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How to Bleed Underfloor Heating

A homeowner using GLP’s easy guide on how to bleed underfloor heating to release trapped air from their manifold.

Underfloor heating systems are popular for their efficiency and comfort. However, like any heating system, they need regular maintenance to perform at their best. One important task is bleeding the system to remove air trapped in the pipes, otherwise, it might feel like your underfloor heating is not working or not hot enough. This guide on how to bleed your underfloor heating system will help you understand and perform the process, whether it’s a WarmUp, Uponor, or Polypipe system.

Understanding Wet System Underfloor Heating Systems

Wet System Underfloor heating (UFH) systems consist of a network of pipes laid under the floor, distributing warm water to heat the space above. If you have noticed that your underfloor heating has stopped working, is not heating your home or workspace evenly or has become inefficient, it may be that air in the pipes is to blame. Bleeding the system helps to remove this air, ensuring optimal performance and comfort.

Tools and Materials Needed to Bleed Your Underfloor Heating System

Before starting, gather the following tools and materials:

  • Screwdriver or bleed key (specific to your system)
  • A bucket or towel to catch water
  • Pressure gauge (often integrated into the system)
  • Replacement water, if necessary

Preparation Steps

  • Turn off the heating system: ensure the system is turned off and has had time to cool down completely. This is a must for safety and effective bleeding. If you skip this step, you risk burning yourself and other injuries. It’s also a good idea to wear gloves and safety glasses to protect yourself from hot water or sharp parts.
  • Locate the manifold and bleed valves: The manifold is the central hub of your underfloor heating. It is usually found in a central location and connects all the underfloor heating loops. The bleed valves are typically situated on or near the manifold.
  • Check system pressure: use a pressure gauge to check the system’s current pressure. It should be within the manufacturer’s recommended range. If it’s too low, you may need to add water later.

Bleeding Underfloor Heating: Step-by-Step Guide

  1. Locating and opening the bleed valves:
  • Find the bleed valves on your system. Heatmiser, Uponor, or Polypipe systems, are typically located on the manifold.
  • Place a bucket or towel under the valve to catch any water.
  • Open the valve carefully with a screwdriver or bleed key. As air escapes, you should hear a hissing sound.
  1. Bleeding each loop individually:
  • Open each valve one by one, starting with the first loop and moving through each in sequence.
  • Allow the air to escape until water starts to flow steadily, indicating that all air has been expelled.
  • Close the valve once only water is coming out.
  1. Checking and adjusting system pressure:
  • After bleeding each loop, check the system pressure using the pressure gauge.
  • If the pressure is low, refill the system with water until it reaches the recommended level. Your system’s manual provides specific instructions on how to do this.
  1. Closing the bleed valves and restarting the system:
  • Ensure all bleed valves are securely closed.
  • Gradually restart your heating system and check for any irregularities in heating or unusual noises, which might indicate that further bleeding is necessary.

Common Issues and Troubleshooting Tips

If you find that air is still present after bleeding your underfloor heating system, don’t worry. It’s common for some air to remain trapped initially. You might notice gurgling or knocking sounds – this is a clear indicator of trapped air in your underfloor heating system. 

Repeat the bleeding process to dislodge air and improve the heat flow. Ensure you methodically go through each loop, as trapped air in any part of the system can affect overall performance. Thoroughly bleeding all loops should resolve this issue.

Maintaining the correct pressure in your system is important for its efficient operation. If you’re unable to keep the pressure at the recommended level, it could indicate a leak somewhere in the system. Low pressure can compromise heating efficiency and may lead to further issues. In such cases, it’s best to seek professional help. Our friendly and experienced team are available to provide expert advice and support to identify and fix any leaks in your system.

Maintenance Tips for Underfloor Heating Systems

At a time when energy bills are already high enough, no one needs underfloor heating problems or for it to run inefficiently. With a little care, your home or commercial UF heating system will keep you warm and cosy. Regularly bleeding your system, particularly at the start and end of the heating season, prevents air buildup and allows your system to work optimally.

We recommend that you regularly do a visual check for leaks and monitor the manifold so you can be confident that the pressure remains within the recommended range. This could be a monthly task you do alongside submitting metre readings or paying your energy bills. By building this into your routine, you’re more likely to do it! It’s a good idea to keep an eye on the pressure, as a drop in pressure could mean there are underlying issues which require help from an underfloor heating expert.

Schedule an annual service to keep your underfloor heating in top condition. Regular servicing ensures longevity and efficiency. Our technicians will inspect the system, check the pressure, and address any issues. We’ll examine all components for wear and advise on repairs or replacements. This proactive approach prevents major problems, ensuring smooth operation year-round. Regular maintenance extends the system’s life and ensures peak efficiency for consistent, comfortable heating.

Let GLP Take Care Of Your Underfloor Heating System

Finding time to bleed the underfloor heating system probably isn’t top of your to-do list, but it is essential for maintaining its efficiency and comfort. At the start and end of winter, whether you have a Warmup, Uponor, or Polypipe system, air bleeding will allow your UFH heating system to work at its best and keep your home or business comfortably heated.

If you are concerned about performing regular maintenance safely or you have persistent issues, contact us at GLP, and we’ll get your system running smoothly.

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