Goodman/Amana Furnace Fault Codes Guide
Goodman and Amana furnaces are built on the same platform — Goodman Manufacturing produces both brands, so their control boards and fault code systems are identical. Whether you own a Goodman GMVC96, GMSS96, Amana AMVC96, or another model in these families, this guide will help you interpret the LED flash codes on the control board and decide on your next step. Goodman and Amana furnaces are among the most widely installed in Milwaukee-area homes, and understanding their fault codes can mean the difference between a quick self-service fix and an unnecessary emergency call.
How to Read Goodman/Amana Flash Codes
The status LED on Goodman and Amana furnaces is located on the main control board inside the blower compartment. It blinks a set of flashes, pauses, then blinks again. The number of flashes in the first set is the primary fault code; the second set is the secondary code on some models. A label inside the furnace door lists the fault descriptions for your specific model — always check this label first. On ComfortNet communicating systems, codes appear on the connected thermostat display and are logged for technician review.
Before reading a fault code, make sure you are counting from the beginning of a sequence. The LED may already be mid-sequence when you begin watching. Watch for two complete sequences to confirm the count. Write down the code before resetting the furnace — on standard LED systems, a power cycle clears the active code from display.
Common Goodman/Amana Furnace Fault Codes
| Flash Code | Meaning | What to Do |
|---|---|---|
| 1 flash | System lockout — ignition failure (3 tries) | Check gas supply; one reset allowed |
| 2 flashes | Pressure switch stuck open | Check vent blockage and condensate drain |
| 3 flashes | Pressure switch stuck closed | Technician required |
| 4 flashes | Open high-limit device — overheating | Replace filter; check airflow |
| 5 flashes | Flame sense with no call for heat | Technician required — gas valve issue |
| 6 flashes | 115V polarity or grounding issue | Licensed electrician required |
| 7 flashes | Low flame signal — dirty flame sensor | Clean flame sensor; call if issue persists |
| 8 flashes | Ignitor fault — no heat detected from ignitor | Technician required — ignitor replacement |
| 9 flashes | Rollout switch open | Shut off furnace immediately; call for service |
| Slow flash (green) | Normal standby / no call for heat | No action needed |
Pressure Switch Codes (2 Flashes): Milwaukee Cold-Weather Context
Goodman and Amana high-efficiency furnaces — the GMVC96, GMSS96, and similar 96% AFUE models — are particularly prone to pressure switch errors in cold weather. These units are the most commonly installed Goodman furnaces in new Milwaukee homes and in energy upgrade replacements over the past 15 years. When outdoor temperatures drop sharply, two issues account for the vast majority of 2-flash service calls in the Milwaukee area:
Blocked flue vent: The PVC intake and exhaust pipes that exit through an exterior wall can become blocked by ice, snow, or debris. Check the termination points on the outside of your home and clear any obstructions carefully. Never use sharp tools or open heat sources near PVC vent pipe. Warm water applied carefully at the ice blockage point is the safest approach. This failure mode is especially common during Milwaukee's February and March cold snaps, when nights drop below 0°F.
Clogged condensate drain: High-efficiency furnaces pull so much heat from combustion gases that those gases condense into water — 1–3 gallons per day during heavy heating use. This water drains through a tube to a floor drain or condensate pump. If the drain line clogs (from scale, algae, or debris) or freezes (if routed through an unheated space), it backs up and mimics a pressure switch failure. A wet/dry vacuum applied at the condensate drain outlet can often clear a soft clog without a service call.
Flame Sensor Cleaning (7 Flashes): A Milwaukee DIY Fix
The flame sensor is a small metal rod that extends into the burner flame on Goodman and Amana furnaces. Its function is to confirm that the gas valve has successfully ignited by detecting the small electrical current that flows through the flame. Over time, the sensor develops a white oxide coating that reduces its conductivity below the safe detection threshold, causing the furnace to report a low or absent flame signal and shut down.
