Rheem Rheem RTEX-13 13kW Point-of-Use Electric Tankless Water Heater ELEMENT LED OFF Error Fix: Elements Not Firing — No Demand or No Power

Error code ELEMENT LED OFF on the Rheem Rheem RTEX-13 13kW Point-of-Use Electric Tankless Water Heater means: Elements Not Firing — No Demand or No Power. All element indicator LEDs are off. This is normal when no hot water is being drawn (standby mode) or when the outlet water has reached the set temperature. If LEDs remain off despite actively running a hot water tap, the unit may not have power: check the circuit breakers (the RTEX-13 requires one dedicated 60-amp double-pole breaker on 6-gauge wire), verify 240VAC at the unit terminal block, and check the flow sensor trigger — a minimum flow rate (approximately 0.4 GPM) is required to activate heating.

The most successful fix is "Test Power Supply and Flow Sensor with Multimeter" (medium difficulty, ~45 minutes). Estimated DIY cost: $10-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated info severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test Power Supply and Flow Sensor with Multimeter") is rated medium difficulty and takes about 45 minutes. Tools needed: T20 Torx screwdriver, Multimeter.

DIY cost: $10-$20. Professional repair typically costs $150-$250. Many homeowners save money by trying the top-ranked community fix first.

The Rheem Rheem RTEX-13 13kW Point-of-Use Electric Tankless Water Heater has 4 other known error codes, including: DISPLAY DASHES (Temperature Sensor Error), ELEMENT LED ON (Heating Elements Active — Normal), LOW TEMP OUTPUT (Insufficient Temperature Rise — Unit Undersized), NO DISPLAY (No Power to Unit — Display Dark).