How to Isolate a Radiator

Are you looking for tips on how to isolate a radiator?

Perhaps you're planning on removing a radiator, or moving it to a different room, and need to know how to isolate it first. You may also be wondering whether isolating a radiator is the right way to reduce heating in a room that you rarely use.

This guide will tell you everything you need to know about isolating a radiator, including a step-by-step guide on different radiator isolating methods.

Let's start!

What Tools Do I Need to Isolate a Radiator?

Below is a list of the tools you'll need to isolate a radiator:

• Screwdriver for removing a lockshield valve cap.
• 6mm Allen key or lockshield valve key.
• Adjustable spanner for some types of lockshield valve.
• Old towels and a container to catch any water.

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What Safety Equipment Do I Need When Isolating a Radiator?

You do not usually need any specialist safety equipment to isolate a radiator. However, make sure the heating is switched off and the radiator has cooled down before you start.

If the radiator is being left in place, the heating can be turned back on once both valves are closed. The isolated radiator will stay cold while the rest of the system continues to work normally.

If you plan on bleeding your radiator or isolating and removing a radiator, you may want to wear overalls or old clothes, as dirty water can leak out.

You may also want to have a container handy to catch any water that may leak from the radiator.

What Materials Do I Need to Isolate a Radiator?

You won't need any additional materials to isolate a radiator, as it's done using the existing components on the radiator.

How to Prepare for Isolating a Radiator

When preparing to isolate a radiator, you should start by inspecting your radiator to determine the type of valves attached to it.

This will help you determine which tools you'll need for the job, as different valves require different isolating methods:

• Radiators with standard turn valves, or thermostatic radiator valves (TRVs), can be turned by hand.
• Radiators with lockshield valves may need a screwdriver to remove the cap and a 6mm Allen key, lockshield valve key or adjustable spanner to close the spindle.

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How to Isolate a Radiator Yourself

There are several methods to isolate a radiator.

You should inspect your radiator valves first to determine which method you'll need to use:

Isolating a Radiator with a Turn Valve

If your radiator has a standard turn valve, then the method of isolating is quite simple.

Turn the valve clockwise as far as it will go, as this stops hot water entering through that valve. The radiator will remain connected to the heating system at the other end. To isolate it fully, close the lockshield valve on the opposite side by following the steps further down this page.

Radiator with Thermostatic Valve

Some radiators have a thermostatic radiator valve (TRV), which controls how warm the radiator gets.

If you have this type of radiator, turn the TRV down as far as it will go. If it has a snowflake setting, continue turning the valve past the snowflake to 0. You may feel slight resistance as it reaches the fully closed position.

Closing the TRV alone does not fully isolate the radiator, so make sure you also close the lockshield valve at the opposite end using the steps below.

Radiator with Lockshield Valve

Step 1

A lockshield valve can be easily identified by hand as it won't turn. Instead, the top of the valve should pull off. This part can usually be done by hand. However, sometimes you may need to undo it with a screwdriver.

Step 2

Remove the cap to reveal the brass spindle underneath.

Step 3

Turn the spindle clockwise with a 6mm Allen key until it is fully closed. Some lockshield valves may need a lockshield key or adjustable spanner instead.

To isolate the radiator completely, make sure the valve at the other end is also turned off.

Why Would I Need to Isolate a Radiator?

There are several reasons why you may want to isolate your radiator:

• The Radiator Is Leaking — Isolating a leaking radiator will stop the flow of water, minimising the damage the leak can have on your floors.
• You Want to Remove a Radiator — If you plan to remove your radiator, you will need to isolate it first. A radiator is connected to a complete system that circulates water. If you remove one of the radiators in your system without isolating it first, then the entire water contents from your system will end up being emptied out onto your floor.
• You Want to Reduce Heating in an Unused Room — Some homeowners want to isolate a radiator in an unused room, but this is not recommended. Turning the radiator down can help reduce energy use, but it is best not to leave the room completely unheated. If the radiator has a TRV, use the snowflake setting to keep a small amount of heat in the room and help reduce the risk of condensation and mould.

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