Viessmann VITOCELL 300-H User manual

Installation Instructions
VITOCELL
r
300
-H
5696 675 - 04 02/2018
for use by heating contractor
Vitocell 300-H
EHA Series
Indirect-fired domestic hot water storage tank
42 USG to 119 USG (160 L to 450 L) capacity
Read and save these instructions
for future reference.
IMPORTANT
CAUTION
The heat transfer medium must
be water or other non-toxic fluid
having a toxicity rating or class
of 1, as listed in clinical toxicology
of commercial products, 5th
edition.
This tank version is not suitable
for steam heating applications.
The pressure of the heat transfer
medium must be limited to a
max. of 30 psig by an approved
safety or relief valve.
Please file in Service Binder
Product may not be exactly as shown

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Safety, Installation and Warranty Requirements
Introduction
Please ensure that these instructions are read and understood before commencing installation. Failure to comply with
the instructions listed below and details printed in this manual can cause product/property damage, severe personal
injury, and/or loss of life. Ensure all requirements below are understood and fulfilled (including detailed information
found in manual subsections).
Licensed professional heating contractor
The installation, adjustment, service and maintenance
of this equipment must be performed by a licensed
professional heating contractor.
Please see section entitled
“Important Regulatory and Installation
Requirements”.
Product documentation
Read all applicable documentation before commencing
installation. Store documentation near product in a
readily accessible location for reference in the future
by service personnel.
For a listing of applicable literature,
please see section entitled “Important
Regulatory and Installation Requirements”.
Advice to owner
Once the installation work is complete, the heating
contractor must familiarize the system operator/
ultimate owner with all equipment, as well as safety
precautions/requirements, shutdown procedure, and
the need for professional service annually before the
heating season begins.
Warranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
CAUTION
The heat transfer medium must either be potable
water or contain only substances which are recognized
as safe by the U.S. food and drug administration.
The pressure of the heat transfer medium must be
maintained less than the normal minimum operating
pressure of the potable water system.

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5696 675 - 04
Vitocell 300-H, EHA Series Installation Contents
Safety, Installation and Warranty Requirements..............2
Licensed professional heating contractor.....................2
Product documentation.............................................2
Advice to owner......................................................2
Warranty................................................................2
Important Regulatory and Installation Requirements........4
Codes.....................................................................4
Mechanical room.....................................................4
Working on the equipment........................................4
Technical literature..................................................4
About These Instructions.............................................5
Product Information....................................................5
Tank Set-up...............................................................6
Recommended installation clearances for service access..6
Transport and Handling................................................7
Multiple Tank Set-up
[only for 92 and 119 USG (350 and 450 L)]..................8
Orientation and Dimensions..........................................9
Control Connections..................................................10
Boiler Water Connections (Heat Exchanger Connection)...11
Individual DHW Tank.................................................11
Multiple DHW Tanks
[only for 92 and 119 USG (350 and 450 L)]................12
Steam Heating Side Connections
[only for 92 and 119 USG (350 and 450 L)]................13
Individual DHW tank..............................................13
Multiple DHW tank................................................14
Domestic Water Connections......................................15
Recirculation Connections..........................................18
Pressure Drop Information..........................................19
Service...................................................................19
Introduction
Safety
General Information
Set-up
Connections
Additional Information
Page

