Weil-McLain 550-110-710/0107 manual 4c Water piping — multiple zones continued

GOLD CGi Gas-Fired Water Boiler — Boiler Manual

4c Water piping — multiple zones (continued)

Figure 18 Zoning with circulators	Figure 19 Zoning with zone valves
— return water 130°F or higher.	— return water 130°F or higher.

1	Boiler isolation (balancing) valves	10	Automatic air vent (with diaphragm-type expansion tank), or con-
			nect to tank fitting (closed-type expansion tank). DO NOT use an
2	Flow/check valve		automatic air vent when using closed-type expansion tank. It would
			allow air to leave the system, causing waterlogging of the expansion
3	System or zone circulator		tank.
		11	Fill valve
5	Zone valve	12	Diaphragm-type or bladder-type expansion tank, if used (For
			closed-type expansion tank, pipe from top of air separator to tank
6	Drain valve		fitting as in Figure 17.)
9		13	Air separator and automatic vent, if used (Note that the fill valve
	Relief valve		must always be connected to the expansion tank, regardless of loca-

For systems with possible low return-water temperature (such as converted gravity systems, radiant heating systems and heat pump systems), refer to the special piping suggestions of Figures 20 – 24, as applies. Failure to prevent sustained low return water temperature to the boiler could cause corrosion of the boiler sections, resulting in severe personal injury, death or substantial property damage.

Part Number 550-110-710/0107 23