Thermal Disinfection; Inspection And Maintenance; Safety Instructions For Inspection And Maintenance; Safety-Relevant Components - Bosch Condens 8300i W Installation And Maintenance Instructions Manual

Inspection and maintenance

8.3

Thermal disinfection

To prevent hot water from becoming contaminated by bacteria such as
legionella, we recommend thermal disinfection after long downtimes.
You can program a heating controller with hot water control to perform
thermal disinfection. Alternately, you can have a contractor carry out
thermal disinfection.
CAUTION
Risk of scalding.
During thermal disinfection, discharging unmixed hot water can cause
serious scalding.
▶ Only use the maximum adjustable hot water temperature for thermal
disinfection.
▶ Inform occupants of the premises of the risk of scalding.
▶ Perform thermal disinfection outside of the normal operating times.
▶ Do not discharge DHW unmixed.
Proper thermal disinfection involves the DHW system including the
draw-off points.
▶ Set the thermal disinfection in the hot water program of the heating
controller ( heating controller operating instructions).
▶ Close DHW draw-off points.
▶ Enable continuous operation of any DHW circulation pump that may
be installed.
▶ Once the maximum temperature is reached, open the DHW draw-off
points one by one, starting from the nearest and ending in the
farthest, and draw off DHW until hot water at 70 °C has been
discharging for 3 minutes.
▶ Restore the original settings.
9 Inspection and maintenance
9.1

Safety instructions for inspection and maintenance

HNotes for the target group
Only approved contractors may carry out inspection, cleaning and
maintenance in compliance with the system-relevant instructions.
Improper execution may result in personal injury, including danger to life
or material damage.
▶ Inform the user of the possible consequences of non-existent or
improper inspection, cleaning and maintenance.
▶ Inspect the heating system at least once a year.
▶ Carry out any required cleaning or maintenance work according to
the checklist ( page 37).
▶ Remedy all defects immediately.
▶ Check the heat exchanger assembly once a year, and if necessary
clean it.
▶ Use only original spare parts.
▶ Observe the service life of gaskets.
▶ Replace removed gaskets and O-rings with new ones.
▶ Record any work carried out.
HDanger to life through electric shock!
Touching live parts can result in an electric shock.
▶ Before carrying out work on electrical components, isolate them from
the power supply (230 V AC) and secure against unintentional
reconnection.
HRisk of death from escaping flue gas!
Escaping flue gas can cause poisoning.
▶ Check for leaks after working on flue gas-carrying components.
36
HRisk of explosion from escaping gas!
Escaping gas can cause an explosion.
▶ Close the gas isolator prior to working on gas-carrying components.
▶ Carry out tightness test.
HRisk of scalding from hot water!
Hot water can lead to severe scalding.
▶ Make residents aware of the risk of scalding prior to activating the
chimney sweep mode or a thermal disinfection.
▶ Carry out thermal disinfection outside the normal hours of use.
▶ Do not change the maximum domestic hot water temperature set.
HRisk of burning from hot surfaces!
Individual components of the floor standing boiler can become very hot
even after being shut down for a long time!
▶ Before working on the boiler: allow the device to cool down.
▶ If necessary, wear protective gloves.
HEscaping water can damage the device.
The control device can be damaged by escaping water.
▶ Cover the control device prior to work on parts routing water.
HObserve the tightening torque.
Table 22 Standard tightening torque
Notification must be provided of all deviations in tightening torque.
9.2

Safety-relevant components

Safety-relevant components (e.g. air/gas ratio control valves) have a
limited service life, which depends on their operating time in switching
cycles or years.
If the operating time is exceeded or due to increased wear, the affected
component may fail and the system safety may be lost.
▶ Do not repair, manipulate or disable safety-relevant components.
▶ Check safety-relevant components during every inspection and
maintenance to determine the continued safety of the system.
▶ Replace safety-relevant components in the event of increased wear
or at the latest when they have reached the end of their service life.
▶ Only use new and undamaged original spare parts for replacement.
Component Max. operating time
in switching cycles
Air/gas ratio control 500.000
valve
Table 23 Operating time of safety-relevant components
9.3

Resources for inspection and maintenance

• The following measuring devices are required:
– Electronic flue gas analyser for CO
temperature
– Pressure gauge 0 - 30 mbar (minimum resolution 0.1 mbar)
▶ Use heat conducting paste 8 719 918 658 0.
▶ Use approved greases.
Condens 8300i W – 6721841531 (2022/10)
G 1/2" Nm 20 (+10/‒0)
G 3/4" Nm 30 (+10/‒0)
G 1" Nm 40 (+20/‒0)
Max. operating time
in years
10
, O , CO and flue gas
2 2