Goodman and Amana flame sensors are straightforward to access and clean:
- Turn off the furnace at the thermostat and the power switch
- Locate the flame sensor — a small bent metal rod with a single wire connector, positioned in the burner assembly
- Remove the one or two screws holding the sensor bracket
- Slide the sensor out and lightly rub the metal rod with fine steel wool or a dollar bill — avoid sandpaper, which leaves abrasive grit on the sensor
- Reinstall and test with a heating call
If the 7-flash code returns after cleaning, the sensor likely needs replacement — a straightforward technician repair. Burkhardt carries common Goodman and Amana flame sensor replacements on all service vehicles.
High-Limit Faults (4 Flashes) in Milwaukee Homes
The 4-flash high-limit code is Goodman and Amana's indication that the heat exchanger has overheated to the point of triggering a safety shutoff. The overwhelming cause is restricted airflow from a clogged air filter. Goodman recommends checking filters every 30 days during peak heating season — a schedule that is realistic given Milwaukee's 6-month heating season and the amount of time these furnaces run each day from November through April.
Replace with the correct filter size and a MERV rating the system was designed for. High-MERV filters (MERV 13+) increase airflow restriction and can themselves cause high-limit trips on systems designed for lower-restriction filters. Also verify that all supply registers throughout the home are open and unobstructed — closing registers in unused rooms is counterproductive and can cause high-limit faults on properly sized systems.
When to Call a Professional for Goodman/Amana Issues
Rollout switch faults (9 flashes) mean flames escaped the heat exchanger. This is a fire and carbon monoxide hazard. Do not reset the furnace — turn it off at the thermostat, open windows, and call for emergency service. Rollout switch trips can indicate a cracked heat exchanger, which is a safety-critical component requiring immediate professional evaluation.
Flame-sensed-without-call codes (5 flashes) suggest the gas valve is not closing properly, allowing gas to flow and ignite without a thermostat demand. This requires professional diagnosis and should not be operated until repaired.
Burkhardt Heating has been servicing Goodman and Amana equipment across southeastern Wisconsin for decades. Our NATE-certified technicians know these systems inside and out and carry common repair parts — control boards, igniters, flame sensors, pressure switches — on every service vehicle throughout the Milwaukee metro area.
Frequently Asked Questions About Goodman/Amana Furnaces in Milwaukee
Why does my Goodman furnace show 2 flashes every winter but not in fall?
Winter-specific 2-flash codes on high-efficiency Goodman furnaces almost always indicate vent icing. As Milwaukee temperatures drop below 0°F, the PVC vent termination on the exterior wall can ice over, blocking airflow and tripping the pressure switch. Check the exterior vent location and carefully remove ice with warm water. A technician can install cold-climate vent termination upgrades to prevent seasonal recurrence.
Is the Goodman GMVC96 or GMSS96 a good furnace?
Both are reliable units with strong track records in Milwaukee's climate. The GMVC96 is a variable-capacity model that adjusts output based on demand — more efficient and quieter in operation. The GMSS96 is a two-stage model at a lower price point. Both offer 96% AFUE, which meets Wisconsin Energy Code requirements for gas furnace replacements.
How do I find a Goodman service manual for my specific model?
Goodman Manufacturing publishes installation and service manuals on their website at goodmanmfg.com. The model number is on the data label inside the blower compartment door. Your Burkhardt technician also has access to Goodman's dealer service documentation for all current and recent models.
Does Burkhardt install Goodman and Amana replacement furnaces?
Yes. Burkhardt installs Goodman and Amana equipment for Milwaukee-area homeowners seeking a cost-effective replacement option. We can also evaluate whether a like-for-like Goodman replacement or an upgrade to a different product line makes more sense based on your home's specific heating needs. Call (414) 355-5520 for a no-obligation assessment.
Goodman/Amana Furnace Repair Near You
Fault codes are designed to protect your equipment and your family. Addressing them promptly — before the furnace fully locks out on the coldest night of the year — is always the right call. For comprehensive furnace and HVAC resources, see our Milwaukee boiler repair guide and our overview of ductless mini split systems as supplemental heating options for Milwaukee homes.
If you see any of these codes, call Burkhardt at (414) 355-5520. Our NATE-certified technicians can diagnose and repair the issue — usually in a single visit.
Ready to schedule service? Call Burkhardt Heating, Cooling, Plumbing & Electric at (414) 355-5520 or contact us online. Available 24/7 for emergencies.
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