Ruud Error Code 13: Improper Combustion
How to Fix Ruud Code 13
- Step 1: Immediately shut off the furnace at the breaker.
- Step 2: Ensure you have working carbon monoxide detectors in your home, especially near sleeping areas. If you don't have them, install them immediately.
- Step 3: Open windows and doors to ventilate your home.
- Step 4: Call a qualified HVAC technician to inspect and repair the furnace. Do not attempt to restart the furnace until it has been inspected.
How to Reset Ruud Code 13
- Turn off the furnace power switch, usually located on or near the unit.
- Turn off the circuit breaker for the furnace. Wait 30 seconds.
- Restore power at the breaker and flip the furnace switch back on.
- Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.
What does 13 mean?
Ruud error code 13, 'Improper Combustion,' means the furnace isn't burning fuel correctly. This can happen for several reasons, but the most important thing is that it could lead to a dangerous buildup of carbon monoxide (CO) in your home. CO is a colorless, odorless gas that can be deadly. The furnace's control board constantly monitors the flame and exhaust to ensure proper combustion. When it detects a problem, it shuts down the furnace and displays this error code to prevent further risk.
Specifically, the system is likely detecting either a weak flame, a flame that's not properly established, or excessive carbon monoxide in the exhaust gases. This could be due to a gas supply issue, a problem with the burner, or a venting problem that's preventing the exhaust gases from escaping your home. Because of the safety risks involved with improper combustion, it's important to have a qualified technician diagnose and repair the problem as soon as possible.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Flame Sensor | 41-401 | — |
| Gas Valve | 7061173 | — |
| Pressure Switch | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 11 | No Ignition | Critical |
| 12 | Flame Failure | Critical |
| 14 | Overheat / Thermal Fuse | Critical |
| 15 | Inlet Temp Sensor Fault | Warning |
| 16 | Outlet Temp Sensor Fault | Warning |
| 21 | Air Supply / Operational Switch | Warning |
| 24 | Flow Sensor Malfunction | Warning |
| 29 | Condensate Neutralizer Issue | Warning |
| 31 | Inlet Water Filter | Warning |
| 33 | Fan Motor Fault | Warning |