Connections/Fresh Air
28
Installation Examples
(continued)
Important precautions
Avoid frequent system water
replenishment
This boiler is
not
for use in systems
where water is constantly or frequently
replenished. Minerals such as calcium in
make-up water can deposit on the heat
exchanger causing overheating, and
eventually the boiler will leak. This type
of failure is not covered by warranty.
Water must not be drained from system
for use by cleaning personnel or be
constantly replenished due to
inadequately sized expansion tanks,
flooded expansion tanks, system leaks,
etc.
Heating circuit
Spring-loaded flow check valve
Circulation pump
Safety header
with automatic air vent,
pressure relief valve, and
pressure gage
Expansion tank
Bypass (must be min. 12”/305 mm
long)
V
1
Flow regulating/throttling valve
V
2
Flow regulating/throttling valve
Oxygen diffusion barrier
underfloor tubing
The boiler warranty does
not
cover
leaks resulting from corrosion caused
by the use of underfloor plastic tubing
without an oxygen diffusion barrier.
Such systems must have
non-oxygen-diffusion barrier tubing
separated from the boiler with a heat
exchanger. Viessmann recommends the
use of underfloor plastic tubing with an
oxygen diffusion barrier.
Supply/return bypass for large water
content systems
For boilers connected to large water
content systems, such as a previous
gravity system with large free-standing
radiators, a bypass line from the supply
pipe to the return pipe can be used.
Bypass can be installed on any system
as a preventative measure.
Viessmann
strongly recommends installing a
bypass pipe on all cast iron boilers.
Install bypass as shown in order to
prevent condensation from occurring in
the heat exchanger when installing the
boiler in a large water volume
residential system (typically systems
with volume > 1 USG/3.8 ltr for every
13 000 Btu/h).
Install supply/return bypass as follows:
1.
Install full size bypass pipe (same
diameter as boiler supply and return
pipes) as shown.
2.
Install two flow regulating/throttling
valves, V
1
and V
2
, to slow down the
flow in the boiler by bypassing some
of the water back to the system.
3.
Bypass pipe must be at least
12”/305 mm long.
4.
Open valve V
1
and close valve V
2
completely.
5.
By trial and error method, gradually
open valve V
2
while regulating valve
V
1
until the boiler temperature gage
reads at least 140 ºF/60 ºC in less
than ten minutes.
5167
463
v
1.
3
V
1
V
2
Summary of Contents for Vitogas 100 GS1 Series
Page 35: ...35 5167 463 v1 3 ...
