What is flow rate?
Imagine filling your bath. A low flow rate the bath will take longer to fill. A high flow rate the bath will be quicker to fill.
What is water pressure?
Imagine standing on a step and pouring water from a bucket, now imagine standing on a tall ladder and pouring water from a bucket, the same quantity (flow rate) of water will hit the ground but the water poured from a greater height will have more force (pressure).
Why should I be concerned about water pressure and flow rate?
Quite simply get it wrong and your taps / shower will be too powerful or nothing more than a dribble. The vast majority of brassware (taps and showers) sold in the UK today are designed to work on modern high-pressure water systems, they generally do not work well on low pressure systems without the addition of a pump.
How do I know what type of system I have?
Your installer should as a rule check both water pressure and flow rate when they carry out their survey. Some simple indicators are if you put your thumb over the cold water side of the kitchen tap the water will probably squirt out in all directions this is because generally the kitchen taps runs off the incoming water main. What happens if you put your thumb over the hot side of the bathroom tap? If the effect is the same it’s likely you have high-pressure. Do you have cold water tanks in the loft? If so it’s likely you have low pressure. Do you have a foam lagged cylinder in your airing cupboard? If so it’s likely you have a low pressure system.
I know I have a high-pressure system does that mean all brassware / showers will definitely work?
No, it is important to understand just because you have a high-pressure system this does not automatically mean you have enough high-pressure to your bathroom. Your installer can simply make a check using a flow cup and pressure gauge.