Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater 05 Error Fix: False Flame Detection

Error code 05 on the Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater means: False Flame Detection. The flame rod is detecting a flame signal when the burner should be completely off. This is a safety condition that shuts down the unit. Possible causes: residual flame lingering in the combustion chamber after burner shutdown, a faulty flame rod providing a false signal, or a PCB (printed circuit board) malfunction interpreting noise as a flame signal. Turn off the unit and the gas supply immediately. Allow the unit to cool completely before restarting. If Code 05 reappears on restart, the PCB or flame rod assembly needs replacement by a qualified technician.

The most successful fix is "Replace Flame Rod and Inspect PCB Connections" (hard difficulty, ~90 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

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

Yes — the top-ranked community fix ("Replace Flame Rod and Inspect PCB Connections") is rated hard difficulty and takes about 90 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Needle-nose pliers.

DIY cost: $15-$25. Professional repair typically costs $250-$400. Many homeowners save money by trying the top-ranked community fix first.

The Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater has 8 other known error codes, including: 10 (Abnormal Combustion — Blocked Vent), 11 (Ignition Failure — No Flame Detected), 12 (Flame Failure — Flame Lost During Operation), 14 (Thermal Fuse Activated — Overheat Safety), 16 (Overheating — Outgoing Water Too Hot), and 3 more.