Viessmann B2HA 80 User manual

Installation Instructions
5698 072 - 02 08/2017
Heat Exchanger Assembly
for use by heating contractor
for Vitodens 200-W WB2B / B2HA
Part Number: 7831454 WB2B 80, 105
Part Number: 7843753 B2HA 80, 88, 100, 285, 311, 352
Refer to the Installation and Service
Instructions applicable to this boiler.
Ensure that main power to the equipment being serviced
is off.
Ensure that the main fuel supply valve to the boiler is
closed.
Take precautions to avoid accidental activation of power
or fuel during service work.
Do not perform service work on any component part
without ensuring safe operation of the heating system.
When replacing parts, use original Viessmann or
Viessmann approved replacement parts.
Safety and Installation Requirements
Please ensure that these instructions are read and
understood before starting any service work. Failure to
comply with these instructions may cause product/property
damage, severe personal injury and/or loss of life.
Working on the equipment
The installation, adjustment, service and maintenance of
this product must be performed by a licensed professional
heating contractor who is qualified and experienced in
the installation, service, and maintenance of hot water
boilers. There are no user serviceable parts on the boiler,
burner or control.

2
5698 072 - 02
Heat Exchanger Assembly Installation
Accessing the Heat Exchanger
1. With the electrical power and fuel supply off, open
the control cover and switch the ON/OFF
boiler
control switch to OFF.
2. Remove the front enclosure panel.
3. Close the boiler isolation valve or drain the system.
4. Remove the burner assembly.
Replacing Supply Pipe/Sensors/Refractory
For more details refer to the Installation and
Service Instructions applicable to this boiler.
1. Remove the Torx screw G(T-25) with the washer
and pull the refractory Hstraight out.
2. Disconnect electrical connectors from the heating
supply pipe A.
3. To replace the following:
- Remove connecting clip for boiler temperature sensor B.
- Remove 2 Phillips screws for high limit sensor C.
4. Pull off the connecting clip Eto disconnect the
pressure gauge hose from the heating supply pipe A.
5. Remove the two Torx screws (T-40) Dat the top
and loosen the compression fitting at the bottom on
the heating supply pipe Aand remove pipe with top
O-ring F.
6. Replace parts as required and reassemble as per steps
5 through 1 respectively and torque fasteners per
legend.
Legend
Tighten the following fasteners on assembly:
C8.9 lb.in. (1 Nm)
D70.8 lb.in. (8 Nm)
G35 lb.in. (4 Nm)

3
5698 072 - 02
Heat Exchanger Assembly Installation
Replacing Heat Exchanger/Return Pipe
1. Drain water from the heat exchanger
through the sediment faucet drain valve.
Residual water may leak out during disassembly.
IMPORTANT
2. Remove supply pipe (see Replacing Supply Pipe).
3. Remove the two Phillips screws Aunder the control
console and slide out. Disconnect all wiring
connectors, remove console and set aside.
IMPORTANT
The control console must be removed to protect it from
accidental water spillage.
4. Loosen by hand and remove the condensate hose B.
5. Disconnect the flue gas temperature sensor plug inside
the boiler from the vent pipe adaptor C.
6. Remove the four Allen screws (4 mm) Dand
disconnect the vent pipe adaptor Cfrom the heat
exchanger.
7. Loosen compression fittings on the bottom of both
return pipes Jabove the shut off valves.
8. Remove the four 13 mm Hex nuts Fand remove heat
exchanger Gfrom the boiler.
9. Remove the Torx screws (T-40) Hat the top of the
heating return pipes Jand remove with O-rings I
and K.
IMPORTANT
Use new gaskets and O-rings on all connections.
10. Replace parts as required and reassemble the heat
exchanger as per steps 9 through 2 respectively and
torque fasteners per legend.
Legend
Tighten the following fasteners on assembly:
A8.9 lb.in. (1 Nm)
D8.9 lb.in. (1 Nm)
J74 lb.ft. (100 Nm)
F 70.8 lb.in. (8 Nm)
H70.8 lb.in. (8 Nm)

5698 072 - 02 Technical information subject to change without notice. Printed on environmentally friendly
(recycled and recyclable) paper.
Heat Exchanger Assembly Installation
WARNING
Gas leaks can lead to explosions. Check the gas pipe
seals to ensure that there are no leaks.
For more details refer to the Installation and
Service Instructions applicable to this boiler.
Refer to the Installation and Service Instructions
to activate air bleed program.
1. Fill the boiler, bleed air and check for leaks.
2. Install burner assembly.
3. Close control unit.
4. Install front enclosure.
5. Place the boiler back in operation.
Air gap
1. Install the condensate drain pipe with a suitable
gradient. Pull the condensate hose so far out of the
boiler that no unnecessary bends are created inside
the boiler. Check tightness of siphon connection.
2. Discharge condensate from the boiler into the
drainage system, either directly or (if required) via
a neutralization unit (accessory).
Installation Instructions of Neutralization Unit
(if applicable)
IMPORTANT
Ensure the condensate drain pipe is pulled down and
positioned to allow the condensate to properly drain.
Reconnecting the Boiler
IMPORTANT
Pipe ventilation must take place between the siphon trap
and the neutralization unit (if applicable).
IMPORTANT
Do not connect the drain pipe from any other appliance,
such as water softener backwash pipe, to Vitodens con-
densate drain pipe.