Lennox Furnace Error Code E229

E229 indicates the furnace performed an ignition at high fire speed rather than the standard low fire startup. It is classified as an informational code, not a lockout fault. It occurs either because the low pressure switch did not close during low speed inducer operation, prompting the board to switch to high speed, or because the continuous fan was running when a heating call began, which triggers a 60-second high fire startup by design.

E229 is not a safety lockout and does not indicate a dangerous condition by itself. The furnace remains operational when this code is logged. However, if the code is appearing because the low pressure switch is not functioning correctly, the underlying cause should be diagnosed and resolved to ensure the combustion air system is performing within its designed parameters.

Repair costs depend on the root cause. Pressure switch tubing replacement or a flue cleaning is generally low cost, typically in the range of $75 to $200 including a service call. Replacing a faulty low pressure switch usually falls in the $150 to $350 range for parts and labor. Inducer motor replacement is more involved and can range from $400 to $800 or more depending on the specific unit and labor rates in your area.

Start by determining whether the continuous fan setting is active on your thermostat, as that alone explains the code without requiring any repairs. If continuous fan is not active and E229 appears on every heat cycle, inspect the pressure switch tubing for cracks or blockages, check the pressure switch itself for proper operation, and evaluate the inducer motor for signs of wear. Clearing any flue or condensate drain restrictions should also be part of the diagnostic process.

Resetting the furnace may clear the code temporarily, but if the low pressure switch is faulty or there is a restriction in the pressure tubing or flue, E229 will return on the next heating cycle. If continuous fan mode is the cause, the code will reappear each time a heating call starts while that mode is active, which is normal. A reset alone does not address any underlying component issues.