Bradford White MI50S6BN 50 Gallon 76,000 BTU Magnum Series Commercial Natural Gas Water Heater MECH-SEDIMENT Error Fix: Sediment Buildup — Rumbling or Popping Noise

Error code MECH-SEDIMENT on the Bradford White MI50S6BN 50 Gallon 76,000 BTU Magnum Series Commercial Natural Gas Water Heater means: Sediment Buildup — Rumbling or Popping Noise. The water heater makes rumbling, popping, or banging sounds during heating, especially when the burner first fires. This is caused by sediment (mineral scale, calcium, sand) that has accumulated at the bottom of the tank. As the burner heats the tank bottom, water trapped under the sediment layer turns to steam, creating popping sounds as steam bubbles escape through the sediment. Flush the tank by connecting a garden hose to the drain valve at the bottom and draining several gallons. For heavy sediment, a full drain-and-refill may be needed. Prevent buildup by flushing the tank annually. Heavy sediment reduces heating efficiency and accelerates tank corrosion.

The most successful fix is "Perform Full Drain and Replace Anode Rod if Needed" (medium difficulty, ~90 minutes). Estimated DIY cost: $15-$30. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Perform Full Drain and Replace Anode Rod if Needed") is rated medium difficulty and takes about 90 minutes. Tools needed: Garden hose, 1-1/16 inch socket wrench, Adjustable wrench, Gloves, Safety glasses.

DIY cost: $15-$30. Professional repair typically costs $180-$250. Many homeowners save money by trying the top-ranked community fix first.

The Bradford White MI50S6BN 50 Gallon 76,000 BTU Magnum Series Commercial Natural Gas Water Heater has 8 other known error codes, including: 1-FLASH (Normal Operation — System OK), 2-FLASH (Thermopile Voltage Low), 4-FLASH (High Temperature / ECO Trip), 5-FLASH (Temperature Sensor Failure), 7-FLASH (Gas Control Valve Electronics Failure), and 3 more.

Error code MECH-SEDIMENT also appears on 8 other Bradford White models: D-W-2-75T6BN Ultra Low NOx, MI50T6FBN 50 Gallon 40,000 BTU Natural Gas Magnum Commercial Water Heater, RE340S6 40 Gallon 4500W Short Electric Water Heater with Glass Lining, RE350T6 50 Gallon 4500W 6-Year Warranty Upright Electric Water Heater, RG240T6N eF Series, RG250T6N 50 Gallon 40,000 BTU 0.67 EF Defender Safety System Gas Water Heater, and 2 more. The fix may vary by model, so check each model's specific page for tailored repair steps.