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What is a control radiator?

By: Nikola BelavicUpdated: April 04, 2021


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    May 21, 2022
Each radiator in your home needs a pair of radiator valves which act like taps, enabling you to control how much heat they give out. One of the valves controls the amount of hot water entering the radiator and the other (known as the lockshield valve) balances the system by controlling how much heat the radiator emits.

In this regard, how does a radiator valve work?

How do Thermostatic Radiator Valves Work? The TRV is a valve that self-regulates, meaning it adjusts the flow of water into your radiator depending on the setting. And as the room temperature changes, the valve head expands, adjusting a pin in the valve body so that it opens or closes.

Also, how do I adjust my radiator?

  1. Locate the main boiler for the radiators.
  2. Turn the boiler thermostat up to a higher temperature.
  3. Adjust the temperatures on the individual radiators by turning the wheel valves counterclockwise to raise the temperature, or clockwise to lower the temperature.

What do the numbers mean on a radiator thermostat?

The numbers on a thermostatic radiator valve refer to the temperature in the room, not the radiator. This is a common misconception, so don't worry if you weren't aware of this before. If the room is cold, the the TRV will allow more hot water into the room to heat it up.

What number should your radiator be on?

Radiator valves will have numbers or symbols representing how much heat the radiator is currently giving out represented by a level between 1 – 6. Generally speaking, turning the valve to number 3 should result in a room temperature of around 20°C with each number above / below representing a degree.


What temperature should I set my radiator to?

To maximise efficiency, we recommend setting your radiator dial to 75 degrees and your hot water to 60 degrees. Once you've got your boiler running at the optimal temperature, you'll want to set the timer for when you need heating the most.

What is the difference between a lockshield and radiator valve?

Manual and Thermostatic Radiator Valves
Manual radiator valves are simple radiator valves opened and closed by hand. Typically they come in pairs, one wheelhead valve and one lockshield valve, fitted to opposite ends of the radiator. Again, the only difference between these two manual valves is the cap.

What are the 2 valves on a radiator?

Radiators typically have two valves located on the pipes that allow hot water to enter them. The main one, which more people are familiar with (often called a 'control valve'), is used for turning on and off your radiator in normal use. The second is your lockshield valve.

What is a radiator lockshield?

The lockshield valve is the valve on a radiator that is usually covered with a plastic cap. The term “lockshield” means that once adjusted, the valve is shielded with the plastic cap that prevents it from being accidentally changed.

Should radiator valves be fully open?

As you progress further away from the boiler, the Lockshield valve will need to open slightly more. It's not uncommon for the Lockshield Valve in the first radiator to be open around one-quarter of a turn, while on the last radiator, it may need to be fully open.

How do you bleed a radiator?

Summary: How to Bleed a Radiator in 10 Easy Steps
  1. Turn on the central heating.
  2. Feel all the radiators in your home.
  3. Switch off the heating.
  4. Wait for the radiators to cool completely.
  5. Grab your supplies.
  6. Find the bleed valve.
  7. Loosen the bleed screw.
  8. Wait for the hissing to stop completely.

Do radiator thermostats save money?

Thermostatic radiator valves do not control the boiler; they reduce the flow of water through the radiator which they are fitted to when the temperature goes above a certain setting. Set them to the level you want for the room; a lower setting uses less energy and so will save you money.

Why is my radiator not heating up?

Make sure there is no air in the radiator. Using a radiator key and a cloth, release any air trapped in the radiator. Remember to top the heating system up with water should it be a pressurised (sealed) system. Always remember to check the lockshield valve on the radiator is open and that the TRV pin is not stuck down.

What side is the flow on a radiator?

Bit late after attached radiator cos need to make sure I get the TRV on right side first time. With the heating on you should still be able to touch the pipes under the valves. Normally (but not necessarily!) the flow is on the left as you look at the rad.

How long should it take my radiators to heat up?

Check the system
  1. Fully open all radiator thermostats and run the heating at full temperature for 10-15 minutes with all radiators on.
  2. Turn the circulation pump off and wait until radiators are cool - usually 30-60 minutes.
  3. Bleed the radiator nearest the boiler using a bleed key or screwdriver until water comes out.

Are smart radiator valves worth it?

Electronic/smart TRVs are also worth considering, as part of a smart heating system. This way, you can control each separate radiator from an app on your phone, even if you're away from home. Installing TRVs is an easy and relatively cheap change which can decrease bills and increase the thermal comfort of your home.

How do you control radiator heat?

  1. Ensure that the radiator boiler is on and operating.
  2. Find the wheel valve. This is located at the side of the radiator where the hot water enters.
  3. Open the wheel valve by turning it counterclockwise to provide more heat. To lessen the heat, shut down the valve by turning it clockwise.

Do radiator thermostats work?

How do Thermostatic Radiator Valves Work? The thermostatic valve head goes on top of the valve body. And as the room temperature changes, the valve head expands, adjusting a pin in the valve body so that it opens or closes. Expansion as the room heats blocks the valve body to receive less hot water into the radiator.

How long does it take to balance radiators?

The powerflush process should only take about a day to complete (usually between six and ten hours) depending on the age of your heating system, the number of radiators, and the amount of sludge and debris build-up.

How can I balance my radiator without a thermometer?

Take note of any radiators that the hot water comes in on the end with the balancing valve. For each radiator, remove the cap at the end opposite to the on/off knob and carefully fully open up the valve, anti-clockwise like a tap. Some caps require a Philips screwdriver to remove, while others simply pull off.

Why would a radiator be hot at the top and cold at the bottom?

Why Your Radiator is Cold at the Bottom, But Hot at the Top
Radiators become cold at the bottom when there is something stopping the flow of water. When the radiator is cold at the bottom this usually means that there is a build-up of something called central heating sludge which has settled at the bottom.