Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
5 Installation
83309302 1/2018-05 La
37-196
5.1.3 Treat the fill and top-up water
De-ionisation (recommended by Weishaupt)
De-ionise the fill and top-up water completely.
(Recommendation: mixed bed procedure)
When the heating water has been entirely de-ionised, additional top-up water up to
10 % of the system contents may be untreated. Higher quantities of top-up water
must be de-ionised.
Check the pH value (8.5 ±0.5) of the de-ionised water:
after the commissioning,
after approx. 4 weeks of operation,
during the annual servicing.
If necessary, increase thepH value of the heating water by the addition of Triso-
dium Phosphate.
Softening (cation exchanger)
CAUTION
Damage to the appliance due to raised pH value
Softening the water by means of cation exchange leads to self alkalisation of the
heating water. Corrosion can damage the appliance.
Following the softening of the water by means of cation exchanger the pH value
has to be stabilised.
Soften the fill and top-up water.
Stabilise the pH value.
Check pH value of (8.5 ±0.5) during the annual servicing.
Stabilisation of hardness
CAUTION
Damage to the appliance due to inappropriate inhibitors
Corrosion and scale could damage the appliance.
Only use inhibitors when the manufacturer can guarantee the following:
the requirements relating to the heating water are fulfilled,
the heat exchanger in the appliance will not be attacked by corrosion,
there will be no formation of sludge in the heating system.
Treat the fill and top-up water with inhibitors.
Check the pH value (8.5 ± 0.5) according to the instructions provided by the
manufacturer of the inhibitors.