Johnson Controls A28AA-29 Temperature Control R-410A Replacing the full set of

Replacing the full set of 9 ensures uniform pressure across the header plate

this manual reset thermal switch ensures the combustion chamber remains within safe operating parameters by interrupting the millivolt signal to the gas control valve if internal temperatures exceed 240°F

and 135 PSI for light oil

the integrated overflow switch includes 1/4-inch quick-connect terminals

this unit utilizes a mid-point ground configuration to ensure balanced electrical stress across the secondary windings

Johnson Controls A28AA-29 Temperature Control R-410A Replacing the full set ofThe Johnson Controls A28AA 29 is a heavy duty two stage temperature control designed for precise cycling of multiple HVACR components. Featuring 2 SPDT switch action, this mechanical thermostat allows for sequenced control of heating, cooling, or ventilation equipment across a broad 30 to 100 degree setpoint range. For technicians replacing legacy components, the A28AA 29 serves as the direct Johnson Controls A28AA 81 replacement, maintaining exact