Tankless water heater shows E7; unit may not ignite or may shut down intermittently.

Safety first: Turn OFF power and close the gas shutoff valve. Gas work can be dangerous; if you smell gas, evacuate and contact your gas supplier immediately.

• Step 1 – Verify gas supply and type: Confirm the heater is set up for the correct gas type (natural gas or LP) and that supply pressure meets Ruud specifications. This usually requires a manometer and should be done by a professional.
• Step 2 – Inspect wiring: Remove the front cover and locate the gas valve assembly. Check that all electrical connectors are fully seated and free of corrosion or damage.
• Step 3 – Reset unit: Restore power and gas, then attempt operation. If E7 reappears, shut everything OFF again.
• Step 4 – Replace gas valve (advanced): If wiring is intact and gas supply is correct, the gas valve may be defective. Turn OFF gas and power, disconnect the gas piping at the union, remove mounting screws, disconnect wiring, and install a new OEM Ruud gas valve assembly. Use approved pipe sealant and leak-test all joints with a soap solution before operation.

Because gas valve replacement and pressure adjustment are safety-critical, most homeowners should contact a qualified technician for this repair.