Lennox HVAC Error Code 205

Error code 205 on a Lennox HVAC system means the indoor blower motor has overheated and tripped its internal thermal protector. The protector is a built-in safety device that shuts the motor down before winding damage can occur. The fault clears automatically once the blower demand is satisfied and the motor cools, but the underlying cause must be diagnosed. Lennox specifies checking motor bearings and amp draw as the first diagnostic step.

You should not continue operating the system without addressing the cause of code 205. The internal protector is designed to prevent motor fire and winding damage, and repeated thermal trips accelerate motor deterioration. Running the system while the fault is active or recurring can lead to complete motor failure and, in worst-case scenarios, a fire risk from sustained overheating.

Repair cost depends on the root cause. If the fix is simply replacing a clogged filter or clearing an airflow restriction, the cost is minimal, typically under $30 for parts. A run capacitor replacement generally falls in the $75 to $200 range including labor. If the blower motor itself needs to be replaced, costs typically range from $300 to $700 or more depending on the motor specifications and local labor rates.

The fault associated with code 205 clears on its own after the blower demand condition is satisfied, so a manual reset is not required. However, simply waiting for the code to clear does not fix the problem. If the bearing wear, high amp draw, or airflow restriction causing the overheat is not corrected, the motor will trip again during the next run cycle.

Start by checking the air filter and replacing it if it is dirty, then inspect the return grilles and evaporator coil for blockages. Next, measure the motor's amp draw with a clamp meter and compare it to the nameplate rating. Check the bearings by manually spinning the blower wheel with power off; any stiffness or grinding indicates bearing failure. If bearings are worn, amp draw is high, or the motor trips repeatedly under normal conditions, the motor should be replaced.