Virtually all WC urinals in the UK operate using an automatic syphonic cistern.
This means that they flush each time the cistern fills, often more than three times an hour, even when your building is unoccupied at night or closed for holidays.
Most of this expensive water goes to waste.
The Marnic Water Watch system detects when the facility has been used.
A PIR (Passive Infra-Red) sensor detects individuals using the urinals and triggers the filling of the cistern.
The urinal then flushes in the normal way.
The system comprises of a simple retrofit kit that can be installed to existing urinal toilets in 30-40 minutes or can be used in the construction of new urinal facilities conforming to the latest building regulations. It consists of a water-control valve fitted to the water inlet pipe prior to the petcock. This valve is electrically operated by the Water Watch PIR sensor.
The Water Watch can be programmed during installation to provide optimum flushing during periods of toilet use. The default setting is 20 minutes but other flush cycle lengths of 15, 30 or 60 minutes can be also selected.
In addition to the normal flush setting, a 12- or 24-hour delay between detection and flushing can be selected to ensure that the urinal is flushed at least once or twice a day. This way the hygiene flush keeps the urinals clean and fresh even when the toilet is unoccupied.
Step 1:
Turn off the water supply.
Step 2:
Cut the pipe and flush it out with water. Fit the valve, leaving the petcock in place.
Step 3:
Select a position for the Water Watch near the urinals where it will detect use.
This can be either on the wall or the ceiling, a minimum of 12 cms away from the edge to allow space for the use of a standard screwdriver.
Attach the base plate to the wall or ceiling.
The control box hooks under the bottom edge of the backplate and is held in place by raising the head of the internal screw.
Step 4:
Cable between the valve connector and the Water Watch
Note that the valve actuator can be positioned either up or down
Inside the Water Watch leave a small loop of cable as slack so that the lid can be detached from the mounting plate.
Alternatively remove the blanking plug from the top of the Water Watch and feed the cable through the top cable gland.
Step 5:
Start with the cistern empty. Inside the Water Watch, the valve switch should be in the ‘CLOSED’ position.
Open the valve. The lamp will flash on detection. Inside the Water Watch, the valve switch should be in the ‘OPEN’ position.
When the flush starts, wait a few seconds for the flush to establish. Then close the valve. (Inside the Water Watch, the valve switch should be in the ‘CLOSED’ position.)
The time taken for the cistern to fill during set-up is stored and used for all subsequent automatic flushes.
Water Watch is now fully operational!
Close the lid.
If the lamp is flashing, check that the valve switch is in the correct ‘CLOSED’ position. The valve switch must never be left in the ‘OPEN’ position.
The lamp will now only operate when the battery needs changing.
For instructions on how to change the flush settings, see the Maintenance section below.
Cleaning the control unit:
The control unit may periodically be wiped with a damp cloth and mild detergent.
As with all electronic/electrical devices, it should not be sprayed with water or steam-cleaned.
Cleaning the valve:
The control valve should be cleaned periodically together with any associated dirt collector or filters, if fitted. It is generally not necessary to remove the valve from the pipe.
The valve can be cleaned in 5 easy steps:
Step 1:
Remove the valve coil by slipping the plastic split washer off
Step 2: The valve actuating can then be removed and the two raised screws can be removed.
Step 3: It is then possible to separate the two parts of the valve, taking care not to lose the two rubber ‘O’ ring water seals.
This may be carefully removed and flushed with clean water to remove any accumulated debris. Flush clean water through and solenoid body to clean thoroughly.
Step 4: Reassemble the valve and valve actuator carefully.
The valve can be tested by operating the circuit board and switch.
Step 5: The switch must be returned to the closed position within one minute, otherwise the flush fill time will be affected.
Changing the battery:
It is recommended that the battery be replaced every three years. Under normal operating conditions the red lamp on the control box will flash when the battery requires changing and each battery is stamped with a replacement date which should not be exceeded.
The controller cover is removed from the back mounting plate by inserting a screwdriver into the hole on the controller top edge and screwing down the retaining screw. the electronics and battery are contained in the controller cover and care must be taken not to disturb the interconnecting cable.
Remove the old battery which is retained by a velcro pad. New batteries are available from your supplier or Marnic Technology (see the Contact section).
Install the replacement battery and follow the standard set-up procedure (see the installation section for further details) before replacing the control unit cover.
Changing the flush settings:
See the ‘How it Works’ section for instructions on how to change the flush rate.
Operational testing:
The 3 checks listed below can be carried out at any time during the lifetime of the product.
To carry out these checks access is required to the inside of the Water Watch controller.
1. Check that the valve is operating:
Slide the switch at the top right-hand corner of the circuit board down to the “OPEN” position. -> The valve should open.
If the valve does not operate but Check 2 (the movement sensor test) gives a positive result, clean the valve filter (for more instructions on how to do this, click the ‘Cleaning the Valve’ section above).
If this does not restore the valve, try a replacement valve.
2. Check the movement sensor:
Carry out the valve est described in Check 1.
While the switch is in the “OPEN” position the red lamp on the front panel should flash intermittently in response to movement.
If the lamp does not flash but the valve operates, replace the circuit board.
If the lamp does not flash and the valve also fails to operate, change the battery.
3. Check the battery:
If the red lamp is flashing and the switch is in the (normal) “CLOSED” position, replace the battery.
If you have a volt meter, the battery voltage should be above 5 Volts.
If a volt meter is not available, a confidence check can be carried out by conducting the valve test described in Check 1.
Sensor Unit:
Dimensions: 125x80x35mm
Construction: Vandal-resistant steel enclosure
Finish: Wipe-clean, white enamel
Programmable flush-rates
Maximum rates: 4 flushes/hour
3 flushes/hour
2 flushes/hour
1 flushes/hour
Hygiene cycle: 12 or 24 hours selectable
Time measurement: Quartz crystal clock
Movement detector:
Type: PIR (Passive Infra-Red)
Range (max.): 5 metres
Lens: Multi-zone LED
Indicator: Flashing red LED (walk test during commissioning)
Water Supply Valve:
Solenoid valve: 9V latchng; WRAS approved
Operating pressure: 0.1-10 bar, fast fill
Lens: Multi-zone Fresnel
Integral water filter: Stainless filter; replaceable
Battery Power Supply:
Battery: 4.5V, 5.4AHr, Duracell
Battery low indicator: Flashing red LED
Battery life: 4-7 years
Mains Power Supply (Option):
Voltage: 240V AC, 50Hz
Power consumption: 1.8 Watts
Connection: 1A unswitched fuse sput
Water Audit:
Interface: 300Bits/s serial data
Audit Data:
Flush settings, Total flushes, Hygiene flushes, Fill-time, Valve open time, Operating hours, Battery voltage