6
THERMOSTAT REQUIREMENTS
K6
K7
R6
R7
C7
+
C6
+
D11
D12
D10
D6
D4
D9
D5
D3
D21
D22
D20
D19
C
W
Y
R
ZONE 2
T'STAT
C
W
Y
R
R1
0
B
G
ZONE 1
T'STAT
CAUTION
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX 732-446-5362
ZONE 1
C
R
BY
W/E
ZONE 1 THERMOSTAT – MODEL EWT-725
G
W2
O
C
RC
BYW
ZONE 2 THERMOSTAT – MODEL EWT-601-2
G
RH
O
If the application is heat only, cool only or using the MCS-DXB
remote system selector switch, all thermostats must be set
to the same mode of operation at all times.
Zone 2 and Zone 3 thermostats must be in the same mode
(Heat or Cool) as the Zone 1 thermostat.
3
The Zone 1 (Master) thermostat must be set to heat or cool mode,
in order for Zone 2 or Zone 3 to function! If Zone 1 is turned “OFF”
Zone 2 and Zone 3 cannot function.
6 WIRES REQUIRED
MANUFACTURER
DIGITAL NON-
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
DIGITAL
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
EWT-725
Not Available
Not Available
EWC
CONTROLS
EMERSON
HONEYWELL
Not Available
Not Available
EWT-601-2
ZONES 2 & HIGHER
3 WIRES REQUIRED
DIGITAL NON-
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
DIGITAL
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
EWT-725
EWC
CONTROLS
EMERSON
HONEYWELL
Not Available
Not Available
EWT-601-2
MANUFACTURER
WiFi
Thermostats
(Hardwired)
Not Available
Not Available
Not Available
NOTES
Not Available Not Available
4
Manufacturers have been phasing out thermostat designs with
separate O & B terminals for many years now. Thermostats that are
compatible with the ST series controller are increasingly difficult
to find. As a result, the ST series zone control will soon phase out
as well. We suggest upgrading to our model NCM300 zone control,
which is compatible with 99% of the thermostats available
in today’s market. Including popular WiFi thermostats.