Weil-McLain 230, 80, 310, 105, 155 manual Zoning with circulators

3 GAS-FIRED WATER BOILER — Boiler Manual

Install water piping (continued)

Zoning with circulators				Figure 8	Circulator zoning plus optional
1.	Connect boiler to system as shown in Figure 8 when				DHW piping
	circulator zoning. The boiler circulator cannot be used
	for a zone. It must supply only the boiler loop.
2.	Install a separate circulator for each zone.
3.	When using a closed-type expansion tank, connect
	the expansion tank and make-up water piping as
	shown in Figure 4, page 13.
4.	Connect DHW (domestic hot water) piping to indirect
	storage water heater as shown.
		The	PhDControl Module turns off

space heating during DHW heating. The boiler circulator will turn off, preventing hot water from circulating to the system. The flow/check valve shown on the boiler outlet piping prevents gravity circulation in the boiler loop during DHW heating.

NOTE 1: To ensure adequate flow rate through the boiler, use the following pipe size on all boiler loop piping (connecting boiler to and from the primary/secondary connection, item 21): Ultra-80 or Ultra-105 – 1" or larger.

Ultra-155 or -230 – 1¼" or larger. Ultra-310 – 1½" or larger.

Use at least the minimum piping size above and pipe the boiler using only primary/ secondary piping as shown. Failure to follow these guidelines could result in system problems.

Legend Figure 8

1Ultra boiler

2Indirect water heater (DHW), if used

3Boiler relief valve (see page 12 for piping details)

4Relief valve discharge piping (see page 12 for details)

5DHW circulator (see page 14 for suggested sizing)

6Isolation valves

7System circulator

8Diaphragm (or bladder) type expansion tank (see page 12 for piping of closed-type expansion tank, if used)

9Air separator [with automatic air vent only on systems using diaphragm (or bladder) type expansion tank]

10Flow/check valves (with weighted seats to prevent gravity circulation)

11Purge/drain valves

12Boiler circulator

14Zone circulators, typical

20Make-up water supply

21 Primary/secondary connection

16 Part number 550-101-233/0903