How to choose a flush valve
Valve or complete kit
The DVS Flush Valve is the KWC DVS WC01 valve alone and needs a KWC DVS control box, so ask us if you have none. The cistern kits add the control box and a sensor or switch, for a 4 L single flush.
Sensor or switch
Wave on kits flush when the user waves a hand at an infrared sensor; the anti vandal version's sensor is brushed stainless steel. Tactile switch kits use a stainless steel push switch. The programmable and direct flushing kits work on their default settings; the KWC DVS Handheld Programmer, sold separately, is only needed to change them.
Installation
Match the base to the cistern outlet, 1½" or 2"; in an existing cistern the valve replaces the syphon or old valve on the same flush pipe. Fit the control box in a dry place within 2 m of the valve and sensor, not on the washroom wall. 230 V kits need a fused spur; battery kits need no mains wiring. For new builds see concealed cisterns and frames.
Toilets with no cistern
The direct flushing kit flushes a toilet straight from the mains, under the pressure flushing valve rules below. For urinals see urinal fittings, and for other toilet parts commercial toilet fittings.
Regulations and standards
In England and Wales, the Water Supply (Water Fittings) Regulations 1999, Schedule 2 paragraph 25, cap a single toilet flush at 6 litres; the WC01 data sheets give 4 L. The direct flushing kit is a pressure flushing valve: it may not go in a house, or where 1.2 litres per second cannot be reached at the appliance, and it needs a vented pipe interrupter at least 300 mm above the spillover level of the pan. Set its flush time so each flush stays within 6 litres.
WRAS listing 2311323 covers the KWC DVS WC01 valve opened by a mains infrared sensor kit, as in the mains wave on, programmable and anti vandal kits; the battery and tactile switch kit sheets also state approval.
Where they are used
Schools
Mains control boxes can lock out after repeated flushes within 15 minutes, and the anti vandal kit's sensor is brushed stainless steel. See anti vandal toilets.
Offices
Sensor kits fit existing cisterns where the outlet matches, so the pans stay; plan a dry place for each control box. See commercial toilets.
Healthcare
Sensors flush without a touch, and mains control boxes can purge after 24 hours unused. See disabled toilets.
Frequently asked questions
What is a flush valve?
A flush valve is the outlet valve in a toilet cistern: it opens to let the stored water into the pan, then closes so the cistern can refill. It takes the place of the traditional syphon. The KWC DVS WC01 is an electronic drop valve in ABS plastic with an internal overflow, giving a 4 L single flush. Where there is no cistern, a pressure flushing valve fed from the supply does the same job.
Does any flush valve fit any toilet?
No. A flush valve has to match the cistern outlet, and the KWC DVS valve comes with a 1½" or a 2" base. In an existing cistern its overflow is trimmed to at least 20 mm below the cistern overflow. WRAS note R572 says that before a retrofit the installer needs confirmation that the valve is compatible with the toilet suite and that the suite still meets its flush performance requirements. Send us the cistern make and model and we will check the outlet size with you.
How does a sensor flush valve work?
An infrared sensor signals a control box, which opens the valve for a set run time and then lets it close. On the KWC DVS wave on kits the user waves a hand in front of the sensor; the data sheets list run times of 0.25 to 6.75 seconds on mains kits and 0.2 to 6.5 seconds on battery kits. The direct flushing kit runs its valve for 2 to 6.5 seconds, 4 by default.
Should I choose a mains or battery sensor flush valve?
Choose mains where you can bring power to each control box, and battery where you cannot. The 230 V kits are wired from a 3 amp fused spur and the programmable mains kits run from a 9 V DC mains power supply; battery kits run the control box at 9 V DC, on six C cells in the tactile switch kit. The data sheets give no battery life, so ask us. Programmable sensors come on an 800 mm cable; ask us for longer.
Can a toilet flush without a cistern?
Yes, outside houses, using a pressure flushing valve fed straight from the supply, such as our KWC DVS Programmable Direct WC Flushing Kit. Its instructions ask for ¾" full flow pipework delivering at least 1.5 litres per second, with the valve at least 2.2 m above the toilet's discharge level. In England and Wales the Water Supply (Water Fittings) Regulations 1999 also need a pipe interrupter with a permanent vent at least 300 mm above the spillover level of the pan.
Are your flush valves WRAS approved?
Yes for the KWC DVS WC01 valve, the valve in the DVS Flush Valve and our cistern kits. WRAS (Water Regulations Advisory Scheme) listing 2311323 covers it when a mains infrared sensor kit opens it, and the battery and tactile switch kits' data sheets also state WRAS approval. Ask us about approval for the programmable direct flushing kit before you specify it.
How much does a commercial sensor flush valve kit cost?
Our toilet sensor and switch kits cost from about £340 to about £520 ex VAT, or about £410 to £620 with VAT at 20%, which is added at checkout. Programmable battery kits cost about £100 less than mains. The valve alone is from about £200 ex VAT; the handheld programmer, needed only to change settings, is about £250. Delivery to England, Scotland and Wales is free, and we price match: see our price match guarantee.
How quickly can I get a flush valve kit delivered?
Delivery takes 1 to 3 working days. It is free to England, Scotland and Wales, including the islands, and costs £25 to Northern Ireland. Ireland, the Channel Islands, the Isle of Man and other countries are quoted on request. Call 020 4571 5856 or email sales@flushfittings.co.uk to check stock on a kit before you order.
