A radiator that needs bleeding has cool air trapped in its upper portions. Thus, when you turn on the heat, either the entire radiator will feel cold or the top of the radiator will feel cold while the bottom feels warm. Unfortunately, a cold radiator can also signify other problems. Before proceeding, check for these other common radiator issues listed below. If none seem to fit, your radiator probably needs a simple bleeding. Be careful - radiators can get quite hot. Protect your hands when you're feeling a radiator for warmth.  If you have multiple radiators in your house and all of them are cold or lukewarm, you probably have a larger issue with your heating system - your water heater may be malfunctioning or you may have a buildup of sludge or sediment somewhere in your heating system (see: How to Flush a Water Heater.) If your radiator problem is accompanied by an accumulation of water beneath the radiator, your radiator has a leak. Try turning your heat off, then tightening the nut(s) on your radiator's inlet valve. If this doesn't fix the problem, the nut may be corroded - replace them or call a professional. If the radiators on the upper floors of your house aren't heating up but the radiators on the lower floors are, your heating system may not be operating at a high enough pressure to get hot water to the top floors of your house. If you've decided to bleed your radiator your first step should be to find something to open the radiator's "bleed valve." Look for a small valve at the top of one end of your radiator. On this valve, there will usually be small square bit which can be turned to adjust the valve. Radiator keys, cheap metal implements designed for opening and closing radiator valves, are available at most hardware stores. Find a radiator key that's the correct size for your valve or, alternatively, search your tool chest for a small wrench or other tool that's the right size to turn the valve.  Some modern radiators are equipped with valves that are designed to be turned with a simple flathead screwdriver.  Before proceeding, make sure you have a radiator key, a screwdriver, a wrench or some combination of implements so that you'll be able to open the valves on  every radiator in your house.  When bleeding one radiator, it's best to bleed every one in a house. . Ensure that your central heating is switched off before bleeding, as an active heating system can introduce more air into the system. You want your radiator's contents to settle completely before releasing the air trapped within. Allow time for the heat in your system to dissipate, then feel all over your radiator for heat. If any part of your radiator is still hot, wait for it to cool completely before proceeding to the next step. Ensure that both the intake and exit valves of the radiator are turned to the "open" position. Then, insert your radiator key (or screwdriver, etc.) into the  the bleed screw in the bleed valve at the top of the radiator. Turn the screw counter-clockwise to open the valve. You should hear a hissing sound as air escapes from your radiator. Opening the bleed valve allows trapped cold air to escape, which is replaced with liquid from your heating system via the pipes connected to your heating system. As air escapes from your radiator, water will likely sputter from the bleed valve. Hold a kitchen towel or cloth under the bleed screw to catch any drips. Alternatively, use a small bowl or dish. When a steady stream of water (not a sputtering mixture of air and water droplets) squirts through the bleed valve, you've released all of the air trapped in your radiator. Re-tighten your bleed valve (turn the bleed screw clockwise) and ensure that there are no leaks. Use a rag to wipe up any water that's splashed around your radiator. To ensure all excess air has been drained from your heating system, it's best to bleed all of your radiators, even if you've only been having problems with one. For a well-maintained heating system, you should try bleeding your radiators regularly. An annual bleeding plus a bleeding after any repairs or modifications to your heating system is usually plenty. By releasing excess air from your radiators, you've lowered the overall pressure of your house's heating system. If the pressure's fallen too low, heat might not reach some of your radiators (especially ones on the top floors of your house.) To restore your heating system's pressure, it may be necessary to top off your boiler with water.  For residential heating purposes, a pressure level of around 12-15 psi should suffice. The higher the pressure, the greater the height the height that heat from your system will be able to travel. Especially short or tall houses may require lesser or greater boiler pressure, respectively.  If your boiler has an automatic fill system, your boiler should maintain a pressure reading of about 12-15 psi without any work on your part. If not, add water manually - open the boiler's water feed valve until the pressure gauge reads about 12-15 psi.
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One-sentence summary -- Diagnose your radiator. Find a radiator key. Turn off your heat Open your radiator's valves. Catch drips from the valve. Wait for water to squirt out of the bleed valve. Repeat this process on all the radiators in your house. Check your boiler's pressure level.


Its app icon resembles a red, yellow, green, and blue sphere. It's in the upper-right corner of the window. A drop-down menu will appear. You'll find this near the bottom of the drop-down menu. It's at the very bottom of the page. Clicking Advanced expands the Settings page to include more options. It's near the bottom of the "Privacy and security" section. You'll find this near the bottom of the menu. It's near the top of the menu. Clicking it will turn it grey {"smallUrl":"https:\/\/www.wikihow.com\/images\/d\/d5\/Android7switchoff.png","bigUrl":"\/images\/thumb\/d\/d5\/Android7switchoff.png\/35px-Android7switchoff.png","smallWidth":460,"smallHeight":394,"bigWidth":"35","bigHeight":"30","licensing":"<div class=\"mw-parser-output\"><p>I edited this screenshot of an Android icon.\n<\/p><p>License: <a rel=\"nofollow\" class=\"external text\" href=\"http:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a><br>\n<\/p><\/div>"}. Chrome will now block the majority of web page pop-up ads.  If this switch is grey, Chrome is already blocking pop-ups. You can block pop-ups from individual sites by clicking Add under the "Blocked" section of the menu and entering the URL of the site from which you wish to block the content. To allow pop-ups from specific sites, click on Allow and enter the URL from the site(s) from which you'd like to see pop-ups.
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One-sentence summary --
Open Google Chrome . Click ⋮. Click Settings. Scroll down and click Advanced. Scroll down and click Content Settings…. Scroll down and click Popups. Click the blue "Allowed" switch .