Easy Steps On How To Change A Radiator Valve On Your Own

The temperature has dropped outside, and it’s time to turn on your home’s radiators, but the room isn’t getting any warmer? After a while of fiddling around, you realise that your valves have stopped working and you need to replace them. The only problem is, you don’t know how to change a radiator valve!

tools for replacing radiator heating valve

Some people like electric heaters, electric or oil filled radiators, while others prefer the traditional and powerful ones. And although they are small, these valves play a significant role in the performance level of your central heating system! Fitting a new valve onto a heated towel rail or radiator isn’t as difficult as you might think; it is almost as easy as fixing a small leak. This article offers a handy how-to guide to change your radiator valves and make your home warmer. Oh! And while you’re at it, think about all the energy you can save and how much you can lower your bills. Cool, right?

Why replace a valve in your radiator?

Before you start with your DIY project to change your valves, you should understand why you might need to do so in the first place. You’ll see that there are many reasons as to why your radiator may need its valves replacing, from looks to efficiency.

Your current valve is faulty

As with all home appliances, when they aren’t functioning correctly, you probably need to replace them. These valves are an essential part of how your radiator operates because they control its heat. Valves adjust the water amount entering and exiting either side of the radiator. That way, they balance the heating system and allow you to change the radiator’s temperature with ease.

Suppose one, or both, of your valves, is faulty. In that case, it will not only affect your radiator’s performance by not allowing it to heat up and cool down effectively, but you’ll also end up spending more money on heating at the end of the day. 

Swapping valve types

When you want to switch from manual valves to a thermostatic valve, you’ll need to change your current ones. The best thing about a thermostatic valve is that once it achieves the set temperature, the valve will automatically stop the water flow into the radiator, maintaining the temperature you want.

Updating your radiator’s look

Classic valves aren’t always the best looking option for your rad. The good news is there is a whole range of smart and stylish valves on the market to finish your heating system perfectly. You can choose from a range of different colour options to specific styles and designs. It’s for sure that you’ll find a valve to suit the look you’re opting for.

Woman's hands adjusting thermostat on heating radiator valve

What to consider before changing your valve

Before changing a valve, there are some things to keep in mind.

  1. You should ensure that your new valve will fit onto your existing piping. If it doesn’t, and the pipes need replacing too, you should better consider getting a professional in to do the job.
  2. If your system is regular, with a small F&E conventional cylinder tank in the loft, then again, it’s best to get a professional to replace your valves.

How does a valve in the radiator work?

There are 2 common types of valves; manual and thermostatic valves. The first ones require human interaction when changing the temperature settings, while the others regulate the temperature themselves. Let’s find out a bit more about them!

Manual valves

A manual radiator valve works just like a tap would; you turn it up by hand, and it works by altering the hot water flow travelling from the boiler into your radiator. The higher the setting is, the higher the hot water volume that enters the radiator producing greater heat output. When it reaches the desired temperature, you’ll need to go to the radiator and change the temperature setting for a cooler or warmer temperature. 

Thermostatic radiator valves

Thermostatic valves, also known as TRV, feature a temperature sensor. This smart sensor switches off the heating automatically when the desired temperature is reached and then turns it back on when the temperature dips. That way, it ensures a constant and much more accurate temperature

There are 2 types of TRV; the spring version and another one with a wax jacket and works in a similar way. The spring one works by monitoring the room’s temperature the following way. When your room is hot, the metal spring expands and plugs the gap from where the water comes through. When the radiator doesn’t have a steady flow of hot water and cools down the metal spring contracts and reopens the sealed gap causing the flow of hot water to commence. You now can tell that a thermostatic valve can save you quite a lot of money each year in heating bills!

Close up of a hand turning a radiator knob either up or down

Step-by-step guide: How to change a radiator valve

You are now ready to start with your DIY project! Follow these simple steps to change your radiator valve and achieve a safe and effective result.

What you’ll need

Either you are changing your valves or replacing a manual valve with a new TRV, you should prepare the right tools and equipment you may need to carry out the task. Here’s a list for you:

  • New TRV valve
  • Adjustable spanner/pliers
  • Radiator bleed key
  • Wrench
  • Hose
  • PTFE tape 
  • A jubilee clip
  • Wire wool
  • A dry cloth/towels/old sheets

Step 1: Turn off the central heating system and the water supply

For your safety, the first thing you need to do is switch off all thermal systems

  1. Get rid of the cap from the top of the valve body that protects the return valve and find some pliers or an adjustable spanner
  2. Use your tool to turn the shaft clockwise until it doesn’t turn anymore. 
  3. Turn the valve on the opposite side of the radiator clockwise by hand. 
  4. Using the thermostatic valve, turn it clockwise until you see a number showing zero. That way, you will ensure that your radiator’s thermostat doesn’t pick up external temperatures and try to adjust the water heat in the radiator accordingly.
  5. Turn off the electricity to your boiler. It’s essential not to skip this step as some combi boilers habitually switch themselves back on, even after you power them off.

