Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater 72 Error Fix: Flame Detection Circuit Failure

Error code 72 on the Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater means: Flame Detection Circuit Failure. The flame rod detection circuit on the PCB has a hardware fault. The flame rod itself may be functioning, but the electronic circuit that processes the flame signal on the main PCB cannot interpret it correctly. This typically requires PCB (main control board) replacement. Before replacing the board, verify: the flame rod wire is properly connected to the PCB terminal, the wire is not shorted to the chassis or housing, and the flame rod itself is not cracked or grounded. If all external checks pass and the code persists, replace the PCB.

The most successful fix is "Replace the Main Control Board (PCB)" (medium difficulty, ~60 minutes). Estimated DIY cost: $150-$200. 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 the Main Control Board (PCB)") is rated medium difficulty and takes about 60 minutes. Tools needed: Phillips screwdriver, Multimeter.

DIY cost: $150-$200. Professional repair typically costs $350-$500. 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: 05 (False Flame Detection), 10 (Abnormal Combustion — Blocked Vent), 11 (Ignition Failure — No Flame Detected), 12 (Flame Failure — Flame Lost During Operation), 14 (Thermal Fuse Activated — Overheat Safety), and 3 more.