Weil McLain 512-050-235 Fuse

The Weil McLain 512-050-235 is a critical rollout thermal fuse element designed for high-limit safety monitoring in gas-fired atmospheric boilers and AHE Series 2 and 3 blowers. This thermal cutoff is factory-calibrated to trip at a 121°C (250°F) temperature rating, providing a non-resettable safety break if combustion temperatures breach the firebox boundary. As an essential boiler safety device, it functions by interrupting the electrical circuit to the gas valve, effectively shutting down the burner to prevent damage to the cabinet, wiring harness, and control components. This part is a direct replacement for S1-025-21166-001 and is commonly used in CG, EG, and HE boiler platforms to mitigate risks associated with flame rollout caused by heat exchanger blockages or venting issues. For professional technicians, maintaining the integrity of the thermal safety circuit is paramount; if this fuse has opened, a thorough inspection of the flue passages and burner alignment is required before replacing the element to ensure safe system operation.

• OEM Precision: Genuine Weil McLain replacement part ensures exact calibration and fitment for AHE blower and boiler safety assemblies.
• Critical Protection: Reliable combustion safety switch prevents hazardous overheating and potential fire conditions by severing power at 250 degrees Fahrenheit.
• Cross-Compatibility: Fully interchangeable with S1-025-21166-001, offering versatility for fleet service and multifaceted inventory management.
• Durable Construction: Engineered to withstand the high-ambient environments of professional HVACR combustion chambers.

Is the 512-050-235 rollout fuse resettable?
No, this is a one-time thermal fuse element. Once it reaches its 121°C threshold and the internal element melts, the entire unit must be replaced to restore the safety circuit.

What causes a thermal rollout fuse to trip on a Weil McLain boiler?
Tripping is typically caused by flame rollout, which occurs when heat exchanger passages are soot-clogged, or if there is a severe lack of combustion air or flue blockage forcing heat toward the control area.

Can I use a higher temperature fuse if the 250°F model keeps blowing?
Substitution is not recommended. This thermal cutoff is spec'd by the manufacturer based on the temperature limits of surrounding components. If it trips repeatedly, the root cause in the combustion or venting system must be addressed.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.