Bosch SSB120, Service Manual

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SSB 6720866940 (2017/11) US
Commisioning | 21
7 Commisioning
7 .1 First operation
Before commissioning the boiler the following steps must be verified:
[1] Verify the gas type and pressure match the boiler name plate rating.
When converting the boiler to operate on LP, the LP conversion
sticker or decal must be applied. When operating with NG the
min. gas pressure should be 3.5” w.c. (8,72 mbar), while max. gas
pressure 10,5” w.c. (26.15 mbar). For LP the min. and max. gas
pressures are 8” w.c. (19.9 mbar) and 13” w.c. (32,3 mbar);
[2] Open the manual gas valve
[3] Check water circuit is clean and a water filter on return line;
[4] Verify all shut-off valves are open;
[5] Verify the water fill pressure is correct,
[6] Verify that the intake and exhaust pipes are free from obstruction;
[7] If necessary bleed the gas supply line of air by using the supply
pressure port (“P IN”) see Fig. 46 - Fig. 47;
P_IN P_OUT B A
Fig. 46 Gas supply line SSB85 - SSB120
P_IN P_OUT B A
Fig. 47 Gas supply line SSB160
[8] Verify all electrical connections are correct;
[9] Verify no electrical components were removed or tampered with;
[10] Fill the condensate trap with water and ensure a continuous
downward slope exists in the outlet tube.
Only after verifying steps 1 to 10 should commissioning of the boiler be
performed.
7 .2 Inlet Gas Pressure
It is necessary to check the gas pressure at the inlet of the gas valve
remains steady. With the burner operating the inlet gas pressure should
not decrease more that 2” W.C., if a large fluctuation is detected a
regulator must be used to stabilize the supply pressure.
7 .3 Switching from NG to LPG
The unit comes from factory set for Natural Gas. The unit can be
converted to LPG using the conversion kit supplied by the factory.
a a
WARNING: Conversion of the unit must be performed by a
authorized service technician.
Preliminary Operation
The electrical supply to the boiler must be turned off and the gas supply
must be disconnected from the boiler.
Boiler Model SSB85 - SSB120
The picture below shows the fasteners to access the installation location
for the LPG orifice.
Disconnect the union fitting and insert the LPG orifice and gaskets.
Gas fitting
Fig. 48 Gas fitting - model SSB85 - SSB120
Fastener to be removed
Fig. 49 Installation location for the LPG orifice - model SSB85 - SSB120