Isolating a radiator might sound technical, but it’s actually a simple process that can be useful in several situations. Whether you’re dealing with a leak, planning some redecorating, or wanting to replace your radiator, knowing how to isolate it’s a valuable skill.
In this guide, we explore some common reasons for isolating a radiator and share step-by-step instructions. We’ll also teach you how to reconnect your radiator afterwards and answer some FAQs on this topic.
Ready to become a radiator whizz? Keep reading to discover:
When should (and shouldn’t) you isolate a radiator?
What you’ll need to isolate a radiator
How to isolate a radiator safely: Step-by-step guide
When to call in a JustFix professional
FAQs about isolating a radiator
When you should (or shouldn’t) isolate a radiator
There are several reasons why you might need to isolate a radiator. Here are a few of the most common:
- Replacement or removal: If you plan to replace or remove your radiator, you’ll need to isolate it and bleed it before taking it off the wall.
- Leaks: A leak can damage floors or walls and disrupt the heating system’s efficiency. Isolating the radiator stops water from flowing into it, giving you time to address the issue.
- Maintenance or repairs: If a radiator is making noise or you’re having other common central heating problems, isolating it allows you to inspect or fix it without affecting the rest of the system.
- Decorating: If you need to paint a radiator or wall or replace wallpaper behind the radiator, isolating it to cut off heat makes the process much easier.
However, isolating a radiator isn’t always the right solution. In some heating systems, particularly older ones, isolating a radiator can disrupt the heat flow to the entire home. If you’re unsure about your heating setup, it’s worth consulting a professional heating engineer before taking action.
Similarly, if you live in a rented property, it may not be your responsibility to fix radiator issues. Instead, you should notify your landlord or property manager so they can arrange for repairs.
What you’ll need to isolate a radiator
To isolate a radiator, you’ll need a few basic tools, most of which are inexpensive and can be found at any DIY store. Here are a few things you might need:
- An adjustable spanner or wrench: To turn the radiator valves
- Towels or a bucket: To catch any water that might escape
- Gloves: To protect your hands, especially if the radiator is warm
How to isolate a radiator safely: A step-by-step guide
Now that you understand when and why to isolate a radiator, let’s look at how to do it. Follow these steps carefully to isolate your radiator safely and effectively.
Step 1: Turn off the heating system
Before touching the radiator, switch off your heating system. This prevents hot water from flowing into the radiator so you don’t burn yourself whilst working. Once the heating is off, wait for the radiator to cool completely.
Step 2: Locate the valves
Radiators typically have two valves, one on each side. Usually, you’ll find the manual valve, which controls how much hot water enters the radiator, on the right-hand side.
On the opposite side will be the lockshield valve, which helps balance the heating system by controlling the flow of water out of the radiator. Make sure you can see and access both valves.
Step 3: Close the manual valve
Turn the manual valve clockwise until fully closed using your adjustable spanner or wrench. This stops water from entering the radiator. Be firm but careful, as forcing the valve too hard can damage it.
Step 4: Close the lockshield valve
Next, close the lockshield valve. Like the manual valve, it needs to be turned clockwise until tight. If you plan to reopen the radiator later, count the number of turns it takes to close the lockshield valve. This will help you reset it to the correct position when you’re ready to reconnect it.
Step 5: Turn on your heating
Turn the heating back on to check if you’ve successfully isolated your radiator. The other radiators should heat up, whilst your isolated radiator should remain cold.
Step 6: Carry out works
Your radiator is now isolated. If you’re waiting for a plumber or heating engineer to carry out work, this is all you need to do.
If you need to fix a leaking radiator, bleed a radiator, or paint around it, now’s the time! However, if you’re planning on removing or replacing the isolated radiator, make sure to drain it first.
How to reconnect a radiator
After you’ve fixed a leak or painted the area, you’ll probably want to reconnect your radiator to the central heating system. Here’s how to do it:
Step 1: Open the lockshield valve
Using a spanner, turn the valve anti-clockwise to open it slightly. If you counted the number of turns when you closed it, use the same number to return it to its original position. This ensures the heating system remains balanced.
Step 2: Open the manual valve
Next, open the manual valve (usually on the right-hand side) by turning it anti-clockwise. This allows hot water to flow back into the radiator. Open it fully to ensure the radiator heats evenly.
Step 3: Test the heating
Turn your heating system back on and check if the radiator warms up. If the radiator heats up evenly and no water is escaping, the radiator has been successfully reconnected.
When to call in a JustFix professional
Isolating a radiator is usually straightforward. However, there are times when it’s best to leave it to the pros.
If either of the valves is stuck or broken, attempting to force them can cause more damage. Similarly, if you’ve followed the above steps and your radiator still warms up, you may need to contact a qualified tradesperson. They’ll have the tools and expertise to isolate your radiator swiftly and safely.
If you don’t feel confident isolating the radiator by yourself, don’t hesitate to call for help. It's better to let a professional do the job safely and correctly than to risk damaging your heating system.
With JustFix, it’s easy to find and book a local heating and gas engineer! Simply download our app or use our website to share a few details, and we’ll connect you with a qualified tradesperson in your local area. We offer fixed hourly rates and a 12-month workmanship guarantee, so you can be sure of no nasty surprises down the line.
FAQs about isolating a radiator
Will isolating a radiator stop it from leaking?
Isolating a radiator can help reduce or stop a leak, depending on the severity of the issue. When you isolate a radiator you cut off the water supply, which can stop water from leaking.
However, isolating the radiator won’t remove the water inside, so some leaking might continue until the radiator is drained. For a complete fix, you’ll need to repair the source of the leak, whether it’s a valve, a pipe connection, or the radiator itself.
Can isolating a radiator save you money?
Sometimes. If you’re isolating a radiator because it’s not being used, closing the valves will prevent hot water from flowing into it, meaning your boiler doesn’t have to work as hard to heat it. This can reduce your energy usage and save you money.
However, isolating too many radiators in a central heating system can make your boiler less efficient. Boilers are designed to heat a certain volume of water, so reducing the system’s capacity too much might cause it to cycle on and off more frequently and use more energy.
Can you turn off multiple radiators at once?
You can turn off multiple radiators at once by isolating each one individually. That said, be cautious about turning off too many radiators and consult a heating engineer first. Isolating several radiators can disrupt the balance of your heating system, leading to uneven heating in the remaining radiators or making your boiler work inefficiently.
