If the red LED behind your Goodman furnace's blower door is blinking a steady, repeating count, the control board is handing you a diagnostic code — count the flashes between the pauses and that number tells you why the furnace shut the burners down. Goodman and Amana furnaces share the same control boards, so the same blink chart applies to both. Good to know up front: a steady, solid red light is normal — it means the board has power and is simply waiting in standby. It's a rhythmic count that points to a fault.
Reading the code: watch one full cycle. The LED flashes a set number of times, pauses, then repeats — four flashes, pause, four flashes is a 4-flash code, and so on. Flash-code meanings can vary by control-board generation, so always confirm the count against the diagnostic label printed inside your furnace's blower compartment. Newer Goodman/Amana ComfortBridge boards drop the blink count and show a 2-digit numeric code instead — read those directly off the module or label.
Goodman red-light blink codes
| Code | Meaning | Typical cause |
|---|---|---|
| 1 flash | Ignition failure lockout (after 3 failed tries) | Dirty or failed flame sensor, weak/cracked hot-surface igniter, gas-supply problem |
| 2 flashes | Pressure switch stuck closed | Switch contacts stuck closed when they should be open, or a wiring/hose fault |
| 3 flashes | Pressure switch stuck open / won't close | Blocked flue or vent, weak/failing inducer (draft) motor, clogged condensate on high-efficiency models, disconnected hose |
| 4 flashes | Primary limit switch open / over-temp | Dirty filter, blocked return, closed vents, failed or slow blower motor |
| 5 flashes | Flame sensed with no call for heat | Stuck-open gas valve, or a flame-sensor/board fault |
| 6 flashes ⚠ | Flame rollout / auxiliary limit open (board-dependent) | Rollout from a blocked heat exchanger or poor venting — but the meaning of a 6 varies by board generation; verify on the unit |
| 7 flashes | Low flame-sense signal | Dirty flame sensor, low gas pressure, poor burner ground |
| 8 flashes | Igniter circuit fault | Open or failed hot-surface igniter or its wiring |
| 9 flashes ⚠ | Reversed line polarity / grounding fault (board-dependent) | Hot and neutral reversed at the outlet or wiring, or a missing ground — meaning varies by board generation; verify on the unit |
| Steady ON | Normal standby | No fault; the board has power and is waiting for a call for heat |
A note on the 6 and 9 codes: these two are the ones that most often shift meaning between board generations. Older and newer Goodman/Amana boards do not always assign 6 flashes and 9 flashes to the same fault. Where the chart above and the label inside your furnace disagree, the label on your specific unit wins — verify it before you buy any part.
What the codes are really telling you
Most Goodman blink codes fall into three buckets:
- Airflow (4 flashes). The furnace overheated because air isn't moving — nearly always a dirty filter, a blocked return, or a tired blower. This is the most DIY-friendly of the group.
- Venting / pressure (2 and 3 flashes). The pressure switch confirms the inducer is drawing combustion gases safely out. A 3 usually means the switch never closed — blocked vent, weak inducer, or a clogged condensate trap on high-efficiency furnaces.
- Ignition / flame (1, 5, 7, 8 flashes). These center on the igniter, the flame sensor, and the gas valve. A 1-flash lockout after three tries and a 7-flash low-flame-signal both frequently trace back to a dirty flame sensor — a small, cheap part.
Common causes
In order of how often we find them behind a blinking Goodman:
- Dirty air filter — the #1 cause of a 4-flash over-temp lockout.
- Dirty flame sensor — the usual reason for a 1-flash lockout or a 7-flash weak-flame code.
- Blocked intake/exhaust or clogged condensate trap — behind most 3-flash pressure-switch faults.
- Weak or failing inducer (draft) motor — a deeper 3-flash cause.
- Failed hot-surface igniter — no ignition, often paired with the 1 or 8 code.
- Aging control board — less common, but it can misreport or lock out.
