McDonnell & Miller SA159-17 Y AssemblyMcDonnell & Miller SA159 17 is a Black 'y' Assembly designed for boiler control applications. This SA159 17 part (model 349400) is a reliable replacement component for systems using McDonnell & Miller controls, ensuring consistent operation and easy integration. Specifically compatible with 42a, 47, and 64a configurations, the Y assembly supports critical control flow in safe boiler management. Ideal for HVAC and industrial boiler setups, it serves as

Used On: HD100/HDB100/HDS100/HDC100 gas-fired unit heaters

235 PSI rating

it helps maintain efficiency and reduces service calls

and straightforward maintenance scheduling

electric modulation for commercial HVAC dampers

enabling reliable performance in demanding environments

Ideal for maintenance teams

GUIV090CX50

Voltage rating is 24 V (AC/DC) with 50/60 Hz input

ensuring seamless field replacement

corrosion-resistant materials designed for long-term reliability in hydronic systems

The unit includes a Proof of Closure Switch and Damper Shaft for verifiable shutoff—note that an Auxiliary Switch is not included