L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT
SENSOR WIRES
Fig. 4. Replacement sensor installation.
Replacement Sensor Installation
Turn off all power and:
1. Carefully disconnect sensor from circuit board
by pulling gently on the connector.
2. Gently pull sensor from thermo well and through
circuit board by pulling on leadwires.
3. Carefully align replacement sensor with hole in
circuit board and guide through Aquastat case
and into well. (See Fig. 5).
4. Make sure sensor is fully seated to bottom of
well (See Fig. 4). Use a small pencil to measure
depth of sensor in well, if necessary.
5. Connect sensor to circuit board by pressing con-
nector on sensor unit into mating connector on
circuit board (See Fig. 5).
6. For remote sensors (flush-mounted Aquastat
Controllers) be sure to use 121571AA Clamp
(see Accessories) to securely hold sensor in
place.
THERMOSTAT
TERMINALS
T
T 3
ZR
L1
L2
C2
B2
C1
B1
ZC
Fig. 5. Circuit board, showing sensor connection and
well holes for vertical mount models.
Fuse
The 1 Amp fuse located near the transformer is
intended to protect the EnviraCOM circuit from
incorrect wiring. The Aquastat will continue to
function should the fuse blow or be removed though
no EnviraCOM communication will be possible on the
bus and Err 6 will be displayed. See Table 10.
68-0281EFS—09
BOILER
IMMERSION
SENSOR
WELL
HEAT-CONDUCTIVE COMPOUND
(OPTIONAL)
ENVIRACOM
TM
TERMINALS
2
DISPLAY
1
SENSOR
CONNECTOR
RELAYS
SENSOR HOLES
FUSE
WIRING
WARNING
Electrical Shock Hazard.
Can cause serious injury or death.
Disconnect power supply before making wiring
connections to prevent electrical shock or
equipment damage.
All wiring must comply with local electrical codes and
ordinances. Do not exceed the specifications in the
Application section when wiring this control. Use wire
M22026
rated for 194 °F (90 °C) or higher.
IMPORTANT
The terminals on these Aquastat Controllers
are approved for use with copper wire only.
Follow the appropriate wiring diagrams shown on the
inside of the front cover of the L7224A,C; L7248A,C,L
or in Fig. 8–13.
Refer to Fig. 6 for Connections for the optional
Outdoor Reset Module and the Domestic Hot Water
(DHW) module. In subsequent wiring diagrams these
modules will be displayed with a dotted line signifying
that they are optional.
ZR
L1
L2
C2
B2
C1
B1
ZC
Fig. 6. Wiring the Outdoor Reset Module and the
OPERATION
General
The L7224A,C and L7248A,C,L Oil Electronic Aquastat
M32187
Controllers are primary safety limit-rated devices
designed for use with oil fired boilers with line voltage
burners and circulators. Many boilers do not include
wiring or control compartments as part of the design,
but are provided with an integral, replaceable,
immersion well that is the mounting hardware for the
Aquastat Controllers. Wiring to the other controls is
done through flexible metal conduit.
For boilers that do include a remotely (flush) mounted
control, the wiring may be completed with conduit or
routed behind the boiler sheet metal.
4
®
CONTROLLERS
W8735Y1000 OR W8735S1000
OUTDOOR RESET MODULE
(W8735S1000 SHOWN)
1 2 3 OT OT
T
T
3
2
1
Domestic Hot Water Module.
C7089U1006
OUTDOOR
SENSOR
W8735S1008
DOMESTIC HOT
WATER MODULE
1 2 3 TS TS
32003971-003
TEMPERATURE
SENSOR
M34961