Hydrotherm 62-3668 Pilot Assembly

The Hydrotherm 62-3668 Pilot Assembly is a high-performance intermittent pilot ignition component engineered for specialized Hydrotherm boiler models including the HC, R, VS, and VGA series. This natural gas pilot assembly is functionally identical to the Honeywell Q3451B1103, providing a direct-replacement solution for contractors maintaining legacy hydronic heating systems. Designed as a low-output target-type pilot burner, it incorporates a spark igniter and flame sensor to ensure precise proving pilot operation. With a sustained spark gap rated between .080 in. and .140 in., this assembly delivers consistent flame rectification and light-off reliability, even in demanding commercial and residential boiler environments. Utilizing Kanthal electrode materials for high-temperature resistance and a 1/4 inch compression fitting for gas connections, the 62-3668 minimizes nuisance lockouts by providing a stable Bunsen-type flame that effectively rectifies the flame signal back to the ignition module.

• OEM Compatibility: Cross-references directly with Honeywell Q3451B1103 and replaces Hydrotherm 22-623668 for seamless field installation.
• Optimized Ignition: Features a high-integrity spark electrode and sensor that prevents flame lifting and reduces ignition lag.
• Durable Construction: Built with Kanthal flame rod materials and ceramic insulators rated for 1775?F to withstand continuous thermal cycling.
• Versatile Application: Validated for use in Hydrotherm HC-145D, HC-100D, EW-100, and VGA-300B boilers, among many other Hydrotherm heating systems.
• Safety Focused: Provides immediate flame sensing, ensuring the gas valve only remains open when a verified pilot flame is present.

What boiler models is this pilot assembly compatible with?
The Hydrotherm 62-3668 is commonly found in Hydrotherm HC series (HC-65D through HC-165D), VS series, and VGA series boilers. It is also a match for certain EW models. Always verify the Honeywell Q3451B1103 part number on your existing assembly before replacement.

Can I use this for Propane (LP) gas systems?
No, this specific model is a natural gas pilot assembly. Using a natural gas orifice in an LP system will result in improper combustion and unsafe operating conditions. For LP applications, the orifice must be converted by a licensed technician.

Why is my new pilot sparking but not lighting?
This is often caused by clogged pilot orifices or incorrect pilot gas pressure. Check for debris in the target burner and ensure the 1/4 inch gas line is free of obstructions. Ensure the spark gap is within the manufacturer's .080 in. to .140 in. specification for a reliable blue spark.

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.