Pressure and flow rate

Pressure is the force that pushes water through the pipes. Before you install any flow-restricting devices or low-flow showerheads, it is important to know whether your hot water cylinder has mains (equal) water pressure or low (unequal) water pressure.

Some flow-restricting devices and low-flow showerheads are not compatible with hot water cylinders with low (unequal) water pressure. Talk to your plumber and strictly follow manufacturers’ instructions.

Most hot water cylinders show whether they are a mains (or equal) water pressure or a low (unequal) water pressure cylinder. If you are unsure, here are two indicators of a lowpressure cylinder:

• Your shower temperature and/or pressure changes when someone uses hot water elsewhere in the house.
• Your cold water tap runs faster than your hot water tap.

Other types of hot water systems include instantaneous/continuous gas and electric where there is no storage of hot water. These systems are usually compatible with water-saving devices but consult your plumber, and strictly follow manufacturers’ instructions.

The flow rate is the amount of water flowing from your shower or tap. Measuring the flow rate is simple and takes just a few minutes.

You will need:

• A bucket or large jug with measurements.
• A stopwatch (or count off 10 seconds).

Steps:

1. Turn the shower or tap on to its normal setting and let it flow into the bucket for 10 seconds.
2. Measure the amount of water in the bucket and multiply it by six.
3. Use the chart below to check whether your shower or tap flow rate is excellent, average or excessive.

If all your showers and taps have an excessive flow rate, you may want to discuss solutions with your plumber rather than putting flow restrictors on all of your appliances.

Flow restrictors limit the amount of water that is let out of the tap or shower, so you can reduce the amount of water you need for things such as showering or washing the dishes. Your hardware store should have a variety of restrictors to choose from.