
System Design Guidelines
24
Ø19
Ø17
10 VITOCELL 300-B
Sensor well
he supplied stainless steel sensor wells are
to be used for control sensors to ensure
maximum operational safety. he top sensor
well is used for the DHW sensor connected
to the boiler control.
Should the supplied sensors not fit into the
sensor wells, other stainless steel sensor
wells must be used.
For solar heating systems, Viessmann
recommends placement of the DHW tank
temperature sensor in the solar collector
return. his requires a brass elbow with
sensor well included in the accessory pack
(see pg. 8).
Dimensions
capacity
USG /
ltr
79 /
300
120 /
450
a
b
inches
mm
inches
mm
8.7
220
7.9
200
13
330
12¼
310
Heating water s pply temperat re
over 230ºF / 110ºC
hese operating conditions require the
installation of an additional safety high limit
into the DHW storage tank, preventing the
temperature from rising above 203ºF /
95ºC. A domestic hot water tempering
valve must be used.
Temperat re and press re
relief valve
A temperature and pressure relief valve
( &P relief valve) is supplied with the tank.
he heating contractor must install the
valve on each tank in a method meeting
code requirements. If local codes require a
different relief valve, substitute the
manufacturer’s supplied valve. he tank is
approved for 100 psig where a CRN is
required. Maximum operating pressure is
150 psig.
he &P relief valve supplied with the tank
is tested under ANSI Z21.22 Code for Relief
Valves and Automatic Gas Shut-off Devices
for Hot Water Supply Systems.
Backflow preventers
Where backflow preventers are required, a
domestic water expansion tank installation
is recommended in the cold water inlet
piping before the cold water enters the
Vitocell. For the backflow device, observe
local plumbing codes and regulations.
Watts Model
40XL-8
100 psig
(Canada
where
CRN is
req ired)
150 psig
(US and
Canada)
ASME pressure
steam rating
998 MBH 1438 MBH
CSA temperature
steam rating
205 MBH
Relief
temperature
210ºF (99ºC)
Inlet thread
¾” male
Outlet thread
¾” female
Warranty excerpt
Our warranty for domestic hot water tanks
states that the water to be 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 assured. In the
event that Viessmann non-approved
components are utilized, Viessmann reserves
the right to withdraw all expressed or implied
warranties without written notice.
he 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.
he 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.
For full warranty details, please read the
product warranty card.
To ens re optim m, safe operation, the
s pplied stainless steel well m st be
installed. The well diameter is large
eno gh to accommodate a wide variety
of sensing b lbs.
Always se spring clip to ens re proper
contact of capillary b lb against the
stainless steel well for proper
sensing/heat transfer!
WARNING