Weil-McLain Electric Water Heater Install system water piping space heating continued

PLUS Line Instruction Manual Supplement

PLUS & PLUS WATER HEATERS WITH GAS-FIRED WATER BOILERS

1 Install system water piping (space heating) (continued)

Zoning with zone valves				Figure 2 Zone valve zoning plus optional
1.	Connect boiler to system as shown in Figure 2			water heater piping
	when zone valve zoning. The primary/secondary
	piping shown ensures the boiler loop will have
	sufficient flow. It also avoids applying the high head
	of the boiler circulator to the zone valves.
2.	When using a closed-type expansion tank, connect
	the expansion tank and make-up water piping as
	shown in Figure 1, page 3.
3.	Connect water heater (domestic hot water) piping
	to indirect storage water heater as shown.
		The	PhDControl Module turns off

space heating during water heater 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 water heater heating.

4.Controlling the system circulator

a.To cycle the system circulator from the Ultra PhD control module, add a circulator relay wired to the boiler circulator terminals as shown on page 8.

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 Ultra-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 2

1Ultra boiler

2Indirect water heater (water heater), if used

3Boiler relief valve (see boiler manual for piping details)

4Relief valve discharge piping (see boiler manual for details)

5Water heater circulator (see page 7 for suggested sizing)

6Isolation valves

7System circulator

8Diaphragm (or bladder) type expansion tank (see page 3 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

13Zone valves, typical

20Make-up water supply

21Primary/secondary connection

4 Part number IWHA016A/1103