Installation & Servicing instructions ATAG iS-Range
20
2 port zone valve & dual thermostat (supplied with unvented cylinder)
The 2-port zone valve must be installed in the primary flow pipework between the 3-port valve and the
cylinder connection as per the following diagram and G3 unvented hot water requirements.
The 230v mains power supply MUST be wired only to the high limit thermal cut-out of the dual thermostat
and be wired to interrupt the power to the motor of the 2-port valve as per electrical diagram below.
3-port diverter valve
Install the 3-port diverter valve on the system pipework with the valve ports is the following orientation, AB
port iS System boiler, A port hot water cylinder & B port heating system.
a.
d.
c.
a.
b.
c.
B
A
AB
AB
B
AB
A
B
A
a. brown
b. blue
c. black
d. grey
Junction box (not included)
3-port valve
230V
AB: iS System boiler
A: DHW Cylinder
B: Heating system
ATAG outside sensor (optional)
Cylinder sensor
ATAG One controller
1
2
3
4
5
6
7
8
9
10
11
12
Volt free
terminals
DO NOT CONNECT 230 VOL
T
Figure 9.6.d
Figure 9.6.c
M
N
L
N
L
N
L
E
Safety limit
thermostat
Dual thermostat
Cylinder
thermostat
NOT REQUIRED
USE CYLINDER
SENSOR SUPPLIED
Remove any links between
safety limit thermostat and
cylinder thermostat within the
dual thermostat
Boiler
mains in
230 V Mains
supply