Boiler shows E06; may indicate supply temperature sensor error

Safety: Turn off power to the Crown boiler before accessing the control compartment.

• Locate supply sensor: On most Crown boilers, the supply temperature sensor (NTC) is clipped or threaded into the supply outlet pipe or heat exchanger manifold. Consult the boiler's wiring diagram on the inside panel.
• Inspect wiring: Check the sensor leads for cuts, abrasions, or signs of overheating. Ensure the plug at the control board is fully seated and free of corrosion.
• Check sensor mounting: Make sure the sensor is firmly in contact with the pipe or properly inserted into its well. A loose sensor can read incorrectly.
• Dry moisture: If there is any sign of water leakage around the sensor, dry the area and correct the leak. Moisture can cause shorts.
• Reset and test: Restore power and reset the boiler. If E06 returns, the NTC sensor is likely defective and should be replaced with a Crown-approved part.