Furnace does not respond to thermostat; E06 displayed on control board or interface.

Safety: Turn off power before working on low-voltage wiring to avoid shorting the transformer.

• Check thermostat: Verify the thermostat is set to HEAT and the setpoint is above room temperature. Replace batteries if applicable. Confirm the thermostat is compatible with a Wolf furnace (standard 24V, not line-voltage).
• Inspect wiring: Remove the thermostat from its base and inspect the R, W, C (and other) wires. Ensure they are firmly attached and not shorted together. At the furnace control board, verify the thermostat wires are secure on the R, W, Y, G, C terminals.
• Test heat call: With power off, temporarily jumper R to W at the Wolf control board. Restore power. If the furnace starts normally, the issue is likely with the thermostat or thermostat cable. If E06 persists, the problem may be with the transformer or control board.
• Transformer check: A qualified person can measure 24VAC between R and C at the control board. If no voltage is present, the Wolf 24V transformer may be failed and should be replaced.