Backwashing; The Filter Pressure Falls Below The Pressure Indicated By The Red Needle Of The Pressure Gauge - BWT P-FI 400 Notice D'installation Et Conseils D'utilisation

• Filtration run time
The filtration 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 filtration run times that will be
necessary to ensure clean water. To optimise filtration efficiency, run the filter 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, filtration should
be stopped while the pool is in use (for this type of pool, programme filtration just after the bathing times).
7.

BACKWASHING

Before putting the filter into operation, carry out a backwash to clean the filter 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 filter. This pressure will vary as a function of pump flowrate, 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 flowrate at the pool return will drop due to the gradual build up of dirt and debris in the
filter or pump prefilter.
7.1 The filter pressure falls below the pressure indicated by the red
needle of the pressure gauge
clean the pump prefilter.
• Stop the pump,
• Switch the multiport valve to «CLOSED»,
• Close the suction and return valves,
• Open the prefilter and remove the basket,
• Clean using a water jet to remove dirt and debris,
• Replace the basket,
• Replace the prefilter 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.
FILTRATION 2021/01 - Indice de révision : G - Code : 26650
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