Weil McLain 510-312-166 Relay

The Weil McLain 510-312-166 Relay is an indispensable OEM boiler replacement part specifically engineered for residential gas systems. This 120V to 24V step-down transformer and relay receptacle combination delivers a stable 40VA power rating, providing the necessary current for spark ignition controls and external thermostat circuits. Designed for high-performance switching, the DPDT relay configuration (Double Pole Double Throw) ensures reliable logic control without the relay itself included, allowing for customized field installation of the compatible 510-350-223 plug-in relay. This HVAC control transformer is a direct fit for Weil-McLain EG, EGH, CG, and PFG series boilers, maintaining factory-spec voltage regulation to protect sensitive downstream components from fluctuations. For technicians servicing legacy or modern hydronic systems, this unit replaces part number 10C053 and effectively integrates with White-Rodgers S4A-85 and Honeywell R8285K equivalent setups. Its compact 4-1/4" by 4-3/8" footprint facilitates rapid installation in tight boiler cabinets, ensuring minimal downtime during critical calls.

• OEM Compatibility: Exact replacement for Weil-McLain CG, EG, and PFG series boilers to ensure electrical synchronization.
• Dual-Voltage Efficiency: Pre-wired for 120V primary input and 24V secondary output, meeting standard low-voltage HVAC control requirements.
• Robust Construction: Heavy-duty 40VA transformer handles peak loads for spark ignition and logic boards without saturation.
• Standardized Housing: Features a durable bale wire retention system for secure mounting in high-vibration environments.

Common Questions

Does this unit include the plug-in relay?
No, this is a "less relay" model. It serves as the transformer and relay receptacle. If a switching relay is required for your specific sequence of operation, use a compatible 510-350-223 plug-in relay.

Which boiler models are compatible with the 510-312-166?
This boiler combination transformer is engineered for a wide range of Weil-McLain residential gas units, including the CGx, HE, VHE, and all EG/EGH series modules.

Can I use this to replace a White-Rodgers or Honeywell equivalent?
Yes, this 40VA DPDT relay center is the manufacturer-specified replacement for White-Rodgers S4A-85 and Honeywell R8285K-1004 configurations within Weil-McLain systems.

This item is not eligible for free shipping.

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.