Ameristar furnaces (built by American Standard Heating and Air Conditioning) are efficient and built to last.
Similar to other top furnace brands like RunTru and AirEase, Ameristar furnaces are equipped with integrated diagnostic systems that display alpha-numeric error codes.
Below is a list of common Ameristar furnace error codes, what they mean, and potential causes.
Please Note: Error codes (and their meanings) can vary between different models. Always consult the documentation specific to your furnace model for accurate information.
| Ameristar Error Code | Meaning | Potential Issue |
| E01 | Loss of IRQ or other internal failures | Control board issue. |
| E2.1 | Retry exceeded (failed to est flame) | Issue with gas valve, gas supply, flame sensor, igniter, etc. |
| E2.2 | Recycles exceeded (establishedFlame lost) or PS open | Faulty wiring, dirty or damaged flame sensor, inconsistent gas flow, etc. |
| E2.3 | Gas valve not energized whenit should be | Worn or damaged gas valve, gas valve switched OFF, wiring issue, etc. |
| E3.4 | Open pressure switch | Blocked airflow, broken pressure switch, issue with pressure switch hose, etc. |
| E04 | Open thermal limit, rollout switch, or reverse airflow switch | Clogged filters, blocked vents, cracked or blocked heat exchanger, etc. |
| E05 | Flame detected when it should not be present | Dirty, damaged or defective flame sensor, gas valve malfunction, electrical issue, etc. |
| E6.1 | Voltage reversed polarity | Issue with line voltage polarity or wiring. |
| E6.3 | (1) Igniter relay fails, or (2) igniter open | Defective flame sensor, bad igniter, dirty filters, gas line issue, etc. |
| E7.1 | Gas valve (MVL) energized when it should be off | Gas valve stuck open, damaged or dirty flame sensor, wiring issue, etc. |
| E08 | Flame current low (still strong enough for operation) | Dirty, damaged or faulty flame sensor, low gas pressure, etc. |
| E09 | Open inducer limit switch or condensate pressure switch | Blocked condensate drain, blocked vents, faulty pressure switch, etc. |
| E12 | Open fuse | Warn, dirty or faulty furnace components, low airflow, wiring issue, other. |
