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Descaling
9
Descaling
Descaling the fresh water module
If the heat exchanger of the fresh water module is
calcified, it can be descaled via the two purging
connections with the use of acetic acid or formic acid.
Fig. 9-1: Purging connections
When descaling using acid, the flow sensor must
be removed and replaced with an adapter as it is
not acid-proof.
Fig. 9-2: Flow sensor
Once a plate heat exchanger has been calcified,
it will never again provide the same level of
performance as a model that is 'as new'. In the event
of heavy calcification, we recommend replacing the
plate heat exchanger. The fair spare part price offered
by ETA means that replacement is often even cheaper
than purging or descaling, both of which are labour-
intensive.
Using acetic acid or formic acid
5 to 12 per cent acetic acid or 10 to 20 per cent formic
acid is suitable for descaling purposes. Both acids are
available from drugstores. Pay attention to the concen-
tration.
CAUTION!
Always pour the acid into the water; never pour the
water into the acid (this leads to spraying that can
cause burns). Use protective gloves and safety
goggles.
In standard cases, use the medium specified dilution.
Dilution using less water poses a risk to the seals.
Mixing ratios:
•
Dilute vinegar essence (25%) with 1 to 4 parts
water
•
Dilute acetic acid concentrate (60%) with 4 to 12
parts water
•
Dilute formic acid (85%) with 4 to 8 parts water
Professional mixtures including phosphoric acid
are available for treating particularly stubborn cal-
cification.
Purge the fresh water module for 1 hour
Mix 10 litres of dilution and use a purging pump to
purge the solution via a pellet bin for approximately
1 hour.
After purging
Having purged the heat exchanger, seal the
connections once more and reattach the cover.
