Tesy water heater shows E10; unit may shut down shortly after start, often associated with dry tank condition.

Safety first: Switch off power immediately if you suspect the element is heating without water. Dry-firing can destroy the element and damage the tank.

Steps:

• Verify water supply: Ensure the cold water inlet valve to the heater is fully open and that there is adequate mains water pressure.
• Bleed air from tank: With power OFF, open a nearby hot water tap fully. Allow water to run until all air sputtering stops and a steady stream flows. This confirms the tank is full.
• Check installation height and piping: Ensure there are no inverted loops or valves that can trap air above the heater.
• Inspect element installation: If the element was recently replaced, confirm it is the correct length and properly seated so that it is fully submerged when the tank is full.
• Reset and test: Restore power and monitor startup. If E10 reappears despite a full tank, the dry-fire detection circuit or sensor on the control board may be faulty and the board should be replaced.

Note: Never energize a Tesy water heater before confirming it is completely filled with water.