Carrier 58MVC Error Code LED Continuous ON: Control Has 24 VAC Power
What Does Code LED Continuous ON Mean?
When the amber LED on the control board is continuously ON (solid, not flashing), the furnace control has 24 VAC power and is operating normally in standby mode. There is no call for heat from the thermostat, so the furnace is simply waiting. This is the status you should see when the furnace is powered on but not actively heating.
This is the normal, healthy resting state for your 58MVC. If you see this LED pattern during a time when you expect the furnace to be heating, the issue is most likely with the thermostat or thermostat wiring rather than the furnace itself. Check that your thermostat is set to "Heat" mode, the set temperature is above the current room temperature, and the batteries (if applicable) are fresh.
In a properly functioning system, when the thermostat calls for heat (closes the R-W/W1 circuit), the LED will begin flashing a status code as the furnace starts its ignition sequence. If the LED stays solid despite the thermostat calling for heat, the signal may not be reaching the furnace control.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Normal standby condition - no thermostat call | ✓ DIY fix → | |
| Thermostat not calling for heat | ✓ DIY fix → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The furnace won't respond to the thermostat despite showing a solid LED (code-on)
- The thermostat is calling for heat but the furnace remains in standby
- You've replaced the thermostat batteries and verified settings but the furnace still won't start
- The thermostat display shows it is calling for heat but nothing happens at the furnace