A radiator that is warm at the top but stubbornly cold along the bottom is one of the most common heating complaints we see in homes around Wigston and South Leicester. The good news is that it rarely means a new radiator. It almost always points to sludge settling inside, and there are a few things worth checking before you pick up the phone.
If the top of your radiator gets hot quickly but the bottom third stays cold to the touch, the likely culprit is iron oxide sludge. Over the years, the steel inside your radiators and pipework corrodes slightly, and that fine black grit sinks to the lowest point of each radiator, blocking the flow.
This is different from a radiator that is cold at the top, which usually just needs bleeding to release trapped air. Cold at the bottom is a flow problem, not an air problem, so bleeding the radiator on its own will not fix it.
Many properties around Wigston, Oadby and South Wigston have heating systems that are fifteen years old or more, often without an inhibitor topped up or a magnetic filter fitted. Leicestershire's mains water is moderately hard, which does not cause the sludge directly but does encourage scale in the boiler and hotter spots where corrosion speeds up.
If you have several radiators going cold at the bottom, or the kitchen and hallway ones that sit lowest in the system are worst, that is a strong sign the whole system needs attention rather than a single radiator.
Before booking anyone, it is worth ruling out the simple things. Make sure both valves at the bottom of the radiator are fully open, including the lockshield valve under the plastic cap, which sometimes gets nudged closed. Turn the heating up and feel each radiator after about twenty minutes.
If only one radiator is affected and the rest of the house is fine, balancing the system or a single power flush on that radiator may sort it. If several are cold along the bottom, you are looking at a system clean.
Clearing sludge properly means a power flush or a chemical flush, where the system is circulated under pressure to lift and remove the debris, followed by fresh inhibitor and ideally a magnetic filter fitted on the return pipe. As a rough guide, a power flush on a typical three or four bedroom home tends to run from around 350 to 600 pounds depending on the number of radiators and how blocked the system is.
Occasionally a radiator is so packed with sludge that it is quicker and cheaper to remove it, flush it through outside, and refit it. We will always tell you honestly which approach makes sense for your system rather than defaulting to the most expensive option.
You can try bleeding it and checking the valves are open, but if it is cold at the bottom due to sludge, a proper power flush or removing and flushing the radiator is needed. That part is best left to a plumber with the right equipment.
Usually not. Bleeding releases trapped air, which causes a cold top, not a cold bottom. A cold bottom is a flow problem caused by sludge sitting at the base of the radiator.
Have an inhibitor added after any flush and ask for a magnetic filter to be fitted on the return pipe. Topping up the inhibitor every few years and getting the boiler serviced annually keeps the system clean.