Furnace Fault Codes

Goodman furnace 11 red flashes: Limit switch open due to blower failure

Eleven red flashes means the limit switch opened and the control has attributed it to the blower rather than to airflow restriction. The furnace overheated because the blower did not move air.

This code is not a homeowner repair. Faults in this group involve the gas valve, the burner compartment, or the heat exchanger — the parts whose failure can put combustion products, including carbon monoxide, into the air the house breathes. Do not reset it repeatedly to keep the heat on. Have it looked at by a licensed technician, and make sure there is a working carbon monoxide alarm on every level of the home, including the level the furnace is on. The conditions that mean stop now.

Applies to: Goodman GMEC96 and Amana AMEC96 two-stage gas furnaces with a three-colour diagnostic LED.

What it means

This code is more specific than a plain open limit switch, and the extra specificity is useful. The control has seen the limit open and has determined the blower is the reason — it was commanded to run and either did not, or did not deliver. That distinguishes it from the four red flash code, where the limit opened for reasons that could include a dirty filter, closed registers, or ductwork. Here the control is pointing at the blower itself, which narrows the investigation to the motor, its power, and its control circuit.

Most common causes

How to diagnose it

  1. Note whether the blower runs at all — on a fan-only thermostat setting, or during cooling. A blower that runs in one mode and not another points at the control circuit rather than the motor.
  2. Check the blower door is properly seated, since the door switch cuts power and a door not closed produces confusing symptoms.
  3. Listen at the start of a heating cycle for the blower attempting to start.
  4. Note whether the furnace fires and then shuts down shortly afterwards, which is the sequence this code describes.

How to fix it

  1. Refit the blower door properly if it was not seated.
  2. Everything else is technician work — the blower motor, capacitor, relay, and wiring all sit in the high voltage side of the furnace.
  3. Do not run the furnace in heat with a blower that is not working. The limit will stop it, but repeatedly overheating the heat exchanger is what cracks it.
  4. Have the cause of any obstruction established rather than just cleared, since something that got into the blower once can get in again.

Notes

A furnace that fires briefly and then shuts down, repeatedly, with no heat reaching the house is the usual presentation. The heat exchanger is being heated with no air moving over it each time, which is precisely the condition the limit switch exists to stop.

Related

All codes for this manufacturer

Goodman and Amana furnace fault codes — every code, with what differs between models.

Not sure this is your brand?

The same count means something else on other furnaces. What 11 flashes means on every brand puts them side by side.

Models this code appears on

From the manufacturer's per-model database. If your model is not listed, this code may not exist on your board, or it may mean something different — check the model page.

The same fault on other control families

Most limit-switch codes cannot tell you why the furnace overheated; this one can, and that specificity is preserved across the shared table — York's eleven red flashes matches it almost word for word, attributing the open limit to blower failure rather than general airflow restriction. The limit switch code hub covers the broader overheat family and its usual message that the switch is almost never the real fault; this code is the variant where the control has already named the real fault for you.

What the fix costs

Because the control has fingered the blower, budget from the blower motor cost guide: $400–700 installed for a PSC motor, $700–1,200 for an ECM, $900–1,500+ for variable-speed — which motor your furnace carries decides the band. The guide's standing advice matters most here: a PSC blower that hums but will not spin very often has a failed $15 capacitor, a $150–350 fix, and any honest quote for a dead blower should mention that test. The limit switch itself, having done its job, rarely needs replacing — be sceptical of paying the $150–350 switch price on top unless it genuinely failed.

DIY or call a pro?

Note the nuance before reaching for the usual advice: on the general overheat code the first move is the filter, but this code says the blower did not run — a clean filter will not fix a motor that never spun. The safe homeowner observations are aural: on a call for heat, does the blower attempt to start, hum, squeal, or stay silent? Report that. Hands stay out because blower circuits are line voltage and capacitors hold their charge after the power is off — the classic homeowner injury on this exact fault. If burners light and the blower stays silent, switch the furnace off rather than letting it cycle on the limit switch while you wait for the visit.

What this looks like

From the outside, this usually shows up as the furnace heats then trips out on high limit — that walkthrough covers what to check in order, and when it stops being a homeowner job.

Sources

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.