Why Does My Tank-Based RO System Sometimes Start and Sometimes Stay Off?

All OJA reverse osmosis systems use pressure sensors that detect the presence of water at the system inlet to prevent the pump from running dry, and monitor RO water pressure to prevent continuous water discharge when the faucet is closed and the tank is full.

With a direct-flow (tankless) RO system, the RO water pressure reading is binary: either the faucet is open and the pressure is low, or the faucet is closed and the pressure is high. The result is therefore very easy for the pressure sensor to interpret.

However, if you have a tank-based RO system, things work differently. Every time you use RO water, the tank pressure drops slightly. Either it falls below the sensor's threshold and the pump starts to refill your tank, or it stays above the threshold and nothing happens.

Another consequence is that the RO system's running time, and therefore the amount of drain water, may seem high compared to the amount of RO water used at that particular moment. However, your calculation must also account for the total amount of RO water used previously without the system starting.

Here is a quick example… I draw 10 cl of RO water from my Classicos to make a coffee at 8 a.m., then another at 10 a.m. At noon, I pour myself a 20 cl glass of water, and my RO system starts. It then produces 40 cl of RO water and discharges 80 cl into the drain.

The ratio is therefore indeed 2:1, rather than 4:1 as you might think if you compare the 80 cl discharged with the 20 cl in my glass of water.

If you have any other questions about RO systems, feel free to call us at 09.72.55.18.50 or send an email to contact@josmose.fr.

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