Guide to bathroom water pressure

If someone’s been living in a home for a while, it can be difficult to know if the bathroom water pressure has changed or if it’s at the level it should be. Homeowners often don’t realise their water pressure is too low or high, as it can feel normal if the change happens gradually over time.

That’s why it’s important to understand and check water pressure so you can ensure clients’ showers, baths and taps are working properly. This guide will take you through reasons the water pressure could be wrong, how to test bathroom water pressure and what’s needed to fix any issues you find.

 

What is water pressure and how is it affected?

Water pressure is how quickly water flows through the pipes for bathroom appliances, so it has a massive impact on the quality of showering and how fast a bath fills up. The force of the water is measured in bars, with one bar being enough to push water up to the height of 10 metres.

Water pressure systems are different for each property. It can even vary depending on the room and the time of day. During the morning, for instance, some might experience low water pressure in the bathroom because other houses in the area will be using their showers and baths at the same time.

 

Types of water pressure systems

There are three different types of systems that will influence water pressure supply and the standard measurement of water pressure in the bathroom. Understanding the system in a particular home will give you a better idea of what level the pressure should be running at.

Gravity fed heating system

This type of system is typically found in older homes, featuring a cold-water storage tank and a hot water cylinder. Gravity fed systems usually operate at quite a low water pressure, so expect bathroom taps and showers to be running at around a 0.2 bar rating.

Combi boiler system

Combi boilers are fed with water from the mains pressure supply, which it then pumps around your home at about the same level of pressure as the mains. If a combi boiler system is in place, water pressure will be high. Taps and showers should normally be around 1-1.5 bar.

Unvented system

Unvented water systems are made up of just a main cylinder, which is filled directly from the water mains and maintains a high pressure level. With this setup, bathroom appliances will be running at about 2 bars.

 

How do I find out my water pressure?

Now that you’ve got an understanding of what water pressure to expect in the bathroom, the next step is to find out the water pressure reading so you can compare.

Your first option is to get in contact with the water supplier as they’ll have the skills and equipment to deliver a precise reading for you. Alternatively, you can test the pressure yourself with a pressure gauge, which can be purchased online or at a plumbing outlet.

Here’s a step-by-step process to measuring bathroom tap pressure with a pressure gauge:

1. Ensure no water is running
2. Attach your gauge to the tap
3. Turn the tap on fully
4. Jot down the reading and compare it to your expected pressure rating

How can I test the water pressure for my shower?

There’s also a way you can work out if the shower pressure is working properly. This is without the use of a pressure gauge, however, so you’ll be calculating the water flow rate instead. While you won’t be able to get an actual pressure reading, this method still provides a good indicator of how the shower is performing. You’ll need a measuring jug, a calculator and a stopwatch to carry out this test.

1. Place your jug under the shower head
2. Turn on the shower and fill the jug for exactly six seconds using the stopwatch
3. Measure the amount of water in litres and multiply this by 10 which will give you the water flow rate per minute

Your measurement should fall into one of the following rankings. This will indicate the level of the water pressure in the shower:

• Low flow rate = Less than 10 litres
• Normal flow rate = 10-15 litres
• High flow rate = More than 15 litres

 

Why is the water pressure low?

After testing the bathroom appliances, you may find the water pressure is lower than it should be for that particular system. If this is the case, there are several factors you need to consider to help you diagnose the problem. These are the main causes:

• Build-up of hard water deposits. These deposits can block the valve, aerator, pipes or showerhead.
• Blocked pipes can affect bathroom water pressure. Blockages happen as rust and minerals clog the hot water output.
• A leak may have occurred. This a serious incident that can damage the structure of the property.
• If none of the above apply, there could be a problem with the water mains supply. This should be reported to the local water provider so they can fix the issue.

 

How do I increase water pressure in my bathroom?

There are a few ways you can increase bathroom water pressure should you discover it’s too low:

• Clean or replace pipes – Clean and remove hard water scale and sediment build-up inside the plumbing lines. Or, replace the old pipework.
• Correct taps and shower head – Make sure the taps and showers are suited to the water pressure system. For example, a tap that requires a high bar rating to function won’t perform properly with a low-pressure system.
• Install a power shower – The appliance uses a built-in electric pump to provide a stronger jet of water.
• Fit a shower pump – Shower pumps increase water pressure in the pipes before it comes out the shower head.

For more useful information on improving water pressure, check out our article here.

 

What if my bathroom water pressure is too high?

High water pressure should be fixed quickly as it can pose many problems for a home, including:

• Wasted water and more costly water bills
• Plumbing leaks and subsequent damage
• Shortened lifespan for a water heater
• Boiler and piping damage

The root of the problem will usually be the water regulator which is found where the mains enters the home. You’ll have to tinker with the water pressure for the entire property rather than just the bathroom.

Adjusting a water regulator

Best-case scenario, you’ll have to adjust the water regulator. Here’s how:

1. Locate the water mains valve and turn it off
2. Loosen the locking nut on the regulator using a wrench
3. Use a screwdriver to turn the screw on the regulator anti-clockwise in small increments. This will decrease the water pressure
4. Test the water pressure to see if it’s now in the correct bar range. If not, adjust the regulator again accordingly
5. Once you’ve achieved the right pressure level, secure the lock nut on your regulator
6. Turn the water mains valve back on

Replacing a water regulator

You’ll need to replace the valve if the regulator is no longer reducing water pressure. Here’s the step-by-step process:

1. Turn off the water at the mains and run a faucet to empty the pipes.
2. Grab hold of the pipe below the deice and turn it using a wrench.
3. The pipe and regulator should gradually separate, at which point you can remove the old regulator.
4. Place the new regulator into the pipe. Bear in mind you might need a pipe fitting if the regulator end is too large.
5. Next, tighten the pipe connected to the regulator to keep it in place.
6. Program or switch on the regulator and make sure it’s running at the desired level of water pressure.
7. Finally, turn the water mains back on and check there aren’t any leaks around the pipes.

Installing a water regulator

You may find that the property doesn’t even have a water regulator. It would be a good idea to install one to ensure water pressure is kept at a normal level. Regulators can be purchased for around £35.

 

FAQs

Is 2.5 bar water pressure good?

Whether this reading is good will depend on what water pressure system is installed in the home. You’ll need to compare what bar range is suitable for the property.

 

What does 3 bar water pressure mean?

As mentioned, water pressure is the force of the water moving through pipes and is measured in bars. This is enough force to raise water to a height of 30 metres. This is considered high.

 

What is the best water pressure for a tap or a shower?

The best water pressure for a tap or shower will depend on what water system the property has in place. Note, low water pressure only in showers might indicate a problem with the unit, while low pressure in bathroom taps is more likely to be down to a problem with the home’s plumbing network.