Goodman HVAC Error Code 1

Error code 1 on a Goodman furnace means the DSI ignition control module detected either an ignition failure, an open rollout switch, or an open auxiliary limit switch. These conditions all prevent the furnace from completing a safe heating cycle. The code is the module's way of reporting that the burner did not light successfully or that a safety device tripped during operation.

An open rollout switch is a serious safety condition that means flames have extended outside the burner compartment, which can pose a fire risk. Do not simply reset the rollout switch and restart the furnace without determining why it tripped. An open auxiliary limit switch also signals overheating that should be addressed before continuing operation. Both conditions warrant careful inspection before the furnace is put back into service.

Repair costs vary widely depending on the cause. Cleaning a flame sensor is a low-cost service call, typically in the range of $75 to $150 including labor. Replacing a gas valve is more involved and can range from $200 to $600 or more depending on parts and labor rates in your area. Diagnosing a blocked heat exchanger or flue issue may also reveal additional repairs needed, so costs can vary significantly.

Some causes of error code 1 are DIY-friendly, such as replacing a dirty air filter, cleaning the flame sensor, or checking that the gas shutoff valve is fully open. However, diagnosing a tripped rollout switch, testing gas valve operation, or measuring manifold gas pressure requires proper tools and knowledge of gas appliance safety. If you are not comfortable working with gas components, contact a licensed HVAC technician.

Cycling power to the furnace may temporarily clear the lockout and allow the furnace to attempt another ignition sequence, but the error code will return if the underlying cause has not been resolved. Rollout switches must be manually reset at the switch itself after the cause of rollout has been corrected. Addressing the root cause is necessary for the error to clear permanently.