No Bleed Valve On Radiator? Here’s What To Do

Now we’ve talked about radiators a lot on DreamyHome. In that time, I’ve taught you how to pinpoint bad noises, fix radiators that won’t heat, and shown you how to bleed a radiator. That is, I’ve taught how to bleed a normal radiator. But what if there’s no bleed valve on your radiator? That changes things slightly, and it’ll depend on the type of radiator you have.

If there’s no bleed valve in your radiator, you can still bleed it – just in a different way.

Let’s break down what to do and how so you can have a properly functioning radiator!

Why Bleed a Radiator?

First things first, let’s talk about why you even need to do this. There are a lot of reasons to bleed a radiator, though the biggest one is that you’re supposed to do it annually – something a lot of people forget. If you notice odd noises or a lack of heat, those are also good cues to start bleeding the thing.

In summary:

  • Noise – This is often caused by air being trapped in your radiator. If you hear a rattling or gurgling noise, it’s your cue to get bleeding.
  • No heat – If your radiator is either not working at all, or parts of a single radiator have gone cold, that’s a great sign to bleed the thing. Air gets trapped often in your radiator and can prevent proper movement of steam (and therefore heat) in the machinery. A bleed fixes this.
  • Bleed your radiator at least once a year – Even if it seems like they’re in perfect condition, it’s good to do this. Generally, you’ll want to do it at the start of winter as you are using your radiators for the first time of the year.

How to Bleed a Radiator, 3 Ways

Let’s start on how to bleed a radiator with a bleed key and valve, as that’s super easy and good general knowledge to have. Begin by:

  1. Lay down towels and a bowl. You will have water coming out, so it’s good to catch it before it makes a mess.
  2. Crank the heat in your home for at least ten minutes to allow your radiators to reach max heat. Once they’re as hot as possible, turn the radiator(s) you’re bleeding off and allow them to cool, which usually takes about an hour.
  3. Turn your bleed key to open your bleed valve. This is done with a screw or specific mechanism that fits your key – remember; lefty loosey, righty tightey.
    1. If you don’t have a key, an Allen key, wrench, screwdriver, or pliers work as well.
  4. You’ll hear a hissing noise – that’s okay. Keep the key turned until water starts to come out or the hissing stops, usually after around 30 seconds.
  5. Close the bleed valve, turn your radiator back on, and test. Check your boiler pressure and repressurise as needed by adding water to the external filling loop of your boiler. Repeat as necessary.

Now – what if your radiator doesn’t have a bleed valve?

Radiator With Towel Rail or Compression Joint

First things first, you’re going to need a wrench. Towels and a bowl are also useful, for the same reason as above – to catch water as it comes out. Now:

  1. Just as before, crank the heat in your home and allow the radiator to heat up. Once it has (~10 minutes), turn off the radiator(s) you’re working on and allow them to cool, usually about an hour.
  2. Loosen the compression joint where the towel rail joins the radiator. Undo the nut slowly (with a towel on your hand) until you hear a hissing noise.
  3. Let the hissing continue until water comes out, or the hissing stops. This usually takes about 30 seconds.
  4. Tighten the nut by hand until you can’t, then grab the wrench. Tighten again, cleaning up any water that came out.
  5. Turn the heat back on and check your pressure gauge on the boiler.
  6. Leave the radiators to heat for ~an hour, and check that they’re hot across the entirety. If not, repeat the process. If they are, well done! You just bled a radiator.

Now, that was the easy one. Now we move onto the more fun way to bleed a radiator.

Radiator Without Towel Rail or Compression Joint

First off, you’ll need a special tool if your radiator has neither a towel rail, compression joint, nor bleed valve. It’s called a self-drilling radiator valve, which you can buy at most hardware stores for cheap. It’s essentially a makeshift bleed valve that you install right onto the radiator. You’ll also need towels, a wrench, a cordless drill, and some hands – you do have those, right? Now, what to do?

  1. Repeat step one of the above. Heat your radiators, then allow them to fully cool.
  2. Turn off the heating and close off your radiator valves.
  3. Use your cordless drill to screw the self-driling radiator valve (ironic that it needs to be drilled in) onto the top of your radiator.
  4. Open the radiator valves.
  5. Slowly open the new self-drilling radiator valve, counterclockwise. Use the cloth to wipe up any water that comes out.
  6. Keep the valve open until the hissing noise stops, or until water comes out. Now, retighten the valve with your wrench, preventing a major water spill.
  7. Turn the heating back on, check your boiler pressure, and allow it all to run for at least an hour.
  8. Success

Final Thoughts

Bleeding a radiator is never a difficult task. If you’re missing a bleed key, you can sub out a wrench, pliers, or screwdriver in a pinch. If you’re missing the bleed valve, though, you’ll need a specialised part and some ingenuity. Should your radiator have a towel rail or compression joint, the process is pretty much the same as a standard bleed, but without a key.

If you need the self-drilling radiator valve, all that changes in the process is the installation of the valve, which is very easy. You just need a power drill and a wrench to get that done – no problem! If, however, you’ve bled your radiator and the issue hasn’t resolved itself, it’s time to call in the cavalry. Get a professional to take a look – there’s no harm in a bit of help. Plus, then you get to sit back and make a drink while the professionals do what they do best!

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About the Author Harry Thompson

Involved in home renovations throughout his life, Harry is an expert in everything to do with home and garden DIY. In his spare time, he enjoys cooking and tending to his garden.