A quick guide to bleeding a towel radiator
Over time air can build up in radiators causing them to be colder at the top than the bottom.
This makes your heating system less efficient, so it has to work harder to heat the room to the required temperature, which in turn results in higher energy bills.
This problem can be very easily fixed if you bleed the heated towel rail to remove the air.
Watch the video guide or follow the simple steps below for full instructions on how to bleed your heated towel radiator, and have it heating your room again, in no time.
What does ‘bleeding’ mean?
Bleeding is the process of getting rid of any air that has accumulated at the top of your towel rail.
This air stops water circulating through all parts of the towel rail. This means that the overall efficiency of the central heating system is therefore reduced and can cost you more.
Bleeding the towel rail involves simply opening a small valve and allowing any trapped air to be expelled.
How will I know if my towel rail needs bleeding?
You may notice that the towel rail is not heating up and, specifically, the top rungs of the rail are colder than the bottom ones.
You may also have heard knocking or tinkling through your pipes and radiators. This is usually caused by trapped air and bleeding will normally solve this.
If the issues aren’t fixed by bleeding your heated towel rail then you may need to contact a professional to diagnose the problem.
How do I bleed a heated towel rail?
To bleed a heated towel radiator, you will need a few tools:
- A radiator key or slotted screwdriver
- A rag
- A towel
- A spanner/hex key.


BestHeating always recommends using a radiator key wherever possible. These can be bought at local DIY stores. This is to avoid damage to the bleed valve.
Step 1 – Turn the heating off

Firstly, turn off the central heating as otherwise, you may soak air back into the system.
Step 2 – Allow the towel radiator to cool

Allow the water inside the towel radiator to cool down for around 20 minutes to ensure you do not run the risk of scalding yourself.
Step 3 – Open all valves

Ensure the lock-shield and thermostatic radiator valves (TRV’s) are open if present. To open, remove the caps and open them fully anti-clockwise using a spanner or a hex (Allen) key.
Step 4 – Locate the bleed valve

Find the towel radiator bleed valve. It tends to be at the top of the towel rail but is sometimes at the back. The screws are generally hexagonal or square. Also, many of them have a slot across the front so you can use a slotted screwdriver if a radiator key isn’t available.
Step 5 – Turn the valve anti-clockwise

Get your towel or rag and place it on the floor underneath the bleed valve. Using your radiator key turn the bleed nipple anti-clockwise. You should now hear a hissing noise. This is the steam and air leaving the radiator.
Step 6 – Let the water flow

Once the air has left the towel radiator, bubbling water will follow so catch it in a rag and turn the bleed nipple back and close.
If the air stops coming out of the radiator but no water follows, your heated towel radiator has most likely run out of pressure completely so this will need to be topped up using the filling loop.
Step 7 – Check the pressure of the boiler

Check the water pressure gauge on the boiler and follow the user instructions for your specific boiler to top up the pressure.
On open vented systems it should refill automatically.
How often should I bleed my towel radiator?
For a well-maintained heating system, annual bleeds are fine.
It is also advisable to bleed a heated towel rail after any modifications, repairs or when the towel rail feels colder at the top.
If you find you are bleeding your towel rail continually, please contact a professional.
Get in touch if you need a hand
If you’ve got any burning questions or need advice from the experts, be sure to send us your questions. We may feature them in our next blog post, too. Questions can be sent via the comments section below, Facebook or Twitter.
Please note: Our ‘How-To’ manuals are intended only as a guide to assist you with common home heating tasks. Please do not attempt to undertake this task if any of the instructions are unclear, or if you are in any doubt about what to do. Instead, seek advice from a professional.

John trained in journalism before finding his way to the BestHeating Advice Centre team. He uses his journalism skills to meticulously research heating topics and bring you the latest news and views on all things home heating related. He’ll also beat you at any sport that involves a cue!