Boiler displays E05 and will not fire; may indicate low water pressure or low water cutoff

Safety: Do not run the boiler with low water; this can damage the Crown heat exchanger. Allow the system to cool before adding water.

• Check pressure gauge: Read the boiler pressure gauge. If below the recommended cold fill (often around 12 psi), the system needs water.
• Verify automatic fill valve: Locate the pressure reducing valve (auto-fill) on the cold water supply to the boiler. Ensure the shutoff valve ahead of it is open. If equipped with a fast-fill lever, briefly lift it to add water while monitoring the pressure gauge. Do not exceed 25 psi.
• Inspect for leaks: Walk the piping, radiators, and baseboards looking for visible leaks or dripping relief valves. Repair leaks before refilling repeatedly.
• Check low water cutoff (if fitted): Some Crown boilers have an external low water cutoff. Ensure its wiring is intact and the device is not manually tripped (if it has a reset). Only reset once after confirming proper water level.
• Reset boiler: Once pressure is restored and stable, reset the boiler. If E05 persists, the pressure sensor or low water cutoff may be faulty and should be tested by a technician.