Boiler With Low Water Cut-Off; Venting Connection - Viessmann VITOCROSSAL 300 Installation Instructions Manual

Vitocrossal 300 CU3A 26 to 57 Installation

Boiler with Low Water Cut-off

Venting Connection

WARNING
Failure to ensure that all flue gases have been safely
vented to the outdoors can cause property damage,
severe personal injury, or loss of life. Flue gases may
contain deadly carbon monoxide.
Boiler with low water cut-off (remote-mounted,
field supplied)
A low water cut-off may be required by local codes.
If boiler is installed above radiation level, a low water
cut-off device of approved type (field supplied) must be
installed in all instances at the highest point of the piping
system. Do not install an isolation valve between boiler
and low water cut-off.
Follow the installation instructions of the
low water cut-off from the manufacturer.
For low water cut-off wiring information specific to your
application, refer to applicable wiring diagram (see page 50).
Performing a boiler pressure test
The boiler must be leak tested before being placed in
operation. Before boiler is connected to piping or electrical
power supply, it must be hydrostatically pressure tested.
1. After installing safety devices (see previous page),
install temporary cap on ¾ in. x 2 in. nipple.
2. Cap supply and return connections.
3. Connect ½ in. garden hose to boiler fill valve at
the bottom of the boiler and fill boiler slowly until
pressure gage indicates max. 60 psig (4 bar).
4. Maintain pressure for 15 minutes. During time of
pressure testing, do not leave boiler unattended.
5. Inspect all pipe joint connections and safety devices
with a flashlight for leaks. A lower manometer
reading than 60 psig (4 bar) usually indicates loss of
water due to leakage. All leaks must be repaired.
6. After 15 minutes, release water pressure from boiler
by opening boiler drain valve slowly, remove caps
from supply and return connections as well as ¾ in.
cap from 2 in. nipple, and install pressure relief valve
immediately instead of ¾ in. cap.
7. After boiler has passed pressure test, proceed with
the installation.
CAUTION
Under certain climatic conditions some building materials
may be affected by flue products expelled in close
proximity to unprotected surfaces. Sealing or shielding of
the exposed surfaces with a corrosion resistant material
(e.g. aluminum sheeting) may be required to prevent
staining or deterioration. The protective material should
be attached and sealed (if necessary) to the building
before attaching the vent termination. It is strongly
recommended to install the vent termination on the
leeward side of the building.
Vitocrossal 300 CU3A Installation Instructions
Venting System
Installation Examples
49