Cistern comfort & class

Jagvir Goyal

Flushing cisterns constitute a small but important item among the hundreds of items purchased by a house builder in completing his house. These, however, occupy a high rank on the Importance Index of the items. If a flushing cistern becomes unoperational, an emergency situation arises and it has to be got repaired immediately and can’t be left unattended for days together. Special attention should, therefore, be paid while choosing flushing cisterns. Let’s have a look at the various types available in the market and their plus and minus points:

Flush valves: There was a time when flush valves were commonly used with the water closets (WCs) instead of flushing cisterns. The main reason behind their choice was that no cistern was needed to be installed and, thus, more space was available in the bathroom. Most hotels, commercial establishments preferred to use flush valves in their buildings. With hotels, flush valves have been a favourite item as they tried to provide smaller attached baths with the rooms yet wanted these to look spacious.  

In flush valves, a simple lever is visible to operate them. Flush valves, however, have two major drawbacks. One is that these draw large volumes of water from the water tank, causing wastage of water. Sometimes, the tank goes completely empty. Second drawback is that these make lots of noise during night as all the water contained in the pipe above the valve gets drained under gravity. Noise is so loud sometimes that a person sleeping in the attached room is abruptly woken up by it. It has further been noticed that after sometime, the lever of many flush valves stops operating smoothly. The user has to keep it pressed down to draw sufficient water in the closet. In other cases, the situation is reverse. It becomes difficult for the user to stop the water and he keeps pulling the lever up to stop the water from flowing into the water closet.  

Many cities have now banned the use of flush valves. The ban needs to be extended to more areas in order to save water. Users, on their own, should avoid using flush valves for noiseless use of toilets and to save water.

Wall cisterns: Use of wall hung seats has become common now. Rarely, does a person choose floor mounted seats these days. Commonly, these seats are provided with a wall hung cistern. Overhead cisterns with long dangling chains and often erratic in flushing operation have almost disappeared from the market now. Low level cisterns, both for Indian as well as English seats are ruling the market. Users are more or less happy with these because of their low cost and smooth operation. In case of a problem in low level cisterns, these are easy to repair and any plumber easily fixes them. The cistern knob is convenient to press and the water pressure is excellent.

If PVC pipe is used as flush pipe, it should have larger diameter of 50 mm for proper functioning of WC and cistern. To save water, dual flushing cisterns should be chosen. Such cisterns discharge partial or full quantity of water as per requirement. Earlier, the partial and full discharges were 5 litres and 10 litres, respectively. Now, the manufacturers have come out with 3 litre-6 litre combination. A cistern should not take more than 6 seconds for full discharge and 3 seconds for partial discharge.

Touchless flushes: The manufacturers have now come out with touchless flushing cisterns which discharge water automatically when you stand in front of the seat or just hold your hand above the tank sensor to activate the flushing. Many people avoid touching the actuator plate or flush cistern handle. For them, this is the ideal choice. There is no waiting for a refill of the cistern and there is no noise of refilling. Water used is just 6 litres, matching with water conservation norms. As advanced electronic systems are used in these flushing systems, some manufacturers provide a mechanical button also for use in case of power failures.

With so many flushing systems available, the house owner is the king who can choose a system suitable to his budget and easy for him to operate.

Vacuum systems

The manufacturers have now come out with another flushing system called vacuum flush system. These flushing systems can be installed in the normal pipeline of 20 mm diameter. In a house, ½ inch and ¾ inch diameter pipes are most commonly used. However, for a flushing cistern, normally 40 mm diameter pipe is used. In case of this flush system, there is no need of providing 40 mm diameter pipe and flush mechanism can be installed in the 20 mm diameter pipeline itself. Vacuum flush system can be provided in 4 ½ inch thick walls also. In case of concealed cisterns, as the cistern is minimum 3 inch thick or more, it is preferred to be accommodated in a 9 inch thick wall. If the wall is 4 ½ inch thick, we provide separate ledge wall to accommodate the concealed cistern. That problem gets omitted in case of vacuum flush systems. Another advantage of these cisterns over concealed cisterns is that in case of concealed cisterns, one has to wait till the cistern gets filled up after use. However, in case of vacuum flush system, no such waiting is required and repeated flushing can be done. Vacuum flush systems have in-built control systems. These use just six litres of water for full flushing while three litres of water is required for half flushing. Another advantage of these systems is that these can work at a very low pressure. Tested for noise reduction, these produce minimum possible noise that doesn’t disturb the other occupants of the house. Though the manufacturers assure their maintenance- free operation for years together, in case of problem, their control system is first closed with the help of a control key and then the system is assessed by removing the actuator plate. These systems, in fact, work by creating vacuum in the pipeline and give optimal performance. Above all, these systems, though new and latest inthe market, compete well with the existing systems on cost front also.

Prefer chinaware

Though wall cisterns are available in plastic materials yet preference should be given to chinaware cisterns matching in colour with the water closet. White colour is the common and preferred choice. Coloured seats and cisterns attain ugly stains and spots with time and should be avoided. While selecting chinaware cisterns, the most important item to check is their glazing. Chinaware items are classified as first and second quality items depending upon their glazing quality. One should always choose ‘first quality’ products and avoid ‘commercial quality’ products. Further, a reputed make should be chosen. The cisterns must be minimum 6 mm thick. The vertical flushing pipe should be at least 300 mm long. It should be of minimum 38 mm internal diameter. 

Concealed cisterns

Concealed cisterns are these days suggested as the ideal choice for attachment to a wall-hung seat as these occupy no space. These are concealed in the wall and just the actuator plate is visible on the wall to press it. Concealed cisterns are now just 3-inch wide and can,  therefore, be easily concealed in the wall. Mostly, High Density Polyethylene (HDPE) is used for the manufacture of body of concealed cisterns. The actuator plate is made of high quality plastic, metal or stainless steel and is attractively finished. It has double press buttons on it for dual flushing. Concealed cisterns are supposed to be noiseless and produce a sound of less than 20 decibels which is barely audible.

Concealed cistern technology is well developed now and the manufacturers vouch for zero maintenance for these. However, in case of problem, provision exists to remove the actuator plates to allow access to the inside of the cistern. Best quality cisterns are blow molded as a single piece. So there is no chance of any leakage. 

— The writer is HOD and Chief, Civil Engineering Department  in a Punjab PSU