Water flow is the amount of water you receive and depends on the size of the pipe that connects your home to our water mains.
As an example, a small pipe will only receive enough water to run one tap. If several taps or appliances are connected to the same pipe there may not be enough water coming through for all of them to be used at once. You will then have 'low flow' - perhaps just a trickle of water coming out of the taps.
In older properties, pipes were half an inch (12.5mm) in diameter. Sometimes, a half-inch pipe laid by the landlord or developer was adequate to supply a row or group of houses.
This can often cause low flow problems when people use water at the same time, especially when modern appliances such as dishwashers, washing machines and power showers are used.
The first appliance turned on will draw most or all of the water from the pipe and there will not be enough for any other taps or appliances.
This can be a particular problem for people living in converted houses. Generally the ground floor receives adequate flow but higher floors may require the installation of additional pumping arrangements.
Modern houses and flats usually have bigger pipes - 25mm diameter (outside diameter). This means the water flow will be much higher, so there is enough for several appliances to be used at once.