Ariston water heater produces very little or no hot water, but the tank feels hot or heats briefly then runs cold.

Safety first: Turn off power and close the cold water supply before opening any plumbing connections.

• Check plumbing connections: Verify that cold water is connected to the inlet marked with blue and hot to the outlet marked with red on the Ariston heater.
• Inspect for cross-connection: Temporarily close the cold supply to the heater and open a hot tap. If water still flows strongly, there may be a cross-connection in the plumbing that must be corrected.
• Check dip tube: Remove the cold inlet fitting and gently pull out the plastic dip tube. If it is broken, shortened, or missing, replace it with an Ariston-compatible dip tube of correct length.
• Flush tank: While drained, flush sediment from the tank to improve stratification and capacity.