How to balance radiators

When to balance radiators

Unbalanced radiators don’t heat up at the same speed as each other, making some areas of your house colder than others. It means the hot water flowing from your boiler is not being distributed evenly and it can become an issue during these freezing winter nights when you need heat, like, NOW.

Balance or bleed?

If you find that some of your radiators are showing cold spots in certain patches across their surface, you’ll need to bleed them first. Here’s our full guide on how to bleed a radiator.

When you balance radiators, you’re allowing more water to flow to the colder radiators in your home, restricting the flow from radiators which are too hot. If some rooms are colder than others, it may mean that some radiators are heating up faster than others.

So if your radiators aren’t working properly and you’re not sure whether to bleed or balance them, do both. Let’s sort out the problem for you.

Tools you’ll need

• Radiator bleed key
• Lockshield valve key or adjustable spanner
• Screwdriver
• Digital thermometer/multimeter with thermometer

Get cosy with your radiator valves!

You need to know the three main types to fix this issue:

Manual valve

This is the old-fashioned type that you can use to turn your radiator on and off. It’s also called a wheelhead or control valve. It’s only got two positions – on or off – so that’s the only control you have over the amount of hot water flowing into your radiator.

Thermostatic Valve (TRVs)

Most modern radiators have a thermostatic valve instead of a manual. It looks like a dial with numbers on it

As the name implies, they have their own thermostat so that once the surrounding temperature reaches your desired level, the valve regulates the hot water flow into the radiator and only uses as much energy as needed. Keep TRVs away from your general room/house thermostat – if they’re in the same room they will interfere and compete with each other.

Lockshield valve

This is the one covered by a small domed plastic cap and it looks like you can’t really do much with it. In fact, you need to use grips of some kind to pull off the plastic cap. Some have a screw through the top of the cap that must be removed before the plastic bit can be pulled off. Underneath the cap it looks like the end of a flat-head screwdriver.

Balancing radiators: step-by-step guide

Follow these 10 steps to balance the radiators in your home:

1. Bleed your radiators

Bleed radiators that have cold spots and then check that they’re now heating up all over the surface of the radiator.

2. Turn off your central heating

Switch it off completely and allow all your radiators to cool down.

3. List all the radiators in your home

Do this on a piece of paper (or a spreadsheet if you prefer). You’ll need this later once you’ve opened all the valves.

4. Open your radiator valves

Now open BOTH radiator valves on each radiator completely, by turning them anti-clockwise (to the left). For manual valves and TRVs it’s easy to do by hand. For Lockshield valves, remove the plastic cap (instructions above) and turn the metal valve anti-clockwise with a Lockshield valve adjuster or an adjustable spanner.

5. Identify the fastest heating radiator

Turn the heating back on and walk around your house with your radiator list. This will help you find the radiator that heats up first. The most likely candidate is the one closest to your boiler. You might want to recruit your partner or kids to help you do this bit or you’ll be warming up pretty fast yourself! Now give each radiator on your list a number in order of how fast they started to heat up.

6. Turn the heating off and then on again

Once you’ve turned the heating off, check all your radiators have cooled down completely and then switch your central heating back on again. We promise you’re halfway there! – and it’s going to be worth it…

7. Turn the lockshield valve on the fastest heating radiator

Go to the fastest heating radiator on your list and turn the Lockshield valve clockwise until it’s completely closed and then open it by a quarter of a turn.

8. Take temperature readings

Once the radiator has heated up, take a temperature reading. Take the reading right at the pipework connected to the Lockshield valve, where it meets the floor or wall.

Now take the temperature of the pipework leading to the manual valve/TRV. Slowly open the Lockshield valve until the temperature reading is around a 12-degree Celsius difference from the Lockshield valve reading you took in step. Please note, this will need to be in accordance with the manufacturer’s instructions.

9. Balance is restored

Do this for the rest of your radiators and balance is restored!

How often should you balance your radiators?

Periodically check if your radiators are heating up at roughly the same rate. If not, balance again. Now you know how to do it, your boiler will be distributing heat evenly and you can look forward to an evenly heated home every morning and evening.

Some examples of when a heating system may require balancing are:

• Following the removal of radiators for decorating
• Following the replacement of radiators and valves
• Following any flushing/cleansing activities
• Following alterations to the heating system
• Following the replacement of the central heating pump
• Following the replacement of the boiler

Do you need a one-off repair to fix the cold radiators in your home? You can count on our expert repairs team to get things working again in no time.