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How to balance your radiators – a quick & easy step-by-step guide

Have you noticed your radiators are taking a long time to warm up? Or perhaps some of them stay cold while others get nice and cosy? If your answer is a chilly ‘yes’ to either of these questions, it could be that your radiators require rebalancing.

Most are relieved to find out that the problem doesn’t lie with the boiler! Before assuming that the boiler is to blame, try rebalancing your radiators and see if the problem resolves.

Should you rebalance your radiators?

During the winter months, effectively heating our homes becomes our main priority. No one enjoys a chilly home when the temperature dips, especially when the radiators are not working properly. Aside from uneven heat distribution, unbalanced radiators can also reduce energy efficiency and thus increase energy bills.

Cause and effect

Radiators can become unbalanced if they are not correctly fitted or form sediment build-up in the system. In addition, age can be a contributing factor. Wear and tear on our radiators are extensive each year as we battle with chilly weather.

When radiators become unbalanced, the hot water from the boiler is unevenly distributed throughout the system. This uneven distribution of heat causes cold spots in the heating system and results in some radiators remaining cold or taking ages to warm up.

Balancing vs. Bleeding your radiators

Many homeowners believe balancing and bleeding radiators is the same thing. However, this is not the case. While both resolve poor radiator function, each has its own specific function. Let’s review the differences between them.

Bleeding a radiator

This process is usually focused on a single radiator that is displaying the following symptoms:

  • Noisy rattling sound
  • Trapped air
  • Cold spots at the top

If your radiator makes a loud rattling sound each time the heating is turned on and has cold spots, then it may require bleeding. For this, you will need a radiator key to expel the trapped air.

Radiators that require balancing either remain cold or become lukewarm while the rest of the system becomes fully heated. When you balance a radiator, you are evening out the flow of hot water between all the radiators connected to the central heating system.

Tools required for balancing your radiators

When balancing your radiators, you will require a few tools to get the job done:

  • Screwdriver
  • Radiator bleed key
  • Adjustable spanner
  • Digital thermometer

This can prove to be a lengthy process depending on the number of radiators you have in your home. Moreover, it is more complicated than bleeding a single radiator. However, with patience, your radiators will soon be functioning efficiently.

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How to balance your radiators

Using the tools above, you can follow the easy steps below to balance your radiators:

1. Turn off the heating

The radiators need to be cold before starting the balancing process. Therefore, if you have the heating on, turn it off and allow the radiators to cool completely.

2. Bleed the radiators

Using the radiator bleed key, expel any excess air from the radiators. This will ensure your temperature readings are accurate at the end of the process.

3. Valves

The age and model of your heating system will determine whether your radiators have a combination of the following valve types.

  • TRV Valves (Thermostatic Radiator Valve)

These valves are found on modern radiators. The valve resembles a dial and can be turned by hand.

  • Manual Control/Wheelhead Radiator Valves

Often found on older radiator models, these valves have two main positions, on or off.

  • Lockshield Radiator Valves (control valve found on most radiators)

These are located under a cover on the radiator and require an adjustable spanner or lockshield key to adjust them.

Once you have identified the valve type on your radiator, open the value fully by turning it anti-clockwise.

4. List all the radiators in the house

Use a pen and pad to note down the positions of all the radiators in your home. This will help you keep track of the order in which the radiators heat up.

5. Identify the radiators that heat the fastest

Check all the radiators are cold to the touch and ensure all the valves are open fully. Now turn the heating back on and note the order in which the radiators heat up. Tip: It’s usually the ones closest to the boiler that heat up first.

6. Turn off the heating – wait – turn it on again!

Turn off the central heating, allow the radiators to cool down completely. Once cold, turn the heating on again.

7. Start with the fastest heating radiator on your list.

Turn the radiator valves to the closed position, then open with a one-quarter turn. Stop.

8. Using the thermometer, take temperature readings

When the first radiator starts to heat up, measure the temperature in the following two areas:

  • Measure the temperature of the pipework by the lockshield valves.
  • Measure the temperature of the pipework by the TRV or manual valves.

9. Actual balancing

Use an adjustable spanner to turn the lockshield valve. This should be in a clockwise direction and needs to be done very slowly. Keep turning the lockshield valve until the difference between the temperature readings you took in step eight is exactly 12 C. Now the radiator is balanced!

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10. Balance and repeat

Moving along the list from the fastest to the slowest heating radiator, repeat this balancing process. When all the radiators have been balanced, you will notice the heat distribution has been restored throughout your home.

It didn’t work!

It can be frustrating when your radiators are still cold or lukewarm after putting in all this effort. If rebalancing the radiators has not resolved your heating woes, the problem may relate to another issue.

For example, limescale build-up or sludge may be preventing the even distribution of hot water in the system. Or perhaps your boiler requires a service or is past its prime and may need replacing.

However, before you panic and start envisioning the worst, contact a professional heating engineer to help identify the issue. Often a simple service or system flush can put your heating system back to rights!

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