Bradford White D-W-2-75T6BN Ultra Low NOx 4-FLASH Error Fix: High Temperature / ECO Trip

Error code 4-FLASH on the Bradford White D-W-2-75T6BN Ultra Low NOx means: High Temperature / ECO Trip. The ICON System LED blinks four times, indicating the water temperature has exceeded the high-limit safety threshold (approximately 180°F / 82°C). The Energy Cut Off (ECO) has tripped and shut down the gas valve to prevent scalding or tank damage. This is a serious safety condition. Allow the water to cool, then press the red reset button on the gas control valve to restore operation. If the ECO trips repeatedly, the gas valve thermostat may be malfunctioning, the temperature setting may be too high, or there may be a stacking condition from excessive hot water draws. A faulty gas valve that fails to shut off the burner at the set temperature must be replaced immediately.

The most successful fix is "Replace Gas Control Valve and Inspect Tank for Damage" (hard difficulty, ~90 minutes). Estimated DIY cost: $20-$40. 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 Gas Control Valve and Inspect Tank for Damage") is rated hard difficulty and takes about 90 minutes. Tools needed: Adjustable wrench, Pipe joint compound, Multimeter, Phillips screwdriver, Bucket or hose for draining.

DIY cost: $20-$40. Professional repair typically costs $350-$500. Many homeowners save money by trying the top-ranked community fix first.

The Bradford White D-W-2-75T6BN Ultra Low NOx has 8 other known error codes, including: 1-FLASH (Normal Operation — System OK), 2-FLASH (Thermopile Voltage Low), 5-FLASH (Temperature Sensor Failure), 7-FLASH (Gas Control Valve Electronics Failure), 8-FLASH (Power Interruption / Loss of Pilot Signal), and 3 more.

Error code 4-FLASH also appears on 6 other Bradford White models: MI50S6BN 50 Gallon 76,000 BTU Magnum Series Commercial Natural Gas Water Heater, MI50T6FBN 50 Gallon 40,000 BTU Natural Gas Magnum Commercial Water Heater, RG240T6N eF Series, RG250T6N 50 Gallon 40,000 BTU 0.67 EF Defender Safety System Gas Water Heater, RG2PV40T6N 40 Gallon 40,000 BTU Power Vent Gas Water Heater with Defender Safety System, RG2PV50H6N 50 Gallon 40,000 BTU Power Vent Gas Water Heater with Defender Safety System. The fix may vary by model, so check each model's specific page for tailored repair steps.