17
H
H
High Voltage
120
V.A.C.
24
V.A.C.
Room
Thermostat
Room
Thermostat
Zone 1
Zone 2
Additional zones
Additional zones may
be added as shown above
To HM
"Room Thermostat"
Snap Set
Transformer
(Power)
Zone
Valve
Zone Valve
C
1
INSTALLATION
To HM
"Room Thermostat"
Snap Set
H
H
High Voltage
120
V.A.C.
24
V.A.C.
Room
Thermostat
Room
Thermostat
Zone 1
Zone 2
Additional zones
Additional zones may
be added as shown above
Transformer
(Power)
Zone
Valve
Zone Valve
* Isolation relay
1
C
4 Wire Zone Valve
3 Wire Zone Valve
Fig. 16: Multiple zone field wiring using zone valves
*
Use isolation relay on 3-wire
zone valve with non-isolated
end switch. Transformer and
combination heater control
can burn out if isolation relay
is not used.