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How to bleed a radiator heater without a key

How to bleed a radiator heater without a key

Do you have a system of radiators to heat your home in the winter? If so, you have a boiler, usually in the basement which supplies the radiators with hot water, and must circulate completely through each radiator in order to ensure all radiators are heating efficiently.

TIP: Be sure to check out our other radiator-related articles such as when to turn the heat on, what to do when the radiator’s not getting hot, and how to bleed a radiator
 so you can understand the entire process of how the radiator works.

However, if air gets into the system, it will tend to collect at the top of each radiator and create a barrier. Each radiator has a bleed plug to allow the air to be flushed out so that the radiator can return to its highest efficiency. This plug is located on the side or near the top and has a special shape that fits a unique radiator key to bleed the air out. Easy right?

But can you bleed the radiator without a key? YES! A number of tools can stand in and do the job.

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Identify the type and shape of the plug fitted onto the radiator

First things first! You must determine which kind of fitting or plug that is already built into your specific radiator, so you can locate an alternative tool that will do the trick to open the valve. Once you locate the right tool, insert the tool into the slot and turn it counter-clockwise to bleed the air out of the top of the radiator. Have a clean towel handy and a small cup to catch any water that might drip out of the radiator.

Do not walk away from this project once you get the bleeding of the radiator under way. When the air is finished “bleeding” a few gurgles of water will come to the point of the valve and at that time, you must have the tool to close the valve. Let’s get started on how to bleed a radiator heater without a key. Here are the most common shapes.

1. Slotted Bleed Screw

  • For radiators with a slotted bleed screw, a simple flathead screwdriver can be a perfect alternative to a bleed key.

2. The Square Nut

  • For radiators with a kind of square nut in the plug, grab your socket set and choose the socket that fits over this plug.
  • You could also use a spanner tool or a pair of pliers to open the valve.

3. Hexagonal Nut

  • Some plugs look like security screw heads, with a hexagonal orifice inside of which is a square or hexagonal nut. The nut prevents you from substituting a hex wrench or screwdriver for the missing key, but you can usually fit the jaws of a pair of needle-nose pliers into the orifice to grab the nut and turn the plug.

4. Hexagonal Socket

  • You may also come across bleed plugs with a hexagonal socket. The radiator key for this type of plug is basically an Allen key. When you bleed the radiator without the key, you can simply use an Allen key (or sometimes called an Allen wrench) of the same size.
  • No Allen keys in the house? A flat-head screwdriver often makes a suitable Allen key substitute. If it's slightly smaller than the socket, wrap duct tape around the head to make it fit.

We hope you enjoyed our tips on how to bleed a radiator without a key. Don’t forget to check out our other DIY and cleaning tips such as how to fix a clogged toilet, what to do when the radiator is hot at the top and cold at the bottom, and how to clean a water heater.

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