Goodman furnace A: Airflow display, followed by the CFM value
A is not a fault. It introduces an airflow reading — the furnace is telling you the CFM it is currently delivering, with the value following on the display.
Applies to: Goodman GMVM97 and GCVM97 modulating gas furnaces with a two-character alphanumeric display.
What it means
Goodman's modulating furnaces can display live operating data as well as faults, and A introduces airflow. The display shows A and then the cubic feet per minute the blower is delivering, given as the left two digits of the value. This is genuinely useful information rather than a problem report: it lets a technician confirm the furnace is achieving its designed airflow without instruments, and it lets a curious owner see how the blower varies between heating, cooling, and continuous fan. Mistaking it for a fault code is the main risk, which is why it is worth documenting.
Most common causes
- Not applicable — this is an operating data display rather than a fault.
How to diagnose it
- Recognise that this is data rather than a fault. The furnace is reporting, not complaining.
- Note the value that follows the A, since that is the actual information.
- Compare the airflow against what the furnace should deliver for the mode it is in, which is in the specification for the model.
- Note that a value well below expected accompanies the low airflow fault code, which is the fault version of the same observation.
How to fix it
- Nothing to fix. This is the furnace displaying its own operating data.
- If the airflow value looks low, check the air filter and registers — that is the usual cause and it is homeowner work.
- If airflow is consistently below specification with a clean filter and open registers, the duct system is worth assessing.
- Use this reading rather than guessing when discussing airflow with a technician.
Notes
A furnace that will tell you its own airflow is unusual and worth taking advantage of. Most airflow problems are diagnosed by inference; here the equipment simply reports the number.
Related
All codes for this manufacturer
Goodman and Amana furnace fault codes — every code, with what differs between models.
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.
What the fix costs
The A readout is free information, and most of what it leads to is cheap. A low CFM value traced to a clogged filter costs the price of the filter; opening closed registers costs nothing. The expensive branches: if low airflow readings arrive together with the b-code blower faults, blower work on these furnaces means ECM money — $700–1,200 installed for a standard ECM, $900–1,500+ for the variable-speed motors these models carry, per the blower motor cost guide — and duct corrections, where an assessment finds the system genuinely restrictive, are quoted case by case. A visit to run that assessment starts at a $75–150 diagnostic (repair cost guide).
DIY or call a pro?
Reading the display, noting the CFM value in each operating mode, and changing the filter are exactly the homeowner jobs this feature was built for — no panel needs to come off. The professional line sits where the number stays low with a clean filter and open registers: static-pressure testing, duct modification, and blower diagnosis are technician work, and on a variable-speed system a wrong guess is a four-figure part. Bring the recorded values to the visit; a technician who arrives already knowing what the furnace reports for its own airflow starts an hour ahead.
What this looks like
From the outside, this usually shows up as there is no heat but nothing looks obviously wrong — that walkthrough covers what to check in order, and when it stops being a homeowner job.