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Vitocell 300-H, EHA Series Installation
WARNING
If the heating system itself is to be filled with Glycol or
any other antifreeze, the system fill must be of non-toxic
or food grade antifreeze. In any circumstance, a non-toxic
fluid must be used. Ensure a copy of the Safety Data
Sheet (SDS) is supplied to the operator/ultimate owner
of the system. The use of Viessmann supplied “Tyfocor-
HTL” solar fill is recommended for the solar heating
circuit.
Codes
The installation of indirect-fired hot water storage tanks
in boilers and solar system application might be governed
by individual local rules and regulations for this type of
product, which must be observed. Always use latest
editions of codes.
In the Commonwealth of Massachusetts, all plumbing
work must be done by a licensed plumber or gas-fitter
and for gas installations, all gas piping must be done by
a licensed gas-fitter.
Mechanical room
Ensure the mechanical room complies with the
requirements of the system design guideline and/or
Technical Data Manual (available from your Viessmann
sales representative).
The tank must be installed in a mechanical room which
is never subject to freezing temperatures.
Ensure water in tank is drained if not in use and danger
of freezing exists in the mechanical room.
Working on the equipment
The installation, adjustment, service, and maintenance
of this equipment must be done by a licensed professional
heating contractor who is qualified and experienced in
the installation, service, and maintenance of hot water
heating systems. There are no user serviceable parts on
this equipment.
Ensure main power supply to equipment, the heating
system, and all external controls has been deactivated.
Close main oil or gas supply valve. Take precautions to
avoid accidental activation of power during service work.
Safety
Important Regulatory and Installation Requirements
Please carefully read this manual prior to attempting
installation. Any warranty is null and void if these
instructions are not followed.
This product must be installed observing not only the
information and instruction provided in the pertinent
product literature (see list on following page), but also
all local, provincial/state plumbing and building codes,
as they apply to this product and all periphery
equipment.
For information regarding other Viessmann System
Technology componentry, please reference
documentation of the respective product (available
from your Viessmann sales representative).
We offer frequent installation and service seminars
to familiarize our partners with out products. Please
inquire.
The completeness and functionality of field supplied
electrical controls and components must be verified
by the heating contractor. These include low-water
cut-offs, flow switches (if used), staging controls,
pumps, motorized valves, air vents, thermostats,
temperature controls, etc.
Technical literature
Literature applicable to all aspects of the Vitocell:
- Technical Data Manual
- Installation Instructions
- Start-up/Service Instructions
- Operating Instructions and User’s Information Manual
Leave all literature at the installation site and advise the
system operator/ultimate owner where the literature
can be found. Contact Viessmann for additional copies.

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
About These Instructions
Product Information
Take note of all symbols and notations intended to draw attention to potential hazards or important product information.
These include “WARNING”, “CAUTION”, and “IMPORTANT”. See below.
Warnings draw your attention to the presence of
potential hazards or important product information.
Cautions draw your attention to the presence of
potential hazards or important product information.
Helpful hints for installation, operation or maintenance
which pertain to the product.
This symbol indicates that additional, pertinent
information is to be found.
This symbol indicates that other instructions must be
referenced.
WARNING
Indicates an imminently hazardous situation which, if
not avoided, could result in substantial product/property
damage, serious injury or loss of life.
CAUTION
Indicates an imminently hazardous situation which, if not
avoided, may result in minor injury or product/property
damage.
IMPORTANT

42 and 53 USG (160 and 200 L) capacity
Indirect-fired domestic hot water storage tank with one
heat exchanger coil for use with hot water heating oilers.
92 and 119 USG (350 and 450 L) capacity
Indirect-fired domestic hot water storage tank with one
heat exchanger coil for use with hot water heating
boilers, commercial heating plants, and low-temperature
heating systems (larger heating surface).
General Information

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Tank Set-up
Set-up
For narrow passageways, remove lower portion of
crating and carry DHW tank to its installation location
by means of crating boards mounted on the tank
lengthwise.
Packaged M8 bolts are necessary for the set-up of
a multiple tank installation.
Leave adequate clearance to the wall or other
objects enabling easy access to the aquastat (where
applicable).
Locate tank(s) on flooring or foundation capable of
supporting the weight of the tank(s) filled with
water.
The tank does not require a special foundation and
can be placed directly on the floor. If, for cleanliness
purposes, the tank is to be kept off the floor, a
foundation can be used for each tank or tank battery.
A minimum clearance of 17¾” (450 mm) must be
maintained at the back of the tank for the installation
of the sensor well and DHW tank temperature sensor.
Level tank using leveling bolts on tank frame.
Leveling bolt
Storage capacity USG (L) 42 (160) 53 (200) 92 (350) 119 (450)
Rear inches (mm) 18 (460) 18 (460) 18 (460) 18 (460)
Sides May be reduced if rear
pipe connections can be
reached with less clearance
inches (mm) 12 (300) 12 (300) 12 (300) 12 (300)
Top inches (mm) 12 (300) 12 (300) 12 (300) 12 (300)
Front inches (mm) 24 (600) 24 (600) 24 (600) 24 (600)
Recommended installation clearances for service access
Storage capacity USG (L) 42 (160) 53 (200) 92 (350) 119 (450)
All sides inches (mm) 0 (0) 0 (0) 0 (0) 0 (0)
Minimum clearances to combustibles

