Reliance water heater shows E10 and shuts down, often accompanied by gurgling or boiling sounds

Safety first: Turn OFF power and gas immediately. Operating a water heater without water can severely damage the unit.

Steps to check:

• 1. Confirm water flow: Open several hot water faucets. If little or no water flows, the tank or heat exchanger is not full. Check that the cold water shutoff to the heater is fully open.
• 2. Purge air (tankless): With the cold inlet open and power OFF, open hot water taps until a steady stream (no sputtering) flows for several minutes. This purges air from the heat exchanger.
• 3. Refill tank (storage type): For tank models, open the cold inlet and a hot faucet until water runs steadily with no air. Only then restore power.
• 4. Inspect for leaks: Check around the drain valve, T&P valve, and fittings for leaks that could have drained the tank. Repair any leaks before restarting.
• 5. Reset and test: After confirming the system is full and leak-free, restore power and gas. If E10 returns, internal damage may have occurred and components such as elements or sensors may need replacement.

Note: Electric elements that have been dry-fired are often permanently damaged and should be replaced.