Tankless water heater shows E1 and will not ignite; no hot water at any fixture.

Safety first: Turn OFF electrical power and close the manual gas shutoff valve before servicing. Do not attempt repairs if you smell gas—evacuate and contact your gas supplier.

• Verify gas supply: Ensure the gas shutoff valve to the Richmond heater is fully open. Check that other gas appliances in the home are working. If none work, contact your gas provider.
• Check air intake and exhaust: Inspect the intake and exhaust vent pipes for obstructions (leaves, nests, snow, debris). Clear any blockage and ensure proper termination per Richmond installation instructions.
• Clean ignition and flame sensor: Remove the front cover. Locate the ignition electrode and flame sensor near the burner. Gently clean the metal tips with fine emery cloth or a Scotch-Brite pad to remove carbon buildup. Do not bend the rods.
• Inspect burner: Look for heavy dust, lint, or rust flakes on the burner surface. Use a soft brush and vacuum to clean. Do not use water or harsh chemicals.
• Reset and test: Restore gas and power, then reset the unit. Open a hot water tap fully and observe if ignition occurs. If E1 returns, a technician should check gas pressure and may need to replace the ignition electrode or flame sensor.