Technical data

Connections
Fig 9.
Recommended piping of an individual tank
14
Boiler Water Connections (heat exchanger connection)
H Maximum working pressure on heat
exchanger side up to 220 psig at
392°F / 200°C or a steam pres s ure of
15 psig at 250°F / 121°C
H Maximum working pressure on DHW
water side of up to 150 psig at
210°F / 99°C
Individual DHW tank
Vitocell 300
Sensor/Operating aquastat well
Automatic air vent
This is a simplified conceptual drawing
only! Piping and necessary componentry
must be field verified. Proper installation
and functionality in the field is the
responsibility of the heating contractor.
Spring-loaded flow-check valve
Circulation pump
Boiler water supply
Boiler
Boiler water return
Use hemp and pipe dope on all threaded
stainless steel nipples on tank.
1. Pipe together boiler and tank as
illustrated. Connections must be
accessible f or service (use factory
supplied adaptors). We recommend
using Viessmann Flexible Piping of
stainless steel (accessory).
2. For:
- boiler water supply temperatures
over 203°F / 95°C and
- 92 and 120 USG / 350 and 450 ltr
tanks:
Remove plastic supply and return
grommets (grommets are left
threaded).
3. Pipe supply line with an incline and
install componentry as follows:
H flow check valve, to s t op gravity
circulation of hot water back to the
boiler when the boiler temperature is
lower t han the actual tank
temperature
H automatic air vent, at the high point
from the boiler s upply to the tank heat
exchanger
H drain valve, on the boiler return piping
from the tank heat exchanger coil
H isolation valve, on t he boiler supply
and boiler return piping to the tank
coil.
4. Protect all domestic hot water
drawpoints from excessive water
temperatures via a tempering valve.
5. Install DHW tank temperature sensor
in sensor well (see page 13 or 14).
6. Insulate piping.
5167 535 v1.3
Domestic hot water temperatures
over 125°F / 52°C can cause severe
burns instantly or death from scalds.
Children, disabled and elderly are at
highest risk of being s calded.
Feel water before bathing or
showering.
Temperature limiting valves are
available and must be used where
domestic hot water storage tank
temperatures exceed 140°F / 60°C.
DANGER
The operating aquastat and any
secondary high limit aquastat of the
tank must be set such that the DHW
temperature inside the tank never
exceeds 210°F / 99°C.
WARNING
IMPORTANT IMPORTANT