Armstrong Furnace Repair Guide
What’s Wrong With Your Armstrong Furnace?
| Is your furnace... | The problem might be your... | What's wrong? | How you can fix it: |
|---|---|---|---|
| Not heating? | Circuit Breaker/Fuse | Most likely, either the electrical system providing your furnace’s power has shorted or the power switch has blown. | Try resetting your furnace’s circuit breaker. If it has blown, you will need to replace it. |
| Igniter | The furnace’s igniter might either be cracked or faulty. | Check the part for cracks, if it is then replace the igniter. If it isn’t cracked, use a multimeter to test for continuity. | |
| Cycling irregularly? | Thermostat | Your thermostat might be adjusting incorrectly, causing the furnace to cycle on and off too often. | If your thermostat has an adjustable calibration scale, adjust the heat anticipator. If this does not stabilize the unit, you may have to replace the thermostat. |
| Not blowing hot air? | Blower Motor | Your blower motor may have completely burnt out. If this doesn’t seem to be the case, then the connecting belt may have simply broken. | Test to see if power is reaching the motor. If it does, but isn’t running, the motor has likely failed. If the motor runs but air doesn’t move, the connecting belt has probably broken. You’ll have to replace the belt. |
| Blowing too much air? | Control Board | The control board regulates the amount of voltage that reaches each functioning part. If the relay that controls the blower motor has failed, it will continually send voltage to the motor. | Replace the control board. |
| Thermostat | The contact that controls the blower motor on your thermostat may be stuck closed, causing the blower motor to run continuously. | Use a multimeter to check for continuity. If it appears the thermostat is the issue, replace it. | |
| Leaking water? | Drain Pipe | ||
| Starting and then stopping shortly after? | Flame Sensor | Your furnace’s flame sensor monitors the burner, detecting whether a flame is present. If it is either defective or dirty, it will not be able to detect a flame. | If dirty, clean the sensor using a fine abrasive pad. If faulty, replace the flame sensor. |
How to Replace Your Air Filter
- Locate the access panel and remove it or slide it open
- Look near the cold air intake to find the filter
- Remove the old filter
- Align the new filter by following the arrows
- Slide in the new filter
- Close the access panel
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Armstrong Furnace Error Codes
| Armstrong Error Code | What this means |
|---|---|
| LED is on and not flashing | The furnace is operating normally |
| Single LED flash | Flame continues to burn when the gas is off |
| Two LED flashes | Problem with the pressure switch |
| Three LED flashes | Problem with the pressure switch |
| Four LED flashes | Problem with the high limit switch |
| Five LED flashes | Problem with the rollout switch |
| Six LED flashes | Problem with the pressure switch |
| Seven LED flashes | Problem with the ignitor |
| Eight LED flashes | The flame is dropping |
| Nine LED flashes | Problem with the voltage |
When to call a professional to repair your Armstrong furnace
Who Should You Call?
Armstrong’s Warranty Coverage
Armstrong Furnace Model Numbers
Discontinued Armstrong Furnace Models
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