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Removing panels
1. Turn tank 90° to sit across its pallet.
2. Carefully unhook front panel.
3. Remove insulation.
4. Remove spring clip and carefully pull sensor of the
thermometer out of tank cap.
5. Remove insulation ring.
6. Pull side panels forward to remove.
7. Unscrew top panel.
Note: Only for the 92 USG (350 L)
Where access to the boiler room is difficult, remove
the front and side panels unscrew the adjustable
feet and turn the DHW tank on it’s side. This will
provide 2 in. less width.
8. Using a flat piece of wood and a rubber mallet,
carefully hammer inner front and rear panels off
the four corners and remove.
9. Move tank into mechanical room.
Transport and Handling
Set-up

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Set-up
Two tanks, each with 92 USG (350 L) content and up
to three tanks, each with 119 USG (450 L) content,
may be stacked vertically.
1. Set-up and orient lower tank in its final location.
2. Remove levelling bolts of top tank.
3. Carefully unhook front panel.
4. Remove insulation.
5. Remove spring clip and carefully pull sensor of the
thermometer out of tank cap.
6. Pull side panels of top tank forward to remove.
Multiple Tank Setup [only for 92 and 119 USG (350 and 450 L)]
1. Place top tank on top of bottom tank and align.
2. Take packaged M8 bolts, drop in holes of top tank
support brackets and fasten to bottom tank support
brackets.
3. Reinstall side panels.
IMPORTANT
Install third tank (if applicable) in an identical fashion as
the second tank.
4. Fully insert sensor into opening in tank cap and
secure using spring-clip.
5. Install insulation.
6. Install front panel.

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Orientation and Dimensions
Connections
92 and 119 USG (350 and 450 L)
42 and 53 USG (160 and 200 L)
Legend
A Domestic hot water supply, T&P valve (and
recirculation tapping) (brass tee ¾ in.)
B Boiler water supply
C Aquastat well (brass reduction coupling 1 - b in.)
E Domestic cold water supply
F Boiler water return
Legend
A T&P valve (and recirculation tapping) (brass reduction
coupling 1 - ¾ in. or 1a - ¾ in.)
B Domestic hot water
C Boiler water supply
D Aquastat well (brass reduction coupling 1 in. - b in.)
E Domestic cold water
F Boiler water return
Storage capacity USG
(L)
42
(160)
53
(200)
92
(350)
119
(450)
184
(700)
238
(900)
357
(1350)
Number of tanks 1 1 1 1 2 2 3
Layout
Connections (individual Tanks)
Heating water supply/return 7”11
1a1a1a1a1a
Domestic cold/hot water 7”¾¾
1a1a1a1a1a
Pressure and temperature relief valve 7”¾¾ 1
1a11a1a

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Connections
Control Connections
1. Install reducing coupling (included in (Connection
Fitting Package). Use approved pipe sealant.
2. Install sensor well using sealant.
Where Vitotronic 200 or 300 is utilized to control DHW
production:
3. Insert DHW tank temperature sensor (supplied with
Vitotronic 200 or 300) fully and completely into
sensor well.
Due to the length of the stainless steel well (15” (380
mm)), care must be taken to ensure that the sensing
bulb of the limit is inserted and pushed to the end of
the stainless steel well.
Where a Vitotronic 100 and a Viessmann Power/Pump
Control Module are utilized to control DHW production:
4. Insert the extended capillary of the aquastat
(supplied with Viessmann Power/Pump Control
Module, not illustrated) fully and completely into
sensor well. Mount aquastat inconspicuously on tank
paneling. Follow instructions below with regard to
sensor and spring clip installation.
...if aquastat is to be mounted remote from the
aquastat well:
5. Align sensor bulb with spring clip.
6. Slide assembly into well.
7. The retention spring clip must press the bulb
properly to ensure surface contact with the well.
... if aquastat is to be mounted directly on the tank
well,
8. Mount aquastat with holding clip supplied directly
onto well. Bend capillary tube into groove opening
to allow for mounting of aquastat.
IMPORTANT
WARNING
To ensure optimum, safe operation, the supplied
stainless steel well must be installed. The well
diameter is large enough to accommodate a wide
variety of sensing bulbs.
Always use spring clip to ensure proper contact of
capillary bulb against the stainless steel well for
proper sensing/heat transfer!
Not present on 42 and 53 USG
(160 and 200 L) version

