BWT bestaqua ROC ULTRA

Our ROC systems use a T1.25A fuse. If the fuse blows repeatedly, the issue may be:

1. A short circuit (on PCB or in 230 V wiring)
2. A defective capacitor
3. A faulty pump or coupling, making it difficult for the rotor to spin, causing increased power consumption

In general, we do not specify fixed membrane capacity, as it depends on individual water quality. Aside from hardness, parameters like Fe, Mn, and SDI (found in section 2.2 of the ROC EBA) should also be considered.

We recommend pretreatment of feed water:

“If total hardness exceeds 10 °dH or if the ratio of temporary to total hardness is more than 80%, pretreatment is necessary to ensure product reliability and performance.” This statement is included in section 2.2 of the ROC EBA (Operating Conditions) and applies to all RO products.

Note: This is a recommendation – the membrane can technically handle harder water but may require more frequent replacement.

Our ROC systems have been developed and tested according to:

• EMC Directive 2014/30/EU
• Low Voltage Directive 2014/35/EU
• RoHS Directive 2011/65/EU

Harmonized standards:

• IEC 61000-3-2:2018
• IEC 61000-3-3:13/AMD1:2017
• IEC 61000-6-1:2016
• IEC 61000-6-3:2020

A valid EU Declaration of Conformity and CB Certificate are available.

Yes. For hotels, large kitchens, or big restaurants, we offer:

• Hydropneumatic tanks from 500 to over 2,000 liters
• Systems often include:
  • Booster pumps
  • Automatic refill controllers
  • Pressure switches

This creates a fully automated, high-pressure purified water system - ideal for industrial-level demand.

Our filters are tested on a random sample basis. This includes a pressure test (with increasing pressure levels) and an additional burst test to ensure durability and safety.

A pressure tank contains:

• One chamber for purified water
• One chamber for compressed air, separated by a diaphragm or bladder

As water fills the tank:

• The air compresses
• This compression creates water pressure when an outlet is opened
• Once the pressure drops to a certain level, the RO system restarts to refill the tank

Think of it as a spring-loaded water reserve, ensuring instant availability.

Yes. Every BWT filter head contains an integrated check valve. Backsiphoning is not possible. Non-return valves are installed at both inlet and outlet by default.

A single RO system may feed:

• Beverage stations (coffee, tea)
• Ice makers
• Food prep sinks
• Dishwashers
• Refill water stations

A pressure tank:

• Acts as a central hub with pressurized RO water
• Prevents pressure and flow drops, even during simultaneous usage

An organic smell can occur after prolonged downtime. This usually disappears after a few minutes of flushing. As mentioned in section 6.3 of the EBA:

"If the system has been out of operation and disconnected from power for an extended period (e.g., during vacation), a 10-minute flush is required before reuse. Make sure the rinse water can drain freely. The flushed water should be discarded."

A few years ago, membranes were commonly preserved wet in a 1% sodium thiosulfate solution to maintain performance and prevent microbial contamination.

Today, most suppliers – including us – deliver membranes in a dry state, which is easier to handle and ensures a longer shelf life. Preservation only applies to new membranes. Once a membrane has been used, preservation chemicals cannot be re-applied.

Yes. In HORECA settings, short peak windows may require 50–100 liters in 30 minutes. A standalone RO system cannot deliver this immediately.

A pressure tank with 200–500 liters capacity ensures sufficient reserve during high-demand periods.

Yes. In case of:

• Power outages
• Pump failures
• Low feed water pressure

…the pressure tank maintains temporary business continuity. It ensures critical functions can continue without interruption for a short period.

RO systems filter water slowly, molecule by molecule.

For example, BWT bestaqua ROC systems produce around 2.0 to 3.0 liters per minute. Without a buffer (i.e. a tank), the system cannot meet sudden spikes in demand - like during a busy restaurant service.

Without a pressure tank:

• Every small water demand immediately triggers the RO pump
• This causes frequent pump cycling, reducing the lifespan of:
  • Pumps
  • Solenoid valves
  • Non-return valves

A pressure tank absorbs small demands, reducing stress and extending component life.

Store the membrane and filter cartridges in a cool, dry place. Avoid direct sunlight and heat sources (such as radiators, ovens, or sunlit windowsills). A room temperature below 25 °C is ideal.

We are currently working on a suitable solution for RO system disinfection. Further information will follow as soon as it becomes available.

No. RO systems output purified water at low pressure, typically just slightly above atmospheric pressure. However, many appliances (e.g. espresso machines, combi ovens, ice makers) require a minimum inlet pressure, often between 1.5 and 3 bar.

A pressure tank stores RO water under compressed air, delivering it with immediate usable pressure.

Our ROC products undergo a complete End-of-Line functional test. Each individual unit is connected to a testing station and fully tested.

Production at BWT Dynamics is certified according to ISO 9001.

This message may appear when the pump pressure drops below 6 bar. Possible causes include:

1. Defective pump head
2. Low or fluctuating inlet pressure
3. Membrane with higher flow rate
4. Clogged pre-filter
5. Bypass valve on membrane head is open
6. Warm water temperature – this may occur seasonally, especially after winter when water warms up