Lennox furnace error code 35

Lennox furnaces are built with safety as a top priority. The diagnostic logic is designed to run automatically after a shutdown and collect data that will help identify the possible cause

You will probably find that the EDRs did not capture enough data to diagnose the problem from their logs, so it’s time to download both logs from the new SD card and upload them for your Lennox Furnace experts for analysis. Any insight on the problem would be great.

Lennox has released a list of error codes for their furnaces that are caused by faulty parts or issues with installation. These codes can help fix the issue with the furnace and identify any potential risks.

The first step is to put the furnace into manual mode so that it doesn’t overheat and shut down again as well as schedule an appointment with the Lennox customer team.

When a diagnosis is complete, basic troubleshooting steps such as cleaning the dryer filter in case it plugs up or restarting the knob to see if the heat will shut off are attempted.

Lennox furnaces use a sensor called a thermistor to measure the igniter voltage. Lennox error code 35 is one of the common errors that occur due to wire breakages in a thermistor assembly.

In Lennox furnace error code 35, the problem is caused due to wire breakage at the connectivity point between resistor and igniter output path (wire breakages do not cover complete length). It can be solved by replacing the broken connection wires.

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