The usual fix
Our tech reads the stored code, then confirms it rather than trusting the number alone: check and change the filter, clean or replace the flame sensor, verify the inducer and vent draw properly, test the pressure switch and limit, and inspect the igniter and gas pressure. Many blinking-Goodman calls end with a cleaned flame sensor or a fresh filter; when a part has genuinely failed we replace it and confirm the furnace completes a full heat cycle without re-flashing.
DIY vs. calling a pro
Safe to try yourself first (free):
- Turn the furnace off and change a dirty filter, then give it 20–30 minutes and restart — this clears a large share of 4-flash codes.
- Open blocked supply and return vents and clear anything stacked over a return.
- Power-cycle at the switch or breaker to reset a soft lockout after you've fixed airflow.
Call a pro when:
- The code comes right back after a fresh filter (1, 3, 7, or 8 especially).
- You see a 6 or 9 — these touch rollout and line-voltage wiring and should be verified on the unit, not guessed at.
- The furnace locks out with no heat, or you smell a hot/burning odor.
Gas, line-voltage electrical, and any refrigerant or compressor work belong with a licensed technician (EPA 608 certified for refrigerant handling) — a furnace that keeps overheating or rolling out can crack the heat exchanger, which is a carbon-monoxide risk.
What it costs in the Bay Area
Many blinking-red-light fixes are inexpensive because the cause is airflow or a dirty sensor. When a part is needed, in our pricing a flame sensor runs about $90–$250, a hot-surface igniter $120–$350, a control board $200–$600, and a blower motor $400–$700, depending on model. We charge a diagnostic fee that's credited toward the repair when you approve the work, and you get a firm, upfront price before anything is done.
Book Goodman furnace service
Triton services Goodman and Amana furnaces — plus every major brand — across the SF Bay Area & Peninsula, with same-week and often same-day appointments. If your Goodman is stuck blinking a code, we'll read it correctly and get your heat back.
Call (888) 993-5699 or book online for same-day furnace service.
Related pages
- HVAC Repair in the SF Bay Area — our full heating & cooling hub
- Furnace Not Heating / No Heat — the symptom behind a lockout
- Furnace Short Cycling (On and Off) — overheating that cycles
- Goodman / Amana HVAC Repair — brand service hub
- Furnace Repair in Hayward — same-day service in your city
Frequently asked questions
What does a blinking red light on my Goodman furnace mean? A repeating count of red flashes is a diagnostic code — the number of flashes between pauses identifies why the furnace shut down. A steady, solid red light is normal standby, not a fault. Goodman and Amana furnaces share the same boards, so the same chart applies to both.
How do I read a Goodman furnace blink code? Watch one full cycle through the sight glass: the LED flashes a set number of times, pauses, then repeats the same number. Four flashes, a pause, four flashes is a 4-flash code. Then confirm that number against the diagnostic label inside the blower door, because meanings vary by board generation.
What does 4 flashes mean on a Goodman furnace? Four flashes is an open primary limit / over-temperature trip: the furnace got too hot inside because air wasn't moving. The usual causes are a dirty filter, blocked returns or vents, or a weak blower. It's the most DIY-friendly code — start with a fresh filter and open vents.
What causes 3 flashes on a Goodman furnace? Three flashes means the pressure switch didn't close, so the board won't let the burners light. Common causes are a blocked intake or exhaust vent, a weak inducer motor, a clogged condensate trap on high-efficiency models, or a disconnected pressure-switch hose. This one usually needs a tech.
Why does my Goodman furnace lock out on 1 flash? One flash is an ignition-failure lockout after three failed tries. It most often traces to a dirty or failed flame sensor, a weak hot-surface igniter, or a gas-supply issue. Cleaning the flame sensor clears many of these, but persistent lockouts should be checked by a technician.
How much does Goodman furnace repair cost in the Bay Area? Many fixes are inexpensive because the cause is a filter or a dirty flame sensor. When a part is needed, a flame sensor runs about 90 to 250 dollars, a hot-surface igniter 120 to 350 dollars, a control board 200 to 600 dollars, and a blower motor 400 to 700 dollars. We credit the diagnostic fee toward the repair and quote a firm price first.