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Vitocell 300-H, EHA Series Installation
Boiler Water Connections (Heat Exchanger Connection)
DANGER
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
scalded. 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).
Connections
Maximum working pressure on heat exchanger side
up to 220 psig at 392°F (200°C) or a steam
pressure of 15 psig at 250°F (121°C)
Maximum working pressure on DHW water side
of up to 150 psig at 210°F (99°C)
1. Pipe together boiler and tank as illustrated.
Connections must be accessible for 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 119 USG (350 and 450 L) tanks:
Remove plastic supply and return grommets
(grommets are left threaded).
3. Pipe supply line with an incline and install
componentry as follows:
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 10).
6. Insulate piping.
WARNING
The operating aquastat and any secondary high limit aqua-
stat of the tank must be set such that the DHW
temperature inside the tank never exceeds 210°F (99°C).
Individual DHW Tank
Legend
A Vitocell 300
B Sensor/Operating aquastat well
C Automatic air vent
D Spring-loaded flow-check valve
E Circulation pump
F Boiler water supply
G Boiler
H Boiler water return
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.
IMPORTANT
Recommended piping of an individual tank
flow check valve, to stop gravity circulation of hot
water back to the boiler when the boiler temperature
is lower than the actual tank temperature
automatic air vent, at the high point from the boiler
supply to the tank heat exchanger
drain valve, on the boiler return piping from the
tank heat exchanger coil
isolation valve, on the boiler supply and boiler
return piping to the tank coil.

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
All piping reverse return or use balancing valves.
1. Pipe together boiler (not shown) and tanks as
illustrated. Connections must be accessible for
service (use factory supplied adaptors).
2. For boiler water supply temperatures over 203°F
(95°C):
Remove plastic supply and return grommets
(grommets are left threaded).
3. Pipe supply line with an elevation and install an
automatic air vent at the highest point.
4. Install boiler sensor in sensor well (see page 10).
5. Insulate piping.
The circulation pump is activated by the sensor /
operating aquastat and by the control system installed.
The operating aquastat should be mounted on the tank
which receives the boiler water supply last.
Viessmann recommends the installation of an additional
high limit aquastat in the main discharge pipe of the
DHW system.
This aquastat should be wired in series with the
operating aquastat and should be set approximately
9°F (5°C) higher than the operating aquastat.
IMPORTANT
Legend
AVitocell 300-H F 1a” *1
BBoiler water supply G 2” *1
CBoiler water return H 3” *1
E Operating aquastat K 4” *1
L 5” *1
*1Pipe size for boiler supply and return to heat exchanger.
Multiple DHW Tanks [only for 92 and 119 USG (350 and 450 L)]
DHW tank battery with
2 x 357 USG
(2 x 1350 L)
(2 x triple cell)
WARNING
Install tempering valve(s) to protect against scalding.
WARNING
Do not stack more than three tanks. Stack only tanks of
identical size.
DHW tank battery with
357 USG (1350 L )
or
276 USG (900 L)
(triple cell)
Connections
DHW tank battery
with 184 or 238 USG
(700 or 900 L)
(dual cell)
DHW tank battery with
2 x 184 or 2 x 238 USG
2 x (700 or 2 x 900 L)
(2×dual cell)

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Vitocell 300-H, EHA Series Installation Connections
Steam Heating Side Connections [only for 92 and 119 USG (350 and 450 L)]
WARNING
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).
Do not use Vitocell indirect-fired hot water storage
tanks in superheated steam applications.
Use appropriate control strategy.
Control strategy must ensure that the values below are
not exceeded.
Install a steam-side control to regulate DHW
temperature and ensure that the DHW
temperature does not exceed 210°F (99°C).
Maximum working pressure on heat exchanger
side up to 220 psig at 392°F (200°C) or a steam
pressure of 15 psig at 250°F (121°C)
Maximum working pressure on DHW water side of
up to 150 psig at 210°F (99°C)
WARNING
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
scalded.
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).
1. Pipe steam and condensate lines as illustrated.
Connections must be accessible for service (use
factory supplied adaptors).
2. Remove plastic grommets on tank where condensate
lines connect (grommets are left threaded).
3. Install DHW tank temperature sensor in sensor well;
install steam valve.
4. Insulate piping.
Installation Instructions Control Valve
CAUTION
For steam applications, a field supplied 1” T&P valve
must be utilized.
Legend
A Vitocell 300-H
B Sensor/Aquastat well
C Vacuum breaker
D Steam valve
E Steam supply line
F Condensation return line
G Condensate trap
Recommended piping of an individual tank in a steam system
Individual DHW tank
Note: For heating water flow temperatures above
203°F (95°C), remove the pipe collars from
the pipe outlets of the heating coils (pipe collars
have left hand threads).

