Bosch SSB85 Service Manual page 25

[2] Disconnect the air inlet hose from Venturi of fan as shown below;
Air inlet hose
Fig. 63 Air inlet hose SSB85 - SSB120
Fig. 64 Air inlet hose SSB160
[3] Close the manual gas valve upstream to the boiler and then
disconnect the fitting on gas pipe as follows;
Fig. 65 Gas fitting SSB85 - SSB120
SSB
Air inlet hose
Gas fitting
Maintenance schedule & procedures | 25
Fig. 66 Gas fitting SSB160
[4] Remove the fan unscrewing the 4 nuts that fix it to the heat
exchanger (see picture below showing 3 out of 4 nuts);
Fig. 67 Fan - 4 nuts
[5] Remove the fan;
Fig. 68 Fan
Gas fitting
A
Fan
6720866940 (2017/11) US