Robertshaw 1951-536 Thermopile

The Robertshaw 1951-536 Thermopile is a heavy-duty, 36-inch threaded thermopile designed for use in self-powered gas control systems commonly found in commercial deep fryers, gas fireplaces, and floor furnaces. Engineered to generate a consistent 750 millivolt (mV) output, this coaxial-style generator utilizes two dissimilar metals to convert thermal energy from a steady pilot flame into electrical current, sufficient to energize a millivolt gas valve without external power. The threaded nut mounting ensures a secure, leak-free seat within the pilot burner bracket, maintaining alignment in high-heat environments. As a direct replacement for the G251R36S, this Robertshaw thermopile features an Outer Inconel sheath for long-term resistance to oxidation and high-temperature scaling. For technicians performing HVAC pilot assembly repair, verifying the thermopile millivolt output under load is critical to ensuring reliable main burner ignition and preventing nuisance dropouts during heavy duty cycles.

Key Benefits

• High Output Performance: Delivers a reliable 750mV signal to ensure proper millivolt gas valve actuation.
• Direct Compatibility: Engineered as a drop-in replacement for the Robertshaw G251R36S and similar coaxial thermopile configurations.
• Robust Construction: The 36-inch lead length provides ample reach for large equipment while the threaded connection ensures vibration resistance.
• Self-Powered Reliability: Enables operation of heating appliances during power outages by generating its own control voltage.

Common Questions

How do I test if my Robertshaw 1951-536 is failing?
Using a multimeter set to DC millivolts, measure the output while the pilot is hitting the tip. An open-circuit reading should be between 650mV and 850mV; a reading below 325mV under load typically indicates the need for replacement.

What causes a thermopile to stop generating voltage?
Common failure points include heavy carbon soot accumulation on the sheath, an improper pilot flame pattern that doesn't engulf the top 1/2-inch of the element, or internal degradation of the junction due to excessive heat.

Is this thermopile compatible with propane or natural gas?
Yes, the Robertshaw 1951-536 is atmosphere-neutral and functions correctly with both LP and Natural Gas pilot assemblies, provided the pilot flame is adjusted to the correct intensity.

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.