Weil-McLain CGI-4E manual 4c Water piping - multiple zones, Piping multiple zones

GOLD CGi-4E Gas-Fired Water Boiler — Boiler Manual

4c Water piping — multiple zones

Piping multiple zones

Follow instructions on pages 20 and 21 to install near-

boiler or single-zone piping. (Also refer to Piping for radiant heating systems or converted gravity sys-

tems, below, if applicable.)

See Figure 18 or Figure 19 to complete installation.

Zoning with circulators (Figure 18) (return temp over 130°F)

1.Size each circulator to individual circuit require- ments.

2.Do not install circulator on boiler (except for pri- mary/secondary piping).

3.Install isolation (balancing) valves to adjust flow to distribute heat to all zones.

4.Install and wire a separate relay for each zone cir- culator.

Zoning with zone valves (Figure 19) (return temp over 130°F)

1.Install isolation (balancing) valves to adjust flow to distribute heat to all zones.

2.Provide a separate 24-volt transformer to power the zone valves. Size the transformer to handle the total rated load of all connected zone valves.

Piping for radiant heating systems or converted gravity systems

Converted gravity (or steam) systems

Whenever possible, use the primary/secondary piping shown in Figures 20 or 21 on page 25. This piping de- sign allows changing boiler flow rate without affecting primary circuit flow rate.

If Figures 20 or 21 cannot be used, use the boiler-bypass piping shown in Figure 22 or Figure 23 on page 27. You can also use the piping shown in Figure 24 on page 29 (system-bypass), if the reduced flow rate in the heating system will not cause heat distribution problems.

Failure to prevent low return water temperature to the boiler could cause corrosion of the boiler sec- tions or burners, resulting in severe personal injury, death or substantial property damage.

Radiant heating systems

Preferably, use primary/secondary piping, as shown in Figures 20 or 21 on page 25. Alternatively, use the method of either Figure 22 or Figure 23 on page 27. Do not use the piping of Figure 24 (system-bypass), because this method does not control radiant system supply temperature.

If radiant system tubing has no oxygen barrier, a heat exchanger must be used.

Radiant heating system piping should include a means of regulating the boiler return water temperature and the system supply temperature (such as provided by an injection pumping control). Boiler return water temperature will be adequately controlled using the methods shown in this manual provided the system supply temperature is relatively constant.

DO NOT apply the methods in this manual if the system is equipped with an outdoor reset control. Instead, provide controls and piping which can regulate the boiler return water temperature at no less than 130°F regardless of system supply temperature. Contact your Weil-McLain representative for suggested piping and control methods. Failure to prevent cold return water temperature to the boiler could cause corrosion damage to the sections or burners, resulting in possible severe personal injury, death or substantial property dam- age.

22 Part Number 550-110-711/1108