Adjustments (Must Be Carried Out Only By Qualified Technicians); Factory Regulations; Pressure Adjustment - Bosch WR11B series Installation Manual And Operating Instructions

16 | Adjustments (must be carried out only by qualified technicians)

6 Adjustments (must be carried out only by qualified technicians)
6.1

Factory regulations

Sealed parts must not be interfered with.
Natural gas
Heaters designed for Natural gas H (G 20) are factory
sealed for delivery after the values on the characteristics
panel have been checked.
Heaters should not be ignited when the
connections pressure is less than 1,7 kPa
more than 2,5 kPa.
Liquid gas
Propane/butane heaters (G31/G30) are factory sealed
for delivery after the values on the characteristics panel
have been checked.
Heaters should not be ignited when the
connections pressure is:
- Propane: less than 2,5 kPa more than 4,5
kPa.
- Butane: less than 2,0 mbar more than 3,5
kPa.
Power may be tuned according to the burner pressure
process, for which a manometer with U-shaped
connecting tubes is required.
6.2

Pressure adjustment

Accessing the adjusting screw
B Remove the front part of the heater (see 5.3).
Connecting the pressure gauge
B Unscrew the shut-off screw.
6 720 648 592 (2011/06)
B Connect the pressure gauge to the measuring point
for the burner pressure.
Fig. 14 Pressure measurement points
Maximum gas flow adjustment
B Remove the screw seal ( Fig. 15).
B Turn on the heater with the power selector set to the
left (maximum position).
Fig. 15 Maximum gas flow adjusting screw
B Open various hot water taps.
B Using the adjusting screw, regulate the pressure until
obtaining the values indicated in the table 8.
B Seal the adjusting screw once again.
Minimum gas flow adjustment
The minimum gas flow adjustment is
performed automatically after the
adjustment of the maximum gas flow.
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