What to know about Central Heating Radiators
When central heating systems are discussed, the focus is mainly on the boiler and the source of heat. The importance of central heating radiators is usually understated even though they are a key part of the heating system. You must know what they do and how to maintain them.
Central Heating Radiators
Radiators are the main source of heat in most homes that have central heating. They are responsible for heating the air in each room up to an optimal temperature. The function of the radiator is to transfer heat from the central boiler system into your home's air via water pipes. They come in many different styles and forms, but their basic principle remains the same - transfer heat from one place to another.
Central heating radiators can either be attached to the floor or wall. They are usually fitted with valves that allow you to control the heat in each room individually using a central thermostat. The valves are controlled via metal levers on top of them, which you turn left or right depending on whether you want warmer or colder room temperatures.
How do Central Heating Radiator work?
A radiator transfers heat utilizing convection (hot air rising) and conduction (heat passing through solid objects), into the air that surrounds it.
The radiator is connected to a water supply and when this is turned on, the hot water in the radiator boils and moves out of it into the surrounding area. The surrounding air is heated and spreads out across the room via convection currents (the hotter the room, the faster the heat will be lost). This heats the air in the room causing an even temperature throughout.
Types of central heating radiators
There are several types of central heating radiators, including panel radiators, column radiators and towel radiators. These all have their own benefits depending on the size, shape and flow rates of the room.
What are the advantages of central heating radiators?
Central heating is the most popular way of distributing heat around a property in almost every country.
There are many reasons why central heating radiators may be preferable over other forms of heating, or other central heating systems.
What are the disadvantages of central heating radiators?
Common faults with radiators
Leaking radiators are one of the most common problems with central heating systems. If your radiator is leaking, it needs to be replaced as soon as possible, especially if you have children at home, since the water could burn them.
Another problem that may arise is having no heat, or rather very little. This usually happens when the radiator thermostat settings are set too low. This can be solved by opening up the radiator valve and, using a spanner, adjusting to the desired temperature setting. If enough heat isn't getting around the house then turn up all the radiators a few degrees.
If you have radiators in very big rooms, for example, hallways or large bedrooms, it is not necessary to turn them on their full temperature settings since no person is occupying the whole space heated by the radiator. In this case, try turning down your radiator's setting and increase gradually until you feel the area is comfortable.
Some radiators are noisy and make a banging, rattling or hissing noise. This is normal and not to be worried about. If the radiator is making too much noise it can probably be tightened with two screws on each side which can easily be turned using a regular screwdriver.
How to balance central heating radiators
Central heating radiators are balanced with a balancing valve which is usually located on the other side of the radiator behind it. The valve consists of two knobs and if one turns them in one direction it opens up the air inside the radiator thus making it heat up faster than normal. If the knob is turned in the other direction it releases air from inside the radiator making it heat up slower which should be done for the valves that are closer to the boiler.
What causes a radiator valve to leak?
If a radiator valve starts leaking then this indicates an issue with either one of its components being defective or there are broken pipes somewhere in the top of the heating system.
Banging radiators when the central heating is on
This is a very common problem that happens if there has been a change in pressure throughout the heating system. When this happens, air bubbles or pockets start creating their way to the radiator and as they move through the heating system they make knocking sounds that can be heard from any of its radiators.
What would cause air in central heating radiators?
The air is pumped through the system to balance the pressure in all of its pipework. Air can get trapped inside, especially if you have a badly insulated system or a radiator that has been installed too close to another one.
What should I do with a banging central heating radiator?
This issue needs to be addressed as soon as you notice it. If the air pocket is on a radiator that is not in constant use, just allow it to release naturally.
If the banging noise is being caused by trapped air, you need to seek a professional heating engineer to have your system balanced and any air pockets removed from the pipework.
What else can cause a banging radiator?
If you have a convector radiator, there are other causes. A fan can become stuck and start banging against one of the fins in the radiator. When this happens, it is best to turn off your central heating and call an engineer.
A loose or faulty cover lock can cause a loud knocking noise and needs immediate attention. A faulty bleed valve can also cause a banging sound.
How to bleed central heating radiators
A leaking or poorly-functioning radiator bleed valve can be a cause of valves banging. If your bleed valve has become stuck closed, it will need turning almost to the off position but not quite to release trapped air from the system.
If you have a traditional single radiator with a wheel adjuster, make sure this is turned fully to the open position.
If you have one of the new generation valves with a twist adjuster, turn this fully anti-clockwise.
On a wall hung radiator, make sure that the water is turned on hot and then open each radiator in your system one at a time - again making sure that the wheel bleed valve is fully open on the radiator that is furthest away from your boiler. If you have an external tank, of if you are not sure where your main stopcock is, turn on your hot water to give maximum flow through the system - again starting with one radiator at a time and opening each in turn.
If any radiators remain cold when the system is up to temperature, turn the wheel adjuster in small quarter turns in time with either hot or cold calls in your house until all radiators are delivering heat. Once you have done this make sure that your boiler is turned off and then check your oil burner to ensure it too is not running cold.