Advertisement
System Layout 1
Vitodens 200 (model WB2 6-24C) with a direct-connected heating circuit
PRV 1
PRV 2
DHW
DCW
WSE
IMPORTANT
The low-loss header cannot be used with
the Vitodens 200 Combi Series boiler, WB2
6-24C. The WB2 6-24C is specifically
designed for small, "one-temperature"
apartments or bungalows, where flow and
head requirements are low and can be
handled by the built-in heating circuit pump.
IMPORTANT
Do not use the expansion board to control a
separate system heating circuit pump with
Vitodens 200 Combi Series boiler, WB2
6-24C.
A heating circuit pump controlled by an
expansion board will run as a DHW
recirculation pump in parallel to the demand
for domestic hot water rather than as
intended.
AV
E2
E1
Upon a call for DHW, the built-in diverting
solenoid valve is energized. The boiler hot
water is diverted to the DHW loop at
maximum pump rotational speed (no
variable speed pump operation during DHW
production). Once the DHW instantaneous
plate heat exchanger is satisfied, the built-in
diverting solenoid valve is de-energized and
heating operation resumes.
Installation Examples
AV
Air vent
DCW Domestic cold water
DHW Domestic hot water
PRV 1 Pressure relief valve (30 psig)
PRV 2 Pressure relief valve (150 psig)
WSE
Water softening equipment/filter
Vitodens 200 gas-fired Combi
boiler
Heating circuit
Remote control for Comfortrol
programming unit
Outdoor temperature sensor of
control unit for
weather-responsive operation
Precharged expansion tank
E1
Precharged expansion tank (required
E2
where backflow preventer is
installed; check local plumbing codes
and requirements).
Expansion tank pressure rating must
be greater than 150 psig and
suitable for potable water
applications.
The built-in plate heat exchanger is
equipped with two independent temperature
safety features, one surface-mounted limit
temperature switch on the heating boiler
side and one temperature immersion control
sensor on the DHW side.
33
Advertisement
