QA

Quick Answer: How Does A Central Heating Radiator Work

Radiators work through a heat transfer process called convection. When water in the radiator is heated, the surrounding air is also heated up via convection and this hot air is then moved around the room as the air circulates. As the hot water flows through the system it starts to cool down.

Do both valves on a radiator need to be open?

You should open both of the valves on all of your system’s radiator when you are starting the radiator balancing process. Once this is done your radiator system should be fully balanced and your radiators should heat up evenly and efficiently.

Which way does water flow through a radiator?

Top to bottom. Hot water enters at the top of the radiator, and then the cool water exits at the bottom (where it’s fed back into the engine). Top to bottom is more efficient, since you’re not working against natural convection. Remember, a hot fluid rises, while a cold fluid sinks.

How do you control radiator heat?

You can adjust the heat by turning the thermostatic valve. Look for it on the side of the radiator. The thermostatic valve usually has a taller cap with numbers ranging from 0 to 5 on it. Adjust the dial counterclockwise to increase the heat and clockwise to reduce it.

Why do we need 12 degrees when balancing radiators?

Then on the other side of the radiator check the temperature of the pipe leading into the secondary valve or TRV. The goal is to achieve a temperature difference between the two figures of 12 degrees where the lockshield valve temperature is 12 degrees higher than the exit valve’s temperature.

Do you bleed a radiator when it is on or off?

Turn off your heating. You can’t bleed a radiator when the heating is on, as it may be too hot to touch. You could also get hot water spraying out of the radiator. Use your radiator key to turn the valve at the top of the radiator.

Can radiators flow both ways?

Most modern thermostatic radiator valves are bi-directional – so can be fitted on either the flow or return pipe of your radiator. However, it’s always best practice to fit the TRV on the flow pipe that enters your radiator.

How do you tell which is the flow and return on a radiator?

Turn off the heating until it is cool. Turn it on and aim the laser alternatively at the two tails. The one that heats fastest/first is the flow.

Do radiators have a flow direction?

Normally there is a valve on one side of the radiator, and a lock shield on the other. The valve is often the flow. If you cannot trace the pipes, the only way is to feel which pipe feeding the rad gets hot first when the boiler is first put on.

Why does one of my radiators not get hot?

If just one (or a few) of your radiators aren’t heating up, the most common reason for this is trapped air. If you’ve just turned the heating back on after the summer, air can become trapped in your radiators, causing them to be warm at the bottom but cold at the top. Your radiator should soon be nice and warm.

Do radiators turn themselves off?

These valves are fitted to individual radiators and control the temperature of the room they are in. They shut off the flow of the water to the radiator when the desired temperature is reached. It’s not a good idea to turn them fully ‘ON’ or fully ‘OFF’ to make the room warmer or cooler as this will waste fuel.

What setting should radiators be on?

Typically, the common rule for radiator temperature control is to aim to have each room somewhere between 18C (64F) and 21C (70F). In most homes, these central heating settings should be comfortable, and for others, only slight adjustments would normally need to be made to achieve a preferable temperature.

What temperature is 3 on a radiator?

Approximate conversion into degrees Celsius Valve position Reference temperature Recommended setting for 2-3 18°C Bedroom 3 19-20°C Kitchen 3-4 20-21°C Lounge, child’s bedroom 4 22°C Bathroom.

Why is 1 radiator in my house cold?

Why is one radiator cold when the heating is on? One cold radiator usually indicates that either there is air in the system or there is a stuck valve within that radiator. To check if the valve is stuck, you can remove the rotatable head on the TRV to reveal a raised pin beneath it.

What is the easiest way to balance radiators?

How To Balance Radiators Turn off your heating. Open all radiator valves. Note the speed each radiator heats up. Allow your heating to cool down. Turn your heating back on. Adjust the fastest radiator. Repeat for other radiators.

What happens when you bleed a radiator and no water comes out?

If no water or air comes out when you bleed the radiator, then the valve could be blocked with paint. Insert the radiator key into the bleed valve and slowly turn it anti-clockwise (a quarter of a turn should be enough). You should hear a hissing sound as the air escapes.

What happens if you let too much water out of a radiator?

Baird warns that letting out too much water is likely to introduce fresh water into the system, which can make the situation worse as fresh water contains a lot of air. He adds: “Some people also think if a radiator is cold on the bottom but hot at the top then it needs to be bled.

Why are radiators cold at the bottom?

Why Is My Radiator Cold At The Bottom? A radiator that is cold at the bottom is usually caused by a build up of sludge in the system. As the sludge is heavier than water, it settles at the bottom which prevents water and heat flow to the bottom of the radiator.