Weil-McLain Eco Tec 2 Series Advanced Manual page 38

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ECO Tec series 2 gas-fired water boiler – advanced manual
Field wiring
(see wiring diagram, Figure 18, page 44) (continued)
Combi models use Input/Output pairs 1 and 4 for 3-way valve operation and cannot be used for any
other purpose. Use Input 2 for Indirect DHW (if needed) and Input 3 for Space Heating applications.
To cause AUTOMATIC reset: Connector J20 #3 & #4
The control will reset automatically after circuit is interrupted.
1. Remove factory-installed jumper and connect isolated contacts of external
limits across J20 pins 3 and 4 to cause the control to shut down the boiler on
limit opening, then automatically restart 150 seconds after the limit closes.
2. See drawing at right and wiring diagram (Figure 18, page 44).
G. Low water cutoff (LWCO) – Required (Installer Supplied)
Connector J21
1. Install a low water cut-off (required - Install supplied)
2. Wiring Weil-McLain LWCO Kit:
a. When possible, use the Weil-McLain Low water cut-off kit listed in the back
of this manual. It includes a probe-type low water cut-off and provides a
simple harness connection for the wiring.
b. Connect as shown at bottom center in the control wiring diagram
(Figure 18, page 44).
3. Wiring another LWCO — must have isolated contact:
a. Other low water cut-offs can be used with the ECO Tec only if the device
uses an isolated contact for the LWCO function.
b. Connect as shown at bottom right.
H. Alarm contacts –
Connector J18 #4 & #5
1. The control's alarm dry contact (J18, terminals 4 and 5) closes when the
boiler enters manual lockout only.
2. Connect these terminals for remote alarm notification.
3. Contact electrical ratings: 24VAC or less; 0.5 amp or less.
I. Additional heat demand contacts –
Terminal Block J18 #6 & #7
1. The circuit board can be set to activate another heat source using its additional
heat demand dry contacts through terminal block J18 pins 6 & 7.
2. Connect these terminals to call for heat from the other heat source.
3. Contact electrical ratings: 24VAC or less; 0.5 amp or less.
4. Set the control to activate the heat demand contacts as needed.
5. For Additional Heat Demand, refer to setup in Control section for more
information.
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OPTIONAL
OPTIONAL
See Figure 18, page 44 for details.
See Figure 18, page 44 for details.
See Figure 18, page 44 for details.
See Figure 18, page 44 for details.
Part number 550-100-272/1021