Lennox furnace error code 700

There are various reasons why Lennox furnaces can trigger error code 700.

The furnace is not displaying necessary control system software when installed or the installation has been completed after 2010 or the software on the furnace needs to be updated

The first case to analyze comes from older Lennox models. Manufacturers introduced new circuit boards for these types of equipment in 2010. The boards made 10 common error codes disappear and replaced them with 18 different ones.

Lennox error code 700 suggests that the fan is not working as a result, the combustion process is interrupted as it can’t extract heat and fresh air. The operator service panel must be inspected to resolve the problem

To resolve Lennox Error Code 700, you will have to inspect if the fan blower functions by using test buttons or knobs on the front and back of your furnace. One can also check for any malfunctioning fan blades. Inspecting fans and blades can be a somewhat challenging task which might take longer than usual because some people use boards and covers on them when these are not required so that they fix it quickly whenever they stop working.

Dangerous surroundings can be one of the causes for this error code 700 which means that there could be excess carbon monoxide in your home.


“Inspections, Installations, Repairs & Maintenance”