Abstract: The present invention provides a pressure control isolation tank for a closed loop heating system. A diaphragm within the tank separates heating system fluid from non-system fluid. The heating system fluid is provided under constant pressure, typically 12 PSI. Usually the non-system fluid is service water or clean water flowing through a pressure reducing valve. As the heating system loses system fluid through tiny leaks, and also loses air through vents, the non-system fluid causes the diaphragm to displace the volume lost by the leaked heating system fluid and leaked air. Thus, the heating system fluid is maintained at a constant pressure.

Abstract: There is provided a nozzle assembly setting gauge that is secured to the nozzle assembly. The nozzle assembly setting gauge further includes a setting post that contacts the combustion head when the nozzle assembly is in the proper reset position. As an added feature the nozzle assembly setting gauge also includes an electrode adjuster that allows a technician to properly gap and position the electrode pair without reference to any manuals or the requirements of any special tools. The electrode adjuster can also be independent of the nozzle assembly setting gauge.