How to Bleed a Radiator in 6 Simple Steps

Learning how to bleed a radiator is an valuable skill for those cold winter mornings. As experienced plumbers with decades of experience, we know all about what it takes to keep your home warm this Winter, so get your radiator key and cloth at the ready and follow along with our in-depth guide on on how to bleed a radiator.

To make life easier, here are 6 simple steps on how to bleed a radiator:

Step 1: Turn off the heating – Switch off your central heating and let the radiator cool fully. This prevents burns and makes the job safer.
Step 2: Find the bleed valve – Locate the small square valve at the top corner of the radiator, this is where the air will be released.
Step 3: Open the bleed valve – Insert a radiator key or flat-head screwdriver and turn it slowly anti-clockwise (about a quarter turn).
Step 4: Release the air – You’ll hear a hissing sound as trapped air is released. Keep a cloth underneath to catch any drips.
Step 5: Close the bleed valve and clean up any leaks – Once water starts to trickle out steadily, turn the valve gently clockwise to close it.
Step 6: Repeat

For more details, watch our helpful video or continue reading on below.

Being an integral part of your household during the colder months, radiators need to heat properly and perform to the best of their ability. However, we have all been there touching the cold metal top wondering why it is not heating up. This is when it’s time to bleed your radiator of the build up of gas and air from within.

What does it mean to ‘Bleed’ a Radiator?

Bleeding a radiator can be somewhat of a daunting task if you are unaware of what the process is.

Once your radiator is on and heated up, you may find that the top of the radiator is much cooler than the bottom. This is when you know it is time to bleed the radiator.

The process involves the removal of air from within the radiator. As time goes on, air naturally builds up within the radiator, preventing the circulation of the water.

This therefore stops the radiator from performing to its maximum efficiency. However, by regularly bleeding the radiator, you can keep the radiator working effectively to keep your house heated.

Why do you need to Bleed a Radiator?

To have your heating system working effectively and keeping you warm on those cold winter days, it’s important to bleed your radiators regularly.

The air that builds up and gets trapped inside your radiator stops the circulation of the water which heats up the chamber. By releasing this air you can enjoy hot and efficient radiators around your entire house.

What Tools do I need to Bleed a Radiator?

Bleeding a radiator is very straightforward, however you will need to acquire a few items before beginning:

A radiator bleed key or a flathead screwdriver
A container to catch excess water
A towel or cloth to wipe up water spillage

Bleeding a Radiator: Step-by-Step Guide:

Bleeding a radiator is a simple six step process that guarantees your house will stay warm this winter.

1. Turn on the central heating and feel your radiators

The first step is to identify those radiators that need bleeding. Turn on your central heating, ensuring your radiators are on high. Once they are heated, go around and identify which radiators are cold at the top. This indicates that they need bleeding.

2. Turn off the central heating and let the radiators cool

After you have identified the radiators which need bleeding, turn off the heating and let the radiators cool all the way down.

3. Find the radiator bleed valve

Find the bleed valve on your radiator. This is typically located on one of the sides towards the top.

4. Place container beneath the bleed valve

Place your container of towel beneath the bleed valve, this will catch the water as it releases.

5. Bleed the radiator

Use your radiator key or flathead screwdriver to turn the valve anticlockwise slowly until the radiator begins hissing. This will release the air from the radiator and begin hissing. Once the hissing stops, water will begin to come out. Turn the valve clockwise to tighten and clean up any spillages.

Follow steps 3-5 for each radiator that feels cold to the touch to ensure each one is performing efficiently and keeping you warm this winter!

6. Turn the heating back on

Once you have successfully bled your radiators, turn back on the heating and feel your radiators once again. Now you should feel a consistent heat from top to bottom within your radiator.

How GK Plumbing & Heating can help

Hopefully this guide has helped you to bleed your radiator and keep your house warm as the temperatures continue to drop. However, if your radiator remains cold, there may be a further underlying issue.

If this is the case, get in touch with one of our qualified plumbers and we can come and take a look.

Wondering when to replace your current radiators? Keep an eye out for our next article looking at how often radiators should be replaced.

How to Bleed a Radiator