A central heating system which is out of balance will result in some radiators being hotter/colder than others. This variation is temperature is down to the distance radiators around a property are situated in relation to the boiler, with those which are furthest away likely to be noticeably colder.
Why some radiators fair better than others
Radiators operate with a wet central heating system, relying on the boiler to heat up water from you water tank and pump it through a pipe network to which radiators are connected. Each radiator is fitted to a branch of pipe leading to this network. As heated water travels to each radiator in a property, naturally those closes to the source of heat (the boiler) will benefit most from the hottest water, while those at the end of the pipe network will have cooler water and give off less heat.
Balancing heat distribution
To balance radiators correctly you need radiator thermometers to read each heater’s temperature. These can easily be bought or hired online. You also need to know how to use your radiator valves. There are two types of radiator valves, the control valve turns an individual radiator on and off and lockshield valve (which has a cover on it) is used to control how much was goes to a radiator. The cover on this valve can be removed with a pair of pliers.
First of all you need to turn off your central heating system and allow it to completely cool. Once cooled, open both valves on all radiators. Turn the heating back on and make a note of the order in which radiators heat up. Now turn the heating off again and wait for the radiators to cool. Then turn it on again and go to the first radiator in your noted heating sequence. Place a radiator thermometer at the flow and return. Turn off the lockshield valve and then slowly open it, you are aiming to achieve a difference in temperature between the two thermometers of about 20 degrees Fahrenheit / about 11 degrees Centigrade (from flow to lockshield).
Repeat this procedure across each radiator in the heating sequence order you noted.
In most cases as you go from one radiator to the next you’ll find that the lockshield valve needs to be opened more than its proceeding one, with the last being almost or fully open.
Once this process is complete for all radiators you have a fully balanced central heating system.
Author: Laura Davis