Weil-McLain CGA25SPDN manual 3c Water piping - multiple zones, Piping multiple zones

GOLD CGa Gas-Fired Water Boiler — Boiler Manual

3c Water piping — multiple zones

Piping multiple zones

Follow instructions on pages 16 and 17 to install near- boiler or single-zone piping. (Also refer to 0IPING FOR

RADIANTIHEATINGTSYSTEMSTOR CONVERTEDEGRAVITY SYS

TEMS below, if applicable.)

See &IGURE  or &IGURE PAGE  TO COMPLETE IN- stallation.

Zoning with circulators (Figure 11) (return temp over 130°F)

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

 $O NOTOINSTALLTCIRCULATOR ON BOILER EXCEPTCFOROPRI- 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 12) (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 &IGURESU or  on page 21. This piping de- sign allows changing boiler flow rate without affecting primary circuit flow rate.

If &IGURESU or  cannot be used, use the boiler-bypass piping shown in &IGURE  or &IGURE  ON PAGE 9OU can also use the piping shown in &IGURE  on page 25 (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 &IGURESU or  on page 21. Alternatively, use the method of either &IGURE  or &IGURE  on page 23. $O NOTOUSESTHEHPIPING OF &IGURE  (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 R"OILER RETURN WATERTTEMPERATURERWILL BE ADEQUATELY CONTROLLED USINGITHEHMETHODSH shown in this manual provided the system supply temperature is relatively constant.

$/ ./4 apply the methods in this manual if the system is equipped with an OUTDOORDRESETS CONTROL. Instead, provide controls and piping which can regulate the boiler return water

TEMPERATURERAT NO LESS THAN —&REGARDLESS OF SYSTEM SUPPLY TEMPERATUREA#ONTACTTYOUR 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.

18 Part Number 550-101-009/0107