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Vitocell 300-H, EHA Series Installation
Steam Heating Side Connections [only for 92 and 119 USG (350 and 450 L)] (continued)
IMPORTANT
WARNING
Do not stack more than three tanks. Stack only tanks of
identical size.
To ensure uniform heating of domestic hot water
within each tank battery, install domestic hot water
recirculation as illustrated on page 18.
Cap any unused recirculation connection on each tank.
Follow the control and safety recommendations of the
respective steam boiler manufacturer.
Legend
A Vitocell 300-H
B Condensate trap
C Sensor/Aquastat well
D Steam supply
E Steam valve
F Vacuum breaker
G Condensate line
The following installation is also subject to local codes
and requirements:
The following installation is also subject to local codes
and requirements:
- Install a steam valve and vacuum breaker between
steam supply line and each tank.
Install a drain with a condensate trap at the end of
the steam supply line to each steam valve.
Install a condensate trap on each heat exchanger
outlet before connecting all condensate lines to a
common condensate return line.
or
- Install a steam valve in the common steam supply
line.
Install a vacuum breaker after the steam valve.
Install a drain with a condensate trap at the end of
the steam supply line to each steam valve.
Install a condensate trap on each heat exchanger
outlet before connecting all condensate lines to a
common condensate return line.
All piping reverse return.
1. Pipe together steam and condensate lines as
illustrated. Connections must be accessible for
service (use factory supplied adaptors).
2. Remove plastic grommets on each tank where steam
and condensate lines connect (grommets are left
threaded).
3. Install an approved type high limit aquastat for
temperature control of domestic hot water on each
tank.
4. Install aquastat temperature sensor in sensor well;
install steam valve.
5. Insulate piping.
Recommended piping of a tank battery in a steam system
Multiple DHW tank
Connections

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5696 675 - 04
Vitocell 300-H, EHA Series Installation Connections
Domestic Water Connections
Legend
A Domestic hot water
B 1a" *1
C 1b” *1
D Domestic cold water
E 2"*1
F 2b”*1
G Secondary high limit aquastat
*1Pipe size for domestic cold and hot water piping.
DHW tank battery
with 184 and 238 USG
(700 and 900 L)
(dual cell)
DHW tank battery with
2 x 184 and 2 x 238 USG
2 x (700 and 2 x 900 L)
(2 x dual cell)
DHW tank battery with
2 x 357 USG
2 x (1350 L)
(2 x triple cell)
Ensure that local rules and regulations regarding this
type of product have been observed.
1. Pipe boiler and tank as illustrated. Connections must
be accessible for service (use factory supplied
adaptors).
2. Insulate domestic hot water piping and valves.
IMPORTANT
In order to avoid temperature stratification Viessmann
recommends the use of a small recirculation pump
between the DHW supply point A and the DCW
supply point D in multiple tank arrangements.
The recirculation pump will only operate when there
is no DHW draw from the tank batteries.
DHW tank battery with
357 USG (1350 L)
(triple cell)

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Vitocell 300-H, EHA Series Installation
Domestic Water Connections (continued)
42 and 53 USG (160 and 200 L) capacity
92 and 119 USG (350 and 450 L) capacity
Legend
A Domestic hot water supply
B DHW recirculation line
Crecirculation pump
D Spring loaded check valve
E Discharge pipe
F Pressure and temperature relief valve
G Shut-off valve
H Drain
K Domestic cold water supply lines
L Back-flow preventer
M Domestic cold water inlet
N Precharged expansion tank
(required where back-flow
preventer is installed; check local
plumbing codes and requirements)
Connections

