Weil-McLain GOLD DV WATER BOILER IIIf Water piping — radiator system, Radiator system piping

GOLD GV Water boiler series 3 — manual

IIIf Water piping — radiator system

Figure 12a Radiator system — zone-valve zoning

Zone 2

Zone 1

12"

max

Cold water

fill

GV Boiler

85013b

Figure 12b Radiator system — circulator zoning

Zone 2

Zone 1

12"

max

Cold

water

fill

GV Boiler

Radiator system piping

Apply Figure 12a (zone-valve zoning) or 12b (circulator zoning) to systems using standing cast iron radiators. This applies to gravity water systems and converted steam systems using columnar, tubular or recessed cast iron radiators.

The suggested piping for zone-valve zoning radiator systems differs from baseboard systems because of the high water content of cast iron radiators. The GV internal circulators automatically regulate supply and internal bypass flow based on the temperature of the water returning to the boiler. At the start of many heating cycles in a radiator system, the water in the radiators is cool. So the boiler would slow down system flow rate while sending out relatively hot water. This could cause heat distribution problems. Install a separate system circulator as shown in Figure 12a when zoning with zone valves. The separate circulator assures a relatively constant temperature drop through the system.

The boiler internal circulators must be left in the boiler. They cannot be removed for use a a zoning circulator. Provide a circulator for each zone when circulator zoning, and pipe the system as in Figure 12b.

Legend

1Boiler isolation valves

2Automatic air vent (with diaphragm-type expansion tank), or connect to tank fitting (closed-type expansion tank).

3Diaphragm- or bladder-type expansion tank, if used. (For closed-type expansion tank, pipe from top of air separator to tank fitting as in Figure 10.)

4Zone valve

5System or zone circulator

6Flow/check valve

7Hose bibb purge valve

85017	8	Boiler pressure/temperature gauge
32		Part number 550-141-850/0699