The status LED is solid green; the furnace appears to have power but does not respond to the thermostat; there is no inducer or blower operation.

Safety first: Turn off power before handling low-voltage wiring to avoid shorting the control board.

Steps to check:

• Check thermostat settings: Ensure the thermostat is set to HEAT and the setpoint is above room temperature. Replace thermostat batteries if applicable.
• Inspect low-voltage fuse: Locate the 3–5 amp automotive-style fuse on the Coleman control board. If blown, replace it with the same rating. If it blows again immediately, there is a short in the low-voltage circuit that must be found.
• Test R to W call: With power off, remove the thermostat wires from R and W at the furnace. Restore power and temporarily jumper R to W at the control board. If the furnace starts, the issue is in the thermostat or thermostat wiring.
• Inspect thermostat cable: Look for staples driven too tightly, damaged insulation, or splices that may have come loose. Repair or replace damaged cable.

If the furnace does not respond even when R and W are jumpered, the control board may be faulty and should be tested by a technician.