Watts 0590712 Air Vent or if you get a

or if you get a 4-flash error code on your control board

Under normal room temperature conditions

this is the standalone Honeywell logo protective cover accessory only

Hydraulic Efficiency: Maintains the critical seal between the pump head and the volute

This HVAC pilot assembly component is critical for achieving optimal AFUE ratings in high-input residential and light commercial systems

Watts 0590712 Air Vent or if you get aThe Watts 0590712, also designated as the HAV 1 8, is a heavy duty automatic air vent designed for high performance air management in hydronic heating systems and low pressure steam applications. Built with a robust 2 piece chromed brass body, this 1 8" NPT straight pattern vent maintains system efficiency by continuously purging trapped air from radiators, baseboards, and convectors. The core of the unit utilizes advanced hygroscopic technology,