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Radiators not getting hot? A Step by Step Guide to Bleed and Rebalance Your Radiators

This week we helped a customer in Parkstone in Poole whose bedroom radiators were taking forever to heat. After a thorough inspection, we bled the radiators and rebalanced the system, which solved the problem and got them working properly again.


Today we're here to tell you what bleeding and rebalancing your radiators is, why it matters and how you can do it too!


bedroom radiator not heating at customers in Parkstone Poole

Why Bleed and Rebalance Radiators?


Over time, air can get trapped inside your radiators, preventing them from heating up fully. This can result in cold spots or radiators that simply don’t get warm enough. Bleeding your radiators helps release trapped air, allowing hot water to flow freely.


Even after bleeding, if some rooms are still warmer than others, you might need to rebalance your radiators. Rebalancing ensures that each radiator in your home heats up at the same rate, improving efficiency and comfort.


Signs Your Radiators Need Bleeding and Rebalancing


  • Uneven room temperatures: Some rooms feel much warmer or cooler than others.

  • Cold spots on radiators: Parts of your radiator stay cold even after it’s been on for a while.

  • Slow heating: Some radiators take longer than others to warm up.

  • Noisy radiators: Gurgling or hissing sounds can be signs of trapped air.


Step-by-Step Guide to Bleeding Your Radiators


  1. Turn off your heating: Before starting, switch off your heating system and let the radiators cool down to avoid any hot water splashes.

  2. Locate the bleed valve: The bleed valve is usually at the top of your radiator. It will look like a small valve that can be opened with a radiator key, screwdriver, or in some cases, a coin.

  3. Use a radiator key: Place the radiator key into the valve and slowly turn it counter-clockwise. You’ll hear a hissing sound as trapped air escapes. Hold a cloth or small container underneath the valve to catch any water that might dribble out.

  4. Close the valve: Once water starts to flow steadily (without any air hissing), turn the valve clockwise to close it tightly.

  5. Check system pressure: After bleeding your radiators, check the pressure of your heating system. You may need to top up the water pressure via your boiler.


Step-by-Step Guide to Rebalancing Your Radiators


Once you’ve bled your radiators, if you still notice some radiators not getting hot, it’s time to rebalance your system. Here’s how:


  1. Turn off the heating and let your radiators cool down.

  2. Open all the valves: Go around each radiator and fully open both the thermostatic radiator valve (TRV) and the lockshield valve. The TRV is the dial that allows you to adjust the temperature and is usually located at one end of the radiator. The lockshield valve is typically found at the opposite end and has a simple cap that you can unscrew or a flat head screw that requires a screwdriver to adjust. Fully opening these valves ensures that each radiator gets enough hot water to heat your space effectively.

  3. Start with the nearest radiator to the boiler: Turn the lockshield valve on the closest radiator clockwise to restrict the flow of hot water slightly.

  4. Measure the temperature: Use a thermometer or touch to check when the radiator feels evenly warm from top to bottom.

  5. Work through the radiators further away: Adjust the valves on each radiator as you move farther from the boiler to ensure all radiators heat up evenly.

  6. Test the system: Turn the heating back on and monitor the radiators to make sure they’re heating at the same rate.


Benefits of Bleeding and Rebalancing Radiators


  • Improved energy efficiency: Your system won’t need to work as hard to heat your home, saving you money on energy bills.

  • Consistent home temperature: No more cold rooms or uneven heating throughout the house.

  • Prolonged system life: A well-maintained system runs smoother, reducing the risk of breakdowns or costly repairs.


Radiators Not Getting Hot and Need Help? Contact Us


If you’ve tried these steps and your radiators still aren’t heating as they should, or if you’re unsure about the process, don’t hesitate to get in touch. We provide expert plumbing services across Poole, Bournemouth, Christchurch, and the wider BH postcode area, and we’re here to help keep your heating system running smoothly.


For more info and reliable plumbing services, contact us today.


Call us on 01202 985368 or book online.


Ps why not check out some of our great reviews on our Plumberly Google page.

PPs We've recently been recommended as a Three Best Rated Plumber in Poole!






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