Weil-McLain CGI-4E manual 4c Water piping — multiple zones continued

GOLD CGi-4E 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.

1Boiler isolation (balancing) valves

2Flow/check valve

3System or zone circulator

5Zone valve

6Drain valve

9Relief valve

10Automatic air vent (with diaphragm-type expansion tank), or con- nect to tank fitting (closed-type expansion tank). DO NOT use an automatic air vent when using closed-type expansion tank. It would allow air to leave the system, causing waterlogging of the expansion tank.

11Fill valve

12Diaphragm-type or bladder-type expansion tank, if used (For closed-type expansion tank, pipe from top of air separator to tank fitting as in Figure 17.)

13Air separator and automatic vent, if used (Note that the fill valve must always be connected to the expansion tank, regardless of loca- tion of expansion tank circulator or air separator.

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 550-110-711/1108 23