15.0
Changing Components
46
© Baxi Heating UK Ltd 2014
15.1
Changing Components
IMPORTANT: When changing components ensure
that both the gas and electrical supplies to the boiler
are isolated before any work is started.
“The boiler cannot be switched off at the boiler,
therefore it is important to isolate the electrical
supply at the mains fuse.”
Hazardous materials are not used in the construction
of these products, however reasonable care during
service is recommended.
When replacing the combustion box door after
changing components, it is essential that the retaining
screws are tightened fully.
After Changing Components a combustion check
should be performed (see Section 15.8.11). This is
especially important on gas carrying parts, and those
that may affect combustion (e.g. fan).
1. Before changing any components please read Section
1.2 Important Information.
2. Remove the outer case and lower door panel (see
“Fitting the Outercase” Section 13.0).
WARNING: The PCB Control and Fan
Assembly are 325 Vdc. Isolate at supply
before access.
3. Isolate the water circuit and drain the system as
necessary. A drain point is located on the heat
exchanger manifold at the right hand side of the boiler
(Fig. 45) to enable the heat exchanger to be drained.
4. Place a tube on the drain point to drain water away
from electrics. Turn anticlockwise to open (Fig. 45).
NOTE: When reassembling always fit new ‘O’ rings,
ensuring their correct location on the spigot. Green
“O” rings are used for gas joints and Black “O” rings
for water joints. Use Greasil 4000 (Approved
Silicone Grease).
5. After changing a component re-commission the
boiler where appropriate and check the inhibitor
concentration (see Section 6.2 and 12.1).
The thermistor, safety thermostat, interface PCB and
the flow switch can be accessed after removal of the
outer case.
15.2
Flow Temperature Thermistor and
Safety Thermostat
(Fig. 46)
1. The procedure is the same for both the thermistor
and the safety thermostat.
2. Remove the electrical connections from the sensor.
3. Unscrew the sensor from the pipe.
4. Fit the new thermistor or safety thermostat and
reassemble in reverse order.
Drain Point
Heat Exchanger
Manifold
Tube
Electrical Connections
Flow Temperature Thermistor
Safety
Thermostat
Fig. 45
Fig. 46
