Bosch Appliances 250SX NG Water Heater User Manual


 
6 720 607 057
32
Special adjustment for measuring and adjusting CO2 levels
9 Special adjustment for measuring and adjusting CO
2
levels
The CO
2
can only be adjusted by a certified gas
technician with a calibrated CO
2
analyzer.
9.1 Adjusting the unit
Factory settings of this appliance are listed in table 7.
Further adjustment is only needed if optimal CO
2
level
is required in order to assure the minimum possible
CO
2
emissions. In this case a CO
2
analyzer is required.
9.1.1 CO
2
measuring
B Loosen screw 1 (Fig. 41).
B Insert CO
2
analyzer into measuring port (Fig. 41,
pos. 1).
Fig. 41
1 Measuring point
9.1.2 Selecting adjustment mode
B ON/OFF switch in position OFF (0).
CO
2
adjustment at minimum gas flow (P2) - See
table 7.
B Press “Program” key and turn ON/OFF switch to
position ON.
Fig. 42
LCD shows “P2” and the appliance is ready to be
adjusted.
B Open hot water tap.
The appliance will run constantly at minimum power
output and minimum water flow. This program step can
also be used to measure minimum output and minimum
water flow.
B Turn the screw in order to regulate the air-gas mixture
inside the ventilator until the CO
2
level required is
reached (Fig. 43, pos. 3).
CO
2
adjustment at maximum gas flow (P1) - See
table 7.
B Press , until “P1” appears.
B Open hot water tap.
The appliance will run constantly at maximum power
output and maximum water flow. This program step can
also be used to measure maximum output and maximum
water flow.
B Turn the screw in order to regulate the air-gas mixture
inside the ventilator until the CO
2
level required is
reached (Fig. 43, pos. 3).
Caution: Converting the gas type can
only be done by a certified gas
technician with a calibrated CO
2
analyzer. Call CEC for conversion
instructions.
Caution: Adjustments must only be
carried out by authorized service
personnel only.
Caution: The appliance should always
be disconnected from the power supply
before any maintenance is carried out.
Factory
setting
Field settings
acceptable range
Nat. Gas Nat. Gas
max. input P1 9.50 % 8.00 % to 10.00 %
min. input P2 9.50 % 8.00 % to 10.00 %
LP Gas LP Gas
max. input P1 10.50 % 10.00 % to 11.00 %
min. input P2 10.50 % 10.00 % to 11.00 %
* Final reading must be confirmed with the front cover
on, CO
2
levels increase when the cover is installed.
Table 7