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Error code reference

Goodman Hvac Error Code 1

Ignition failure, open rollout switch, or open auxiliary limit switch detected by the DSI ignition control…

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Ignition failure, open rollout switch, or open auxiliary limit switch detected by the DSI ignition control module.

First step from the service manual

Check gas flow, gas pressure, gas valve, flame sensor, flame rollout, and auxiliary limit.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 1 means on a Goodman hvac

Error code 1 on a Goodman furnace indicates that the DSI (Direct Spark Ignition) control module has detected one of three conditions: an ignition failure during a heating cycle, an open rollout switch, or an open auxiliary limit switch. The DSI module monitors the ignition sequence and flame signal continuously. If the burner fails to light within the allotted trial period, or if either the rollout or auxiliary limit switch opens during operation, the module locks out and displays this fault code.

Ignition failure is typically traced to insufficient gas supply, low gas pressure, a faulty gas valve, or a contaminated or failed flame sensor. The flame sensor must detect a microamp signal from the burner flame to confirm ignition. If the sensor is coated with oxidation or debris, it cannot pass enough current to satisfy the control module, causing a lockout. Gas pressure should be verified at the manifold to confirm it falls within the furnace's rated operating range.

An open rollout switch indicates that flames have exited the burner compartment in an abnormal direction, typically due to a blocked heat exchanger, restricted flue, or inducer motor failure. An open auxiliary limit switch signals that temperatures in the heat exchanger or plenum area have exceeded safe operating thresholds, often caused by restricted airflow from a clogged filter, blocked vents, or a failed blower motor. Both rollout and auxiliary limit switches are safety devices and should be carefully inspected before being manually reset.

Source: manufacturer service documentation.

Common causes of 1

  1. 01

    Dirty or failed flame sensor

    Wiring / connection

    A flame sensor coated with oxidation or carbon deposits cannot pass sufficient microamp current to confirm ignition, causing the DSI module to time out and lock out. Inspect the sensor rod and clean it with fine steel wool or emery cloth.

  2. 02

    Insufficient gas pressure or gas flow

    Wiring / connection

    Low gas supply pressure or a closed shutoff valve prevents the burners from igniting reliably during the trial period. Verify that the manual gas shutoff is fully open and that manifold pressure matches the furnace rating.

  3. 03

    Faulty or failed gas valve

    Part replacement

    A gas valve that does not open properly or fails electrically will prevent gas from reaching the burners during the ignition sequence. Check for the correct voltage signal at the valve terminals and confirm the valve responds.

  4. 04

    Open rollout switch

    Wiring / connection

    If flames have rolled out of the burner compartment due to a blocked flue, cracked heat exchanger, or failed inducer, the rollout switch opens to prevent a fire hazard. The switch must be manually reset after the root cause is identified and corrected.

  5. 05

    Open auxiliary limit switch due to restricted airflow

    Wiring / connection

    A clogged air filter, blocked return or supply vents, or a failed blower motor can cause excessive heat buildup, tripping the auxiliary limit switch. Check and replace the air filter, clear any vent obstructions, and confirm the blower motor is operating.

See the test procedure for each cause

Frequently asked questions about 1

What does 1 mean on a Goodman hvac?
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.
Can I fix error code 1 on my Goodman furnace myself?
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.
Is error code 1 on a Goodman furnace dangerous?
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.
Will resetting the furnace clear error code 1?
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.
How much does it cost to repair a Goodman furnace showing error code 1?
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.

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