Maintenance Activities For Technicians - Bosch DOMESTIC HOT WATER HEAT PUMP Technical Manual

pH
o
calcium content
o
alkalinity
o
ionic strength of the water (Is)
o
Please note:
- For water analysis, mg/l is equivalent to ppm
- The relation between calcium and calcium carbonate is 40g CA
- TDS = salt content (mg/l) or possibly the conductivity x 0.63 (μS/cm)
If Is<0, the water has a tendency to be corrosive.
If Is>0, the water has a tendency to cause scaling.
Eliminating the scaling problems
There are several ways to eliminate the scaling problem. Usually a commercial product containing additives to
enhance the effect and / or prevent corrosion can be used; nevertheless a specialist should be consulted to
recommend the adequate procedure for the treatment. Chemical cleaning is the use of chemicals to dissolve or
loosen deposits from process equipment and piping. Removal is uniform and generally at a low cost.
Step 1: Chemical cleaning solutions
Using organic acids (are weaker than mineral acids but safer to material and handling). The organic acids can be
used in combination with other chemicals to remove the scale completely.
Acetic acid is used to clean calcium carbonate scale.
Step 2: Passivation
Passivation is a procedure to remove surface iron contamination from the equipments.

6.4 Maintenance activities for technicians

In terms of maintenance, it is strongly recommended a general control of the main components of the heat pump,
before the control of the refrigerant module circuit.
Component
Magnesium anode
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6720649497 SM HP270-1 2012/09 en
2+
≃ 100g CaCO
3
Action
1)
Electric measurement or visual inspection
1)
Depending on the version