconds after fault recovered.
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Most common causes of E 114

Ranked by how often they cause this code
  1. 1Utility power quality issue
  2. 2Generator with incorrect output frequency
  3. 3Inverter or UPS supplying non-standard frequency
  4. 4Loose or corroded wiring at the electrical supply
  5. 5Faulty furnace control board

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Questions people ask about E 114

What does E 114 mean on a Lennox furnace?
E 114 means the furnace control board has detected that incoming line voltage frequency is out of the acceptable range and is not registering a proper 60 Hz supply. The furnace shuts down to protect itself from operating on abnormal power. This is typically a power quality issue originating from the utility supply, a generator, or another device in the electrical path feeding the furnace.
How do I fix the E 114 error on my Lennox furnace?
Start by measuring the frequency of the power supply at the furnace using a true-RMS multimeter or power quality meter. If the frequency is abnormal, identify the source, whether that is the utility grid, a generator, or an inverter, and correct the power quality issue. If all external power checks out at a stable 60 Hz and the fault continues, the control board itself may need to be inspected or replaced.
How much does it cost to repair an E 114 error on a Lennox furnace?
If the fault is caused by a utility or generator power quality issue, there may be no parts cost at all, though an electrician or HVAC technician diagnostic visit can range from $75 to $150 or more depending on your area. If the control board has failed and needs replacement, parts and labor combined can range from $300 to $700 or higher depending on the specific board and local labor rates.
Will resetting my Lennox furnace clear the E 114 error?
A manual reset is not required to clear E 114. The furnace is designed to automatically resume normal operation 5 seconds after the fault condition is resolved. If the line voltage frequency returns to a stable 60 Hz, the system will restart on its own without any intervention at the furnace.
Is it safe to run my furnace when it shows E 114?
The furnace will not operate while E 114 is active, which is intentional. Running a furnace on power that deviates from 60 Hz can damage the control board and other electrical components. Do not attempt to bypass the fault. Address the power quality issue first before restoring furnace operation.

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