User Guide

ManualsBrandsWeil-McLain ManualsBoiler PartsNG to LP Conversion Kit for AquaBalance 120 MBH Model Boilers

Part number 550-100-325/0718

AquaBalance

SERIES 2 WALL MOUNT GAS-FIRED WATER BOILER — Boiler Manual

Figure 64 Outdoor sensor optional for Combi boiler.

21 Field wiring (continued)

Outdoor temperature sensor Central Heating Boilers

(optional for Combi Boilers)

• Outdoor sensor uses the back connection block,

see Figure 62,

Item 138, (right side of block … terminals 5 and 6).

• Recommended wire size 22 AWG (2-conductor shielded thermo-

stat wire 22 gauge).

• Mount on north exterior wall,

shielded from direct sunlight or

ﬂow of heat or cooling from other sources, approximately 10 feet

above ground level.

• Do NOT run sensor wires with other electrical wires.

The Outdoor sensor must be installed unless speciﬁcal-

ly exempted in the Energy Act statement on page 131.

Figure 65 Indirect tank aquastat connections

Wiring the Indirect Tank Aquastat

Wiring the indirect tank aquastat to the Heating Only Boiler, will ﬁre the

boiler to provide heated boiler water to the indirect tanks heating coil.

• Field supplied; zone panel, with priority zone, indirect circulator,

zone valve for indirect tank.

• Connect indirect aquastat N/O contact wires to boiler connections

#7 and #8, see Figure 65 below.

• Boiler must be in the “comfort mode” (not “eco” mode) push eco/

comfort button to exit “eco” mode, display will Not show “eco”

on display when in correct mode, when using an Indirect Water

Heater Tank.

Wiring the Circulators (Heating Only Boiler)

The control of the Heating Only model of the boiler is ca-

pable of managing two (2) separate circulators, one for the

Heating circuit and one for the Domestic Hot water circuit.

The connections are located on the rear part of the con-

trol case. In order to access the connector you will have to

unscrew the screw located on the lower right corner of the

control to enable you to rotate the control and access the

connectors. See Figure 66 and Figure 67.

Figure 66 Circulator connectors (Heating Only

boilers)

Figure 67 Circulator connectors detail

In Figure 67, terminals 9, 10 and 11 (Item 32) are for con-

necting the Heating circuit circulator.

Terminals 11, 12, and 13 (Item 130) are for connecting the

Domestic Hot water circuit circulator.

The common terminal 11 is ground.

Only one circulator may be wired to each con-

nection point.

Indirect tank aquastat

(N/O) wire connection

points, pins 7 and 8