Bosch Singular 4000 Installation Instructions Manual page 51

3. Once the front cover is removed, place it in a safe location to prevent
accidental damage. With the internal components exposed, locate the gas
connector and the gas valve.
Figure 78
4. Loosen the nut connecting the gas connector and the gas valve. Carefully
separate the gas inlet pipe.
Figure 79
5. Once the gas inlet pipe is detached, carefully remove the four screws on the
gas connector by hand using a Phillips screwdriver and pull the gas connector
away from the TDR damper.
6. Once the gas orifi ce is exposed, remove the screw that holds the gas orifi ce in
place and remove the gas orifi ce from its housing.
Singular Combi Boiler - BTC 439003301 B (2021/07)
Gas connector
Gas valve
Figure 80
Figure 81
Packing
7. Replace the old orifi ce piece and the packing with new part for use with LP
gas. Ensure that the orifi ce is properly seated inside the port.
DANGER: FIRE, EXPLOSION
 Inspect the packing whenever they are disassembled. The
packing must be in good condition and must be installed.
Failure to comply will cause a gas leak, resulting in severe
injury or death.
8. Remove two sealing packings from silencer.
Silencer
Installation Instructions
Orifice
Gas connector
Sealing packing
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