Connections
20
Domestic Hot Water Connections
(continued)
Always ensure the use of type approved devices. Safety devices include the following components:
Use Loctite 55 on all threaded steel
nipples on tank.
H
Isolation valves
H
Drain valve
H
Pressure reducing valve
where required by local jurisdiction
H
Drinking water filter
where required by local jurisdiction
H
Back flow preventer
Where backflow preventers are
required, a domestic water expansion
tank installation is required in the cold
water inlet piping before the cold
water enters the tank. The back flow
device must be installed according to
the manufacturer’s installation
instructions. Observe local codes and
regulations.
H
Tempering valve
A tempering valve must be field
installed where storage tank
(domestic hot water temperature)
exceeds local restricted temperatures
or 140°F / 60°C. Check code
requirements.
Temperature and pressure
relief valve
A temperature and pressure relief valve
(T&P valve) is supplied with the tank.
The heating contractor must install the
valve on each tank in a method meeting
code requirements.
If local codes require a different relief
valve, consult Viessmann
Manufacturing for a substitute valve.
The tank is approved for 150 psig.
Maximum operating pressure is 150
psig.
The T&P valve supplied with the tank is
manufactured by Watts Industries
(Model 40XL-8), set to 150 psig for US
and Canadian installations. The valve is
ASME pressure steam rated for 998
MBH and CSA temperature steam rated
for 200 MBH.
It is tested under ANSI Z21.22 Code for
Relief Valves and Automatic Gas
Shut-off Devices for Hot Water Supply
Systems. The relief temperature is set
at 210°F / 99°C. The valve has a male
threaded inlet and female threaded
outlet, both ¾” sizes.
Proper installation of the T&P valve
shall include all of the following:
- The T&P valve shall be installed in the
pipe connection point marked TPV in
the Installation Fittings Installation
Instruction Supplement of the tank.
- The discharge line from the T&P valve
shall be ¾” / 1.9 cm
∅
and run to a
safe place of discharge approximately
1 ft / 30 cm above the floor, close to
a floor drain.
- The discharge line must be installed in
the shortest distance and pitch
downward from the T&P valve and
terminate plain.
- Do
not
route discharge line to the
outdoors.
- Do
not
install any type of valve or an
obstruction of any kind between the
tank and the T&P valve, or between
the T&P valve and the discharge line
outlet.
Warranty
Our warranty for domestic hot water
tanks states that the water heated
must be of drinking (potable) water
quality and that any water treatment
equipment in use must function
correctly.
Viessmann accepts no responsibility for
damage howsoever caused and
reserves the right to withdraw the
product warranty if the product has
been improperly installed or misapplied
by the installer, contractor or final user.
In order to qualify for product warranty,
strict adherence to the installation and
service manuals must be observed. In
the event that Viessmann non-approved
components are utilized, Viessmann
reserves the right to withdraw all
expressed or implied warranties without
written notice.
The water to be heated with the
Vitocell must be drinking (potable)
water quality. If the tank is used to heat
other media, the warranty will be null
and void. Damage resulting from
excessive pressure or temperature is
clearly not the responsibility of
Viessmann.
The amount of chloride and sulfate
acceptable to the tank is limited. In
areas where high concentrations of
chloride and sulfate are present in
drinking water, please consult
Viessmann for directions.
5
1
6
7
5
1
9
v
2
.2
IMPORTANT
The discharge line for the T&P valve
must be oriented to prevent scalding
of attendants.
WARNING
The valve test lever must be operated
at least once per year by the owner
to ensure that waterways are clear. A
licensed professional heating
contractor shall reinspect the T&P
valve at least once every three years.
Failure to inspect can result in unsafe
temperature or pressure build-up,
which can result in death, serious
injury or substantial product/property
damage.
WARNING
