Weil-McLain 550-110-260/0107 manual 3c Water piping multiple zones, Systems or converted gravity

GOLD CGs Gas-Fired Water Boiler — Boiler Manual

3c Water piping — multiple zones

Piping multiple zones	Piping for radiant heating
Follow instructions on pages 14 and 15 to install near-	systems or converted gravity
boiler or single-zone piping. (Also refer to Piping for	systems
radiant heating systems or converted gravity sys-
tems, below, if applicable.)	Converted gravity (or steam) systems
See Figure 6 or Figure 7, page 17, to complete instal-
	Whenever possible, use the primary/secondary piping
lation.
	shown in Figures 8 or 9 on page 19. This piping design
Zoning with circulators (Figure 6)	allows changing boiler flow rate without affecting pri-
(return temp over 130°F)	mary circuit flow rate.
	If Figures 8 or 9 cannot be used, use the boiler-bypass
1. Size each circulator to individual circuit require-
	piping shown in Figure 10 or Figure 11 on page 21. You
ments.
	can also use the piping shown in Figure 12 on page 23
2. Do not install circulator on boiler (except for pri-
	(system-bypass), if the reduced flow rate in the heating
mary/secondary piping).
	system will not cause heat distribution problems.
3. Install isolation (balancing) valves to adjust flow to
	Failure to prevent low return water
distribute heat to all zones.
	temperature to the boiler could
4. Install and wire a separate relay for each zone cir-
	cause corrosion of the boiler sec-
culator.
	tions or burners, resulting in severe
	personal injury, death or substantial
Zoning with zone valves (Figure 7)	property damage.
(return temp over 130°F)	Radiant heating systems
1. Install isolation (balancing) valves to adjust flow to	Preferably, use primary/secondary piping, as shown
distribute heat to all zones.	in Figures 8 or 9 on page 19. Alternatively, use the
2. Provide a separate 24-volt transformer to power the	method of either Figure 10 or Figure 11 on page 21.
zone valves. Size the transformer to handle the total	Do not use the piping of Figure 12 (system-bypass),
rated load of all connected zone valves.	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.

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Part number 550-110-260/0107