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4. Maintenance
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Flushing:
In order to flush the membrane, only the flushing valve has to be opened. Then, the
water flows with high speed through the narrow channels in the membrane and takes most of the
residuals with it. This flushing also cleans the flushing valve itself.
After 15 - 20 minutes, the valve must be closed again - tear only handtight. If you tighten the
valve too hard, the valve and membrane will be destroyed. A minimum water flow (approx. 12 -
15/ 15 - 18 l/h) has to be guaranteed.
-
Pre-filter:
If the tap water is not extremely polluted, a yearly replacement of both pre-filters will
be sufficient. If the water is higher polluted, the filters have to be changed more often - as
required. If the pre-filter is blocked, the water production will slow down.
-
Membrane:
The membrane has a lifetime of several years. Afterwards, it has to be replaced.
-
Flushing valve:
The flushing valve is a part with limited lifetime. In case of a decrease of
adjusted water flow, the valve is encrusted with calcium and can be cleaned using acid (e.g. acetic
acid). If the water flow increases, the valve has to be replaced.
5. Failures
- Waste water flow rate is too high:
Try to close the flushing valve. If this is not possible, the flushing valve must be replaced and check
the membrane power.
- Waste water flow rate is too low:
Check if the pre-filter is blocked. The water pressure at the pressure gauge behind the pre-filters
must not be much lower (at the most 0.5 bar) than the water supply pressure. Maybe change the
pre-filter.
- Pure water flow rate is too low:
Check the waste water flow rate. If it is to low too, change the pre-filter.
- Tap water pressure is too low:
If you are connected to a municipal water supply, you are not able to have an influence on the
water pressure. For the reverse osmosis unit, a minimum water pressure of 3 bar is required.
- Module is blocked or used up:
The membrane has to be replaced.
As spare parts, all standard „18“ membranes with a daily capacity of 75 - 90 / 120 - 150 l can be
used. Only TFC-membranes made of Polyamide/Polysulfone should be used. We recommend to use
original AB Aqua Medic TFC-membranes only. If you want to use a membrane with a different
capacity, you have to change also the flushing valve.
- Rejection rate is too low:
Check the water flow rates (waste water, pure water).
If the water flow is ok, flush the unit for approx. 60 min. If the rejection rate increases, go on
flushing until the value is acceptable. If the rate does not improve, change membrane.
6. Important Notes
- Connection:
Connect the reverse osmosis unit to cold water supply only. Higher temperatures
increase pure water production but at temperatures more than 40 °C, the membrane will be
destroyed.
