Install Instructions

65
13.0 External Modulating Control
SECTION XIII - EXTERNAL
MODULATING CONTROL
The boiler can directly accept an analog 0-10
VDC signal to control the firing rate from an
external modulating boiler controller.
13.1 Wiring the Modulating Controller
Run two 18 gauge wires from the external
modulating boiler controller’s 0-10 VDC boil-
er output to the modulation signal terminals on
the low voltage terminal strip located on the
boiler control module inside the enclosure (see
Fig. 20 on page 31 and Fig. 22 on page 33).
This signal will both enable and modulate the
boiler. No wiring is required at the thermostat
terminals.
Ensure that the polarity of the connec-
tions from the external modulating boil-
er controller to the boiler are correct.
Reversed polarity will lead to no
response from the boiler.
13.2 ACVMax Adjustment
The ACVMax control must be programmed to
accept the 0-10 VDC signal from the external
modulating boiler control.
1. Use the Heating EZ Setup function to set
the CH Demand to 0-10V Modulation
Signal. Reference page 46 for the Heating
EZ Setup function.
13.3 Programming of External
Modulating Control
The external modulating control must be pro-
grammed to send 2 VDC to enable the boiler
and run it at low fire, and 10 VDC to run the
boiler at high fire. Once the control enables the
boiler, it must wait 30 seconds to allow the burn-
er to stabilize before modulating the boiler.
NOTICE