BWT P-FI 400 - Backwashing; The Filter Pressure Falls below the Pressure Indicated by the Red Needle of the Pressure Gauge

• Filtration run time
The ltration run time is determined by the theoretical time it would take for the total water volume to pass
through the pump. For a family pool, the allowed recycling time is 6 hours min.
We recommend the following run times as a function of water temperature:
• below 14° C: 5 to 6 h per day.
• from 15° to 23° C: 6 to 8 h per day.
• above 23° C: 10 to 12 h per day.
The busier the pool and the higher the water temperature the longer the ltration run times that will be
necessary to ensure clean water. To optimise ltration e󰀩ciency, run the lter during the day only (between
8:00 am and 9:00 pm) and while the pool is in use (one person in the pool pollutes 3 m3 of water). This
recommendation does not apply to above ground pools in which, as a safety measure, ltration should
be stopped while the pool is in use (for this type of pool, programme ltration just after the bathing times).
7. BACKWASHING
Before putting the lter into operation, carry out a backwash to clean the lter medium and remove excess
sand along with any dirt or debris.
Next, switch the valve to Filtration and turn the pump on, The needle on the pressure gauge indicates the
nominal pressure experienced by the lter. This pressure will vary as a function of pump owrate, static
pressure and head loss across the pipes.
To preserve a trace of this nominal pressure, align the red needle of the pressure gauge with the needle
indicating the nominal pressure.
After a time, the owrate at the pool return will drop due to the gradual build up of dirt and debris in the
lter or pump prelter.
7.1 The lter pressure falls below the pressure indicated by the red
needle of the pressure gauge
clean the pump prelter.
• Stop the pump,
• Switch the multiport valve to «CLOSED»,
• Close the suction and return valves,
• Open the prelter and remove the basket,
• Clean using a water jet to remove dirt and debris,
• Replace the basket,
• Replace the prelter lid making sure that the seal is correctly positioned and that there is enough water to
prime the pump,
• Switch the multiport valve to «FILTRATION»,
• Open the suction and return valves,
• Turn the pump on.
This procedure should be carried out after vacuuming the pool and at least once a week.
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2021/01 - Indice de révision : G - Code : 26650FILTRATION