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Last updated: 15th April, 2024


Balancing Your Radiators

Balancing Your Radiators

Key takeaways

  • If radiators within your home are heating up at different rates, this is a sign they need balancing.
  • Often it's wise to 'bleed' radiators before balancing them.
  • It can be beneficial to arrange a Gas Safe registered engineer to service your boiler annually.

At iHeat we’re experts in anything relating to keeping your home heated and comfortable, this includes radiator function and problem troubleshooting.

In this blog we’re going to be exploring the act of balancing the radiators within a property, a solution to a problem that if not addressed can seriously impact your home in terms of heat wastage.

When Do My Radiators Need Balancing?

If radiators in different locations within your property are heating up at different rates, the water flowing into them from your boiler is not being dispersed evenly and the likelihood is they’ll need to be balanced. 

Unbalanced radiators aside from being incredibly stress inducing, are extremely inefficient in terms of energy loss and subsequent expenditure.

However, if your radiators have cold spots and make noises when the heating is turned on, they’ll need to be ‘bled’, before being balanced.

Bleeding a radiator is the act of releasing trapped air to ensure water is not being displaced and causing the top of the radiator to become cooler, causing their performance to degrade.

It’s wise to bleed a radiator before attempting to balance them as this will provide a more accurate heat reading.

We have a video available here for more information on bleeding your radiators.

How To Balance A Radiator

First of all to carry out the initial bleeding and balancing of your radiators you’ll need the following tools:

  • Bleed key

  • Screwdriver

  • Lockshield valve key or adjustable spanner

  • Digital thermometer or multimeter with thermometer

Step 1 - Turn off your central heating

Firstly switch off your central heating and allow radiators to cool, as mentioned it’s prudent to have already bled and if need be have carried out a system power flush.

Step 2 - Open the valves

You must fully open the thermostatic valves by turning the valve head to the highest number on the dial, this is usually anti-clockwise (to the left).

If your radiators do not have thermostatic valves, alternatively you can make sure the lockshields are open by removing the cover cap and turning the valve anti clockwise with a valve key or spanner.

Step 3 - Keep track of radiator heating rates

After all of the radiator valves are open, switch the heating back on and monitor the order the radiators heat up in.

Step 4 - Switch the central heating back off and on again

Once you’ve made notes on the heating rates, switch the heating fully off and allow radiators to cool back down, before switching the heating back on…we know, but keep soldiering on.

Step 5 - Adjust the fastest heating radiator

Turn the lockshield valve on the fastest radiator until it’s completely closed and then open it by a quarter turn.

Step 6 - Take temperature measurements

Firstly, once the fastest radiator has heated up, take an accurate temperature reading (right at the point of connection between the pipework and lockshield valve). Then take the temperature of the pipework on the opposite side, where the TRV is found and make a note of both measurements.

Turn the lockshield valve slowly until the difference between the two readings is exactly 12°C

Step 7 - Balance other radiators

Repeat step 6 on other radiators around the property in order to effectively balance them; often the further the radiator is away from the boiler, the more its lockshield valve will need to be opened to provide equal water reception, for example the slowest radiator to heat up may require its lockshield valve being fully opened.

Radiators Still Not Balanced?

If you have thoroughly carried out all the steps in the process as listed above, yet are still having issues, equal water dispersion disparities may be down to other problems.

One prevalent component issue that can lead to radiator imbalance is a faulty pump that isn’t efficiently thrusting water around your central heating system.

Another type of underlying cause of radiators not being balanced is a build up of ‘sludge’ within the system; tell tale signs of sludge presence is thick, dark water escaping from radiators when they’re bled, or cold spots at the bottom of the radiator.

To remedy this issue a system cleanse may need to be carried out via a power flush if one has not been carried out prior to carrying out steps 1-7.

Arrange A Boiler Service

It can be beneficial to have your boiler serviced by a Gas Safe registered engineer every 12 months or if you notice a decrease in its performance.

The Gas Safe Register is the appointed representative of the safety regulatory group- Health and Safety Executive. 

All registered gas safe engineers should carry and be able to present official accreditation and have a verified and unique ID number. 

All of our iHeat engineers are registered Gas Safe!

Get A New Boiler With iHeat

If your old, inefficient boiler is succumbing to natural wear and tear, it could be the time to replace it with a sleek, efficient modern boiler from our expansive collection here at iHeat.

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Frequently Asked Questions

What is the Quickest Way to Balance Your Radiators?

Balancing your radiators efficiently involves adjusting the flow of water through each radiator so that they all heat up at the same rate. Here's a quick guide to do it:
Turn Off the Heating: Start with your heating system turned off and allow all radiators to cool down.
Open All Valves: Fully open the lockshield and TRV (thermostatic radiator valve) on all radiators.
Turn Heating Back On: Once the system is on, go to the radiator closest to the boiler and slightly close the lockshield valve until it warms up evenly.
Adjust Each Radiator: Move to the next radiator further away from the boiler, slightly closing the lockshield valve more than the previous one until all radiators warm up at a similar rate.
Use a Thermometer: It helps to use a digital thermometer to check the temperature at the inlet and outlet of each radiator. Aim for a temperature difference of about 12 degrees Celsius between the two.
This process might take a couple of attempts to get perfect but can be done relatively quickly with practice.

How Do I Know if My Radiators Need Balancing?

You might need to balance your radiators if you notice:
Uneven Heating: Some radiators are hot while others are lukewarm or cold.
Slow Heating: Some radiators take much longer to heat up than others.
Noise: Noisy radiators can also be a sign of unbalanced flow.

Do I Need a Plumber to Balance My Radiators?

While you can balance the radiators yourself using the steps outlined above, hiring a plumber or a heating engineer might be preferable if you're uncomfortable with the task, or if your heating system has ongoing issues that simple balancing doesn't resolve.

Why Do We Need 12 Degrees When Balancing Radiators?

A 12-degree Celsius difference between the flow (entry point) and return (exit point) temperatures in each radiator is typically aimed for to ensure that each radiator is efficiently contributing to heating the space. This temperature difference indicates that the radiator is effectively extracting heat from the water flowing through it.

What Happens if Radiators Are Not Balanced?

If radiators are not balanced, the system may not heat your home evenly or efficiently. Some rooms may be too hot or too cold, which can lead to increased energy usage and higher heating bills. It can also cause strain on the boiler and circulation pump as they work harder to heat the space, potentially leading to premature wear.

How Long Does It Take to Rebalance Radiators?

The time it takes to rebalance radiators can vary depending on the size of your home and the number of radiators. Generally, it might take a few hours to adjust all radiators properly, especially if you are doing it for the first time. The process involves adjusting and waiting for changes in temperature, which can be time-consuming.

Stephen Day profile photo
Article by
Stephen Day | Co-founder
Gas Safe registered and FGAS certified engineer with over 20 years experience in the heating and cooling industry.