Bradford White RE340S6 40 Gallon 4500W Short Electric Water Heater with Glass Lining MECH-TPR-VALVE Error Fix: T&P Relief Valve Leaking or Dripping

Error code MECH-TPR-VALVE on the Bradford White RE340S6 40 Gallon 4500W Short Electric Water Heater with Glass Lining means: T&P Relief Valve Leaking or Dripping. The temperature and pressure relief valve (T&P or TPR valve) on the side of the tank is dripping or releasing water. This valve is a critical safety device that opens when tank pressure exceeds 150 PSI or temperature exceeds 210°F. Occasional dripping can be caused by thermal expansion — when water is heated it expands, and if the home plumbing has a check valve or pressure-reducing valve, the expanding water has nowhere to go. Install a thermal expansion tank on the cold water supply if one is not present. If the T&P valve releases a large volume of water, the thermostat or ECO may have failed, causing overheating. Never cap or plug a T&P valve — replace it if it drips continuously with normal temperature and pressure.

The most successful fix is "Replace the Temperature & Pressure Relief Valve" (medium difficulty, ~45 minutes). Estimated DIY cost: $20-$40. HomeMD has 2 community-ranked fixes for this error.

This error is rated high severity. You should address it promptly — continued use could cause damage or safety concerns.

Yes — the top-ranked community fix ("Replace the Temperature & Pressure Relief Valve") is rated medium difficulty and takes about 45 minutes. Tools needed: Pipe wrench, Adjustable wrench, Teflon tape.

DIY cost: $20-$40. Professional repair typically costs $150-$250. Many homeowners save money by trying the top-ranked community fix first.

The Bradford White RE340S6 40 Gallon 4500W Short Electric Water Heater with Glass Lining has 8 other known error codes, including: MECH-ANODE (Anode Rod Depleted — Rotten Egg Smell or Corrosion), MECH-ECO-TRIP (ECO (Energy Cut Off) Tripped — Red Reset Button), MECH-ELEMENT-LOWER (Lower Heating Element Failed), MECH-ELEMENT-UPPER (Upper Heating Element Failed), MECH-INSUFFICIENT-HOT (Not Enough Hot Water — Runs Out Quickly), and 3 more.

Error code MECH-TPR-VALVE also appears on 8 other Bradford White models: D-W-2-75T6BN Ultra Low NOx, 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, 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.