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Vitocell 300-H, EHA Series Installation Connections
Domestic Water Connections (continued)
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 tank instruction manual.
- The discharge line from the T&P valve shall be ¾ in.
(1.9 cm)
7and 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 as short as possible and
pitch downward from the T&P valve and terminate plain
not threaded.
Always ensure the use of approved devices.
Safety devices include the following components:
- Isolation valves
- Drain valve
- Pressure reducing valve
where required by local jurisdiction
- Drinking water filter
where required by local jurisdiction
- Backflow 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 backflow device must be installed
according to the manufacturer’s installation
instructions. Observe local codes and regulations.
- 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.
IMPORTANT
In situations where a booster pump is used to maintain
DHW pressure, Viessmann strongly recommends the
installation of an oversized large expansion tank to
ensure longer, less frequent pump cycles with less severe
pressure gradients. If possible, use flexible piping before
and after booster pump to isolate system piping from
vibration and shocks.
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
The discharge line for the T&P valve must be oriented to
prevent scalding of attendants.
- Do not route discharge line directly to the outdoors.
- Do not install any type of valve or restriction of any
kind between the tank and the T&P valve, or
between the T&P valve and the discharge line outlet.
- 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 a maximum operating
pressure of 150 psig.
The T&P 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.
T&P Valve set pressure 150 psig
ASME pressure steam rating see ratings marked on
the T&P valve
CSA discharge capacity 205 MBH
Relief temperature 210°F (99°C)
Inlet thread c” male
Outlet thread c” female

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5696 675 - 04
Vitocell 300-H, EHA Series Installation
Connections
Connection of a recirculation system in a multiple
tank installation for systems utilizing boilers or remote
heating plants without low temperature boiler return
water and for steam heating operation with 15 psi and
one recirculation line.
Connection of a recirculation system in a multiple
tank installation for remote heating plants with low
temperature boiler return water limit and/or for multiple
recirculation lines.
Recirculation Connections
Legend
A Domestic hot water
B Recirculation circuit
CDomestic cold water
Legend
A Domestic hot water
B Recirculation circuit
CDomestic cold water
Pipe domestic hot water supply piping with tank as
illustrated. Connections must be accessible for service
(use factory supplied adaptors). Connection sizes are
provided in section entitled Orientation and
Dimensions on page 9.
Install recirculation pump, flow-check valve and
recirculation timer (for shut-down during off-hours
where feasible) on the recirculation piping side.
Gravity circulation of the recirculation system is
restricted due to the upward-curved domestic hot
water discharge piping inside the tank.
Connect tank battery to existing recirculation piping.
Cap off unused recirculation connections of
individual tanks.
Saving Energy
A timer on the recirculation pump reduces the heat loss
significantly in commercial applications during times when
no or reduced demand for domestic hot water occurs.
Legend
A 42 and 53 USG (160 and 200 L) storage capacity
B 92 and 119 USG (350 and 450 L) storage capacity
Recirculation tapping
[only for 92 and 119 USG (350 and 450 L)]
The recirculation tapping on the tank is also the opening
for mounting the temperature and pressure relief valve
(T&P valve).
If this opening is utilized for recirculation, extend the
stainless steel nipple on the tank with a brass tee
(field supplied) of the same size as the stainless steel
nipple diameter to accommodate both connections.

19
5696 675 - 04
Vitocell 300-H, EHA Series Installation
Pressure drop on domestic hot water side (secondary circuit) Pressure drop on heating water side (primary circuit)
Legend
A 42 and 53 USG (160 and 200 L) storage capacity
B 92 and 119 USG (350 and 450 L) storage capacity
Legend
A 42 USG (160 L) storage capacity
B 53 USG (200 L) storage capacity
C 92 USG (350 L) storage capacity
D 119 USG (450 L) storage capacity
Pressure Drop Information
Additional Information
For start-up information refer to
the Start-up/Service Instructions
DHW Tank.
Service
1. File all Parts Lists, Operating and Service
instructions in the Service Binder.
2. Install a protective hanging case near the boiler and
store the Service Binder in this location.
For a listing of applicable Viessmann literature, please
see Important Regulatory and Installation Requirements.

5696 675 - 04
Vitocell 300-H, EHA Series Installation
Technical information subject to change without notice. Printed on environmentally friendly
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