Step 2: Prepare your home and get the valves ready

Gather all the equipment you’ll need, including the valve, and get ready to bleed the radiator and drain out all the water that’s in it. 

  1. Place towels or old sheets on the floor around your radiator to dry any leaking water.
  2. If you’re replacing an old TRV with a new one, take the head off the 2 units by hand. Remove connectors and nuts on the new valve and coat the parts that join the radiator.
  3. Wrap some PTFE tape to the radiator tail and fit this to the radiator.  For the best result, wrap it around clockwise multiple times.

close up to hand holding tool to replace radiator valve

Step 3: Bleed the radiator and drain out any water

In this step, you’ll need to use the hose

  1. Connect the end of the hose to the drain cock and run it outside to bleed the radiator and drain out any water
  2. Once you’ve connected it to the drain valve, release all the water in the radiator. Use the radiator bleed key to bleed it and ensure that it’s filled up with air. You’ll need approximately 15 minutes in total for this step.

Step 4: Remove the old valve

It’s now time to fit your valve, taking off the old one.

  1. Unscrew the cap nut of the pipework and remove the valve
  2. Hold the old valve’s body with a pair of grips or a wrench while you use an adjustable spanner to unscrew the nuts and slacken off the lockshield valve.
  3. Unscrew the nuts and take off the body of the valve from the radiator. 
  4. Using wire wool, clean away any excess gunk on it.

Step 5: Fit your new radiator valve

  1. Position the new valve in the right place
  2. Align the sealing components and valve cap-nut over the pipe’s end and attach the valve. Be careful not to tighten the nut too early. 
  3. With your wrench, align the valve with the adaptor and tighten the cap-nut that joins them together. 
  4. Make sure you’ve tightened the cap-nut that holds the valve to the water pipe. You can fit the TRV onto the valve manually.

Step 6: Turn on the water supply and bleed the radiator again

You have now installed your new radiator valve successfully, and you’re ready to have a more aesthetically pleasing and cooler or warmer home. Turn on the supply of the water and bleed your radiator once again. Opening the bleed valves is necessary as it releases all trapped air and enables a better and smoother water flow within the radiator. 

To complete this step, follow the guidelines already mentioned in Step 3. You’ll also need to fill the system with water again, which involves switching back on the heating and water supply

man adjusting heat in radiator valve

Step 7: Re-pressurise the system and check for any faults

You need to re-pressurise your whole system and double-check for any defects. Repressurising your boiler may include ineffective temperature control, leakages, or other related issues.

Step 8: Clean when the job is done

Before you thoroughly enjoy your new radiator valve, pack away all the equipment and clean the radiator and the area around. You should wipe down any drips and spills and clean and vacuum the overall area to be neat. You are now ready to enjoy the fruits of your labour!

Extra tips for fitting valves

Do you want to make sure you’ll get the job done right? Here are 6 extra tips to help you out:

  1. The pipe jointing compound you’ll use needs to be designed for water, not gas.
  2. Make sure to double-check if the radiator bleeds are open or closed.
  3. Always have a towel down to catch any drips while working.
  4. Be prepared for your system to spill water even when you think you’ve fully drained it.
  5. You can attach thermostatic valves to either side of a radiator. You should place them where there is easy access and good airflow to accurately measure room temperature.
  6. When bleeding and refilling your system, we’d recommend adding an inhibitor to keep your radiators working at their best.

How much does it cost to replace a radiator valve

A registered heating engineer or an experienced plumber will charge between £75 and £100 plus the cost of the thermostatic radiator valve<span style=”font-weight: 400;”>. If you change your old radiator valves yourself, the price will be much lower; all you will need to purchase is a valve that will cost between £10 and £40.

close up to female hand putting money in pig money box standing on a radiator
Your radiator should now be working perfectly! If you replaced your valve because the old one was worn or outdated, then we are sure you’ll be pleased with your new, shiny one. Please note that since each system is different, you should always consult an expert if you’re ever in doubt. For the best result, follow our instructions and remember; a house is a home when you keep it warm and filled with love! And when you’re done, you can dress your radiator covers to look good.

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