BWT RTM HF S-500 Montage- Und Bedienungsanleitung Seite 18

5. BACK WASHING THE FILTER
Before using the filter for the first time, carry out a backwash to clean it and remove any excess sand or
impurities.
After back washing the filter, change the valve position to filtration and switch the pump on. The black hand
on the pressure gauge will indicate the filter's nominal pressure. This pressure varies depending on the
pump flow rate, static pressure and pressure drops across the piping. .
To preserve a record of this nominal pressure, turn the dial of the pressure gauge until the blue hand is
aligned with the black one.
After a certain time, a drop in the flow rate may be noted at the return fittings. This is caused by the gradual
build up of impurities in the filter or the filter basket.
5.1 Filter pressure is below the pressure indicated by the blue hand:
clean the filter basket and the skimmers
• Stop the pump,
• Put the 6-way multiport valve to "CLOSED",
• Close the suction valves A, B, C, D (skimmers, main drain) and the return fitting valve E,
• Open the prefilter and take out the basket,
• Using a jet of water remove any debris,
• Put the basket back,
• Replace the lid of the prefilter making sure that the seal is correctly positioned and that there is enough
water to prime the pump,
• Clean out the skimmers.
• Put the 6-way multiport valve to "FILTRATION",
• Open the suction valves A, B, C, D (skimmers, main drain) and the return fitting valve E,
• Restart the pump,
• Purge air from the filter.
• This operation should be carried out each time the pool is vacuumed using a brush on a suction line,
and at least once a week.
5.2 Filter pressure rises out of the green zone: Backwash the filter
• Stop the filter,
• Check the prefilter for debris. (If there is a build-up of dirt clean it out as described above),
• Put the 6-way multiport valve to the "WASH" position,
• Open the 1/4 turn valve (F) on the outflow pipe,
• Turn the motor on,
• Monitor the water colour through the turbidity sight glass on the 6-way multiport valve.
Caution, cleaning will start after a few seconds. (The water becomes very cloudy)
• As soon as the water in the turbidity sight glass becomes clear, stop the pump,
• Put the 6-way multiport valve to the "RINSE" position,
• Turn the pump on for about 20 to 30 seconds. The purpose of this step is to evacuate any remaining
impurities and settle the sand,
• Stop the pump,
18/32
2020/10 - Indice de révision : H - Code : 26680 CONSTRUCTION & RENOVATION