70
5784 568 - 18
Vitodens 100-W, B1HA/B1KA 26 to 125 Combi Installation/Service
Legend
A
Viessmann outdoor temperature sensor (OTS)
(field wiring)
B
OpenTherm (OT) or room thermostat(s)
C
Connection cable terminal
D
Power terminal block 120V
E
Power supply 120V
F
Power supply accessories 120V
%
DHW tank temperature sensor (B1HA only)
or
aquastat
Note:
When using the operating methods ‘operation
without room temperature thermostat(s)’ or ‘weather
compensated operation without room temperature
thermostat’ a jumper is installed, on terminals 1-2
B
,
refer to the operating instructions.
For accessing electrical connections refer to information
starting on page 36.
Electrical Connections to the Terminal Strip for Accessories
Additional Information
Follow the installation instructions of field supplied
operating controls.
What is OpenTherm (OT)?
The OpenTherm (OT) protocol is a point-to-point
communication system, which connects a boiler with a
room controller or other devices. The room unit calculates
a heating demand (water temperature request) and
transmits it to the boiler. The boiler will adjust the heat
input accordingly (low-high modulation).
The Viessmann Input Module is designed to accept a
0-10(VDC) modulating input signal from a boiler reset
module controller and send this signal to the Vitodens
100-W with OpenTherm communication.
OT-Devices
Boiler control
Boiler reset
module (0-10V
controller)
