Why Is My Radiator Cold at the Bottom?

Why Is My Radiator Cold at the Bottom?

Noticing your radiator is warm at the top but cold at the bottom? This is a common heating issue in homes across Kent — especially in older properties in areas like Sittingbourne, Canterbury, and Medway. In this guide, we’ll explain what causes uneven radiator heating, how to fix it, and when to call in the pros.

Common Causes of Poor Radiator Circulation

When a radiator heats unevenly — typically cold at the base — it’s usually caused by a build-up of sludge, rust, or limescale inside the system. Over time, debris settles at the bottom and blocks the flow of hot water. This is especially common in hard water regions like Kent, where scale can build up faster than usual.

Symptoms of a Blocked Heating System

• Radiators slow to heat up
• Some radiators heat better than others
• Noisy boiler or pipes
• Cold patches across multiple radiators
• Frequent need to bleed your radiators

Can You Fix It Yourself?

You can try bleeding the radiator first — this removes trapped air and improves water flow. However, if the base stays cold, air isn’t the issue. It’s more likely sludge or blockages, and bleeding won’t resolve it. That’s when professional help is needed.

What Power Flushing Can Do

Power flushing involves pumping water and specialist cleaning chemicals through your heating system at high pressure. This dislodges sludge, scale, and other debris to restore full circulation. A clean system makes your boiler more efficient and helps all your radiators heat evenly.

When to Call a Heating Engineer

If your radiator has cold spots at the bottom and you’ve already tried bleeding it, don’t ignore the problem. Sludge build-up can put extra strain on your boiler and reduce its lifespan. At Plumble, we help homes across Kent — from Faversham to Folkestone and beyond — get their heating back to full health with expert system cleaning and power flushing.

→ Book your system clean or power flush with Plumble