This is a common fault with two very common causes:
- There is an airlock in the radiator and the radiator requires bleeding.
- The water in the system is not circulating and the radiators require balancing
How to Bleed a Radiator
‘Bleeding’ a radiator means releasing trapped air in the radiator. This is done by pressing in a small valve at the top of the radiator, located at one end, with a ‘radiator key’ and holding in until all of the air has been released. NB your radiators may have a decorative grill and side panels which will cover the valve. You will need to lift the grill and side panels off first.
How to Balance a Radiator
When water does not flow around the whole system then the radiators will need balancing. Water will always take the easiest route and often this means it will skip out radiators and travel back to source without heating them.
To encourage water to flow fully around the system, it necessary to restrict the path through the easiest course. This is done by tightening the ‘lock shields’ (valves) and restricting the flow to the ‘easy to reach’ radiators. Balancing radiators is a specialist skill that will usually require the help of an experienced plumber or heating engineer.