Domestic Hot Water Production; Domestic Hot Water Recirculation - Viessmann VITODENS 222-F Technical Data Manual

Vitodens 222-F, B2TA 19 and 35 Technical Data

Domestic Hot Water Production

The Vitodens 222-F storage combi-boiler combines
the benefits of the Vitodens 200-W with high DHW
convenience of a separate integral stainless steel DHW
storage tank.
The Vitodens 222-F uses an integrated 26.5 USG (100 L)
DHW storage tank and a DHW production pump.

Domestic Hot Water Recirculation

IMPORTANT
A diaphragm expansion tank is integrated into the
Vitodens 222-F, with a capacity of 3.2 USG (12 L) and
a pre-charge pressure of 12 psig.
Determine the required size of the expansion tank to be
installed in the heating system. If the integral expansion
tank is insufficient, install a suitably sized expansion tank
on site.
DHW recirculation lines increase the level of comfort and
convenience of the domestic hot water supply and reduce
water consumption.
These advantages directly derive from the immediate
availability of domestic hot water at all draw points.
Poor insulation of the DHW recirculation line, however,
can result in considerable heat loss. Viessmann therefore
recommends that effective insulation be provided and
used for DHW recirculation lines of 23 ft. (7 m) in length
or longer.
DHW Production
11