This Is How To Bleed A Radiator Without A Key

There are so many home improvements that can be done to create a wonderful space. From building a new wardrobe, fitting an electric shower and painting laminate kitchen cupboards, to treating damp walls. So, what’s more? When winter approaches, we all need our heating systems and hot water to work properly. If your radiators aren’t heating up as they should, the room will seem cold even if they’re turned up. If your radiator is cold to the touch on the top, the first thing you should consider after removing sludge is to “bleed” them. Now, what does bleeding mean? When the air becomes trapped inside the radiator, it might compromise the unit’s functionality, resulting in a partially warm or chilled space. 

Woman and child wearing socks warm cold feet in front of radiator

To open the valve and allow the air to escape, you need a radiator key. Unfortunately, sometimes, people don’t have such a key. Luckily, this doesn’t happen often. But, when it does, don’t give up! You can use many alternatives to bleed a radiator without a key, and in this step-by-step guide, we will show you how you can properly and safely do that. 

What heating system your radiator uses

You must first determine the type of boiler in your home before you can repair your radiator. Is it part of a steam boiler or a water system?

Steam system

You won’t find any bleed plugs if your radiators are part of a steam boiler, which is distinct from a water boiler. What you will observe is an air vent on the side. If the radiator isn’t working properly, cleaning the vent may help. 

Hot water system

These systems contain two pipes that allow water to circulate through them and back to the boiler. Look at the pipes connecting to the boiler if you need more proof that you have a hot water system.

One of them has an electric circulation pump linked to it. This pump is usually to blame if none of your radiators is getting heated. First of all, it might not be getting enough power, and secondly, it might be broken, which might be due to a tripped circuit breaker.

How to bleed your radiator without a key

You most likely already have all the materials needed at home for this effective DIY solution. The only thing you are missing for now is the radiator bleed key, and we will show you how you can use a flat screwdriver or compression joint instead. Let’s get down to business and go over them one by one:

Hand bleeding ratiator with flat screwdriver

Option 1: Flat screwdriver

Step 1: Take a look around

Bleeding radiators is a quite straightforward task. Begin by turning on your boiler and giving your radiators plenty of time to warm up. This allows you to quickly determine which radiators require attention and which can be left alone. 

Feel around the surface of your radiators for any chilly patches without burning yourself. It’s absolutely worth bleeding any radiators that make a strange noise when heating up or have spots that are cold at the top to keep your energy bills from skyrocketing.

Never bleed your radiator if you are not quite sure if there is a problem or not. This may end up causing more harm than benefit. For example, if you bleed a radiator with no air trapped inside, your boiler pressure may drop too low, causing your entire boiler to fail, which is the last thing you want. 

If you are wondering whether or not you can bleed a radiator when the heating is on, the answer to that is a big no, to say the least. You risk being burned by the hot air or water. You don’t want to end up in hospital because you tried to bleed a radiator.

So, once you’ve figured out which radiators to bleed, turn off the heat. Allow plenty of time for your radiators to cool down just to be on the safe side.

Step 2: Allow the trapped air to escape

After that, you can start bleeding your radiators and clearing the air from your boiler. Starting at the bottom and working your way up is a good idea. To put it another way, bleed your radiators downstairs first, then move on to the ones upstairs

Make sure your property is shielded from any dirty radiator water spillages before you start opening your bleed valves. To catch any liquids, place an old towel and a jar behind the valve. 

To open the valve, twist your driver anti-clockwise with an old cloth or a thick glove. Keep in mind that you should not open your radiator valve completely or for an extended period of time. If you let too much water out, your boiler’s pressure will plummet. 

Simply turn the valve until the hissing sound of air leaving is heard. Allow all air that’s trapped to escape until the sound ceases and the valve begins to release a steady stream of water. 

Now, you can re-tighten your bleed screw and voila! You are done. Once you’ve finished, wipe away any excess moisture or condensation to prevent rust from building around your radiator valve.

Option 2: Compression Joint

To bleed a radiator without a radiator key using a compression joint, you will also need a spanner or pliers. It’s also a good idea to keep towels on hand as the water starts to drip from the radiator. Here’s how to go about it:

Man holding wrenches bleed a radiator

Step 1: Turn off the heating system

You need to follow the first step of the screwdriver method once more. Check which radiators need bleeding and then move on with the task. Go to your thermostat and turn off the heat and wait for the radiators to cool down. This will keep you from getting burned. Next, loosen the compression joint where the towel rail meets the radiator with a towel. Do it slowly to avoid any accidents. 

Step 2: Release the trapped air

As air that’s trapped escapes the radiator, you should hear a hissing noise. Re-tighten the radiator bleed valve with the spanner once the hissing has stopped. You’ve now let out all of the trapped air. To prevent a large amount of water from escaping the radiator, swiftly tighten the valve. Next, restart the boiler and check the boiler’s pressure gauge. Fill it back up if the pressure is too low. Allow an hour for the radiators to heat up. Then double-check that the heat is dispersed evenly across them. 

How can you know if you did it right?

Double-checking that your efforts have paid off is the most important thing you can do after you finished bleeding the radiator. Check the pressure in your boiler first. After radiator bleeding, it’s expected that the pressure drops significantly. When switched off, it should be about 1.0 – 1.5 bars, and when switched on, it should be about 2 bars.

If your pressure gauge has dipped too low, which can happen, you may need to re-pressurise your boiler using a filling loop or contact your heating engineer for assistance. On the other hand, if the pressure in your boiler looks to be normal, it’s time to do a “heat test”. 

Restart your central boiler and give your radiators a new feel. There should be no more cold spots if all goes well, allowing you and your family to enjoy the comforts of a warm house while also saving money on your heating bills. It’s a win-win situation.

Why you should bleed your radiators

When there is air trapped inside a radiator, warm water cannot circulate around it. As a result, you will have a radiator cold at the top and warm at the bottom. This means that your central boiler isn’t working properly, which in turn, will take longer for your room to warm up. It may also cost you money because your bills will be higher as a result. 

When to bleed your radiator

Don’t know if your radiators need a little “bleeding”? No need to worry! Below are some of the indicators that you should keep in mind:

Woman's hands on ratiator

1. When the radiator is squeaky

Your radiators may create strange noises like gulping, gurgling, and rattling due to air that’s trapped in your boiler. While this could be due to various factors, it could also indicate that the radiator needs to be bled. In any case, you should examine it to ensure that the issue isn’t more serious.

2. When there is mould or wetness around the house

If you’ve observed some wet, cold patches or mould on the walls, especially in rooms that aren’t used very often, it’s a clue that there may be a build-up of sludge, and your radiator needs to be cleaned and bled.

3. The top of the radiator gets cold

This is the most typical symptom when your radiator requires bleeding. The air has accumulated in there, preventing water from circulating and heating it, which means that it must be released in order for your radiator to heat up properly. Patchy warmth in your radiator is a warning that it should be checked out too.

4. The whole radiator is ice cold

Though this isn’t as prevalent as air trapped in radiators, it is undoubtedly a symptom that your radiator requires maintenance. The water that was supposed to flow into it has been slowed by trapped air in the pipes. If not addressed quickly, this might lead to more serious issues in the future. 

In the grand scheme of things, it may seem impossible to bleed a radiator without a key. However, as we have demonstrated, all it takes is a little creativity and a few extra tools. Now you know how to bleed a radiator yourself without having to resort to a plumber or any boiler service!

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