Part number 550-143-010/1021
56
GV90+
series
2
gas-fired water boiler – boiler manual
Figure 66
Field wiring connections — service switch and thermostat (or end switch) provided by installer
Thermostat wires are labeled “T-T” on boiler. Remove label
before connecting as shown in Figure 66. Route this wiring
through the hole in the upper left side jacket.
For zoned systems, substitute the zone valve end switches or
circulator relay contacts for the thermostat contact shown in
Figure 66.
DHW
Connect the DHW aquastat as shown in wiring above. The
Economy function of the control is not utilized with DHW
input.
R & C Connections
24 Vac should be used for additional thermostat power only !
Other devices requiring 24 Vac should have sepa-
rate power supply.
Wiring multiple zones
Refer to zone valve manufacturer’s literature for wiring and
application. A separate transformer is required to power zone
valves. Zoning with circulators requires a relay for each circulator
.
When using three-wire zone valves, take care to
avoid mis-wiring. This can impose an additional
24 volts across the boiler control circuitry. The IBC will sense
this problem and lockout. It will flash the POWER and TSTAT
CIRC lights to indicate the problem. See label on IBC for expla-
nation of lockout conditions. To verify before connecting to
boiler, disconnect field thermostat wires at boiler. Place a volt-
meter across the leads. Then watch the voltmeter as each zone is
activated (by activating zone thermostat). There should never be
a voltage reading across the two leads coming to the boiler. If you
see a voltage reading, one or more zone valves is mis-wired.
Carbon monoxide detector
For
Direct Exhaust
units, a carbon monoxide
detector is required in the boiler room. The
carbon monoxide detector must be wired on the
same electrical circuit as the boiler. For
Direct
Vent
units, a carbon monoxide detector that is
wired on the same electrical circuit as the boiler
is strongly recommended.
Wiring
(continued)
Figure 67
Wiring location for additional limit controls
