Goodman Furnace: Check and adjust temperature rise
Check and adjust temperature rise on a Goodman furnace: Temperature rise depends on airflow and firing rate. An incorrect rise can cause condensing or overheating of the heat exchanger.
Applies to: Gas furnaces ACVC96/AMVC96/GCVC96/GMVC96
Common causes of check and adjust temperature rise
- Too little airflow raises temperature rise. Too much airflow lowers it.
How to fix check and adjust temperature rise: step by step
- Run the furnace with burners firing for about 10 minutes. Do not exceed the nameplate input.
- Make sure all registers are open and duct dampers are in their final positions.
- Place thermometers in the supply and return ducts as close to the furnace as possible, out of direct view of the heat exchanger.
- Allow readings to stabilize, then subtract return air temperature from supply air temperature.
- To reduce temperature rise, increase blower speed. To increase temperature rise, decrease blower speed. See the Circulator Blower Speed section for speed changes.
- Measure motor current draw to confirm the motor is not overloaded.
If the unit shows an error code, look it up: Goodman Furnace codes
Source: Goodman GMVC96 service and troubleshooting manual, p. 47. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.