12
Gas type conversion
DANGER: Personal injury and property damage
▶ This conversion shall only be performed by a trained
and certified installer in accordance with the
manufacturer's instructions and all applicable codes
and requirements of the authority having jurisdiction.
▶ If the information in these instructions is not followed
exactly, or the installation, adjustment, modification,
operation or maintenance is carried out by an
unqualified person, a fire, explosion or generation of
large amounts of carbon monoxide may result causing
property damage, personal injury or loss of life.
▶ Before carrying out electrical work: Disconnect the
installation from the power supply at the emergency
shutoff switch or by disengaging the heating system
circuit breaker. Take measures to prevent accidental
reconnection.
▶ The installer is responsible for the proper conversion
of this appliance.
▶ The conversion is not complete until the operation of
the converted appliance is checked as specified in
these instructions.
The gas-air ratio must always be set on the basis of a CO
reading taken at maximum nominal output and minimum nominal
output using an electronic flue gas analyzer.
Adjustment to different flue systems using throttle discs or baffles is not
necessary.
NG
• Appliances are set at the factory to Wobbe index 1,333 BTU/ft
3
(49.6 MJ/m
) at 60 °F (15 °C), 30" Hg (1016 hPa) and 7.0" W.C.
(17.4 mbar) gas supply pressure and sealed.
12.1 Converting to a different gas type
DANGER: Explosion!
▶ Close the gas cock prior to working on the gas train.
▶ Check for gas leaks after carrying out work on the gas
train.
A gas conversion kit is included in the scope of delivery.
▶ Fold the Heatronic down.
▶ Check the number on the code plug from the gas conversion kit (Code
plug number table 43, page 80).
Greenstar
▶ Replace the code plug in the Heatronic with the code plug from the gas
conversion kit.
Fig. 75 Replacing the code plug
▶ Affix the gas type label from the gas conversion kit to the appliance.
or O
2
2
3
Fig. 76 Affixing the gas type label
▶ Always adjust the gas-air ratio (CO
Section 12.3) after converting to a different gas type and measure
the CO content of the flue gas ( Section 13).
12.2 Installation location higher than 2,000 feet (610 m)
above sea level
Input and output rates are reduced at higher altitudes due to thin air with
reduced oxygen levels.
ZBR42-3A... and ZWB42-3A... appliances are derated at 3 % per
1000 feet (305 m).
ZBR16-3A..., ZBR21-3A..., ZBR28-3A..., ZBR35-3A..., ZWB28-3A...
and ZWB35-3A appliances offer altitude adjustment which
compensates for the effects of thin air, and are therefore NOT derated
up to 6000 feet (1829 m). Above 6000 feet (1829 m) a rate of 3 % per
1000 feet (305 m) applies.
The Bosch Greenstar boiler is factory set for installation
below 2000 feet (610 m) above sea level.
▶ Correction of the fan speed curve of the burner:
Use service function 0.d to adjust the elevation setting ( page 63).
Gas type conversion | 65
6 720 641 933-57.1O
6 720 641 933-58.2O
or O
,
2
2
6 720 806 992 (2015/03)