Bosch GWI-N Series Training And Service Information page 52

Take care not to damage the seals that ensure tightness between the heat exchanger, the
heat cell and collector and ensure correct clearing and alignment of the fins.
In hard water regions it may be necessary to descale the heat exchanger body, using a
proper descaler. Fill the heat exchanger with the descaling solution and let it act until the
solution stops bubbling. Drain and thoroughly wash out the exchanger with clean water.
Warning: Acid/water solutions must be used with extreme caution. Take care not to
splash on to the skin or into the eyes. Wash any affected areas with large amounts of cold
water and seek medical advice.
Pict.53 – heat exchanger descaling
Re-assemble the heat exchanger ensuring its correct position on the two support hooks in
the appliance back plate, good conditions of sealings and tightness between heat
exchanger, collector and burner.
Replacement of Parts
Any service work must be carried out by a competent person such as the technician
indicated by the after sales organization. Before any service operation, turn off the gas
supply at the main gas service cock.
When replacing components, always use the supplied gaskets / sealings.
Page 52 from 76 6 720 814 719 SM FP_Australia 2017/04 EN