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.