Under the BS9251:2021 it is now compulsory to monitor certain aspects of the sprinkler system for its correct state.


FloWatch 9251 makes that really simple.

When selecting mechanical equipment to install, you will now need to use a monitored version, especially isolation valves. You are able to retrofit monitoring switches on existing systems, which allows for system upgrades.

FloWatch 9251 will connect to these system components via a supervised circuit. A supervised circuit contains resisters installed at the end of the cable, at the point it connects to the device. This ensures that the system not only monitors for activations, but also faults that may appear.

If you are combining a FloWatch 9251 monitoring system with our partner Rapidrops monitored product range, the resister installation is already taken care of, eliminating what can sometimes be a troublesome task in small devices.

A fully monitored system will raise an alarm in the event any isolation valve is not in the fully open position, there is insufficient stored water or the pump has a fault which could prevent it from working.

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How Do you monitor a Sprinkler System?


  • Isolation valves

  • Flow switches

  • Tank level switches

  • Booster set fault

FlowWatch Fire Sprinkler Monitoring & Alarm Systems To BS9251

The FloWatch 9251 Master Panel is installed at the entrance to the building or block. Every system requires a master panel. This panel, as a standalone unit, can monitor upto 4 inputs, either monitored isolation valves or flow switches, a tank level switch and a Normally Open Contact from a Booster Set fault output.


For sprinkler systems with more than 4 monitored isolation valves or flow switches, expansion units are connected to the Master Panel allowing additional inputs to be monitored. 


Expansion units are available in an 8 way module. Which can monitor up to an additional 8 inputs. Up to 16 Expansion Devices can be connected to a single Master Unit giving a total of 132 inputs from a single system.

"Monitoring is the Continuous Supervision of the Main Functions of the system whose impairment may effect the correct operation of the system"

A typical installation of a FloWatch Monitoring System is shown in the diagram below. The Master Unit is installed at the entrance to the building and then expansion units are installed in locations in the Sprinkler Riser Cupboard as indicated. The Master Unit can be connected to the first four inputs, then expansion units added to pick up additional inputs upto a total of 132 inputs.

The Master Unit is connected to the first Expansion Unit by a 4 core FP200 1.5mm2 cable, then from the first expansion to the second creating a daisy chained network. 

From the Master Unit or an Expansion Unit, a 2 core FP200 1.5mm2 cable is connected to either the monitored isolation valve or flow switch. The 8 way Expansion module has 8 inputs. One input is either a monitored isolation valve Flow Switch or any another required device.