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Why Are Radiators Cold At The Bottom?

Advice Centre
Welcome to our Advice Centre, where you’ll find inspiration, practical tips and now-how guides for the best and most economical ways to heat your home.
Why Are Radiators Cold At The Bottom?

The moment has arrived! It’s time to switch your heating on after a long hot Indian summer. However, you’ve recently discovered that your radiator has cold patches at the bottom of it, causing distress and panic!

Don’t fear, our experts at UK Radiators will be able to help you identify the possible causes and how you can fix your cold radiator.

The number one cause of radiators becoming cold at the bottom is internal corrosion – where the metals in the heating system react to oxygen and become compromised. This leads to a build up of what is often called ‘sludge’. The sludge sits at the bottom of the radiator and prevents it from getting hot.

A infographic explaining why radiators are cold

What Causes Internal Corrosion/Sludge

In short, the cause is an improperly maintained system. To function correctly and efficiently, our central heating systems rely on water PH levels, chemical management (appropriate use of inhibitors), and regular boiler and system health check-ups by a professional.

Ways To Prevent Sludge

As with most things, prevention is better than cure. Thankfully, there are many effective ways to prevent a build-up of sludge in your heating system and get your radiators running efficiently.

In our rust and corrosion blog, we have outlined some system changes and steps to follow annually to prevent internal corrosion

These include:

  • Frequent servicing and how these can save you in the long run.
  • Appropriate PH balance for the metals present in the system.
  • Central heating inhibitors and when to use them. 
  • How to check the water in your radiators. 
  • How to check your radiators are heating up correctly. 

If you are already the victim of internal corrosion, then you can read more about how to remove internal corrosion from your radiator here.

Avoid Increasing The Temperature

Often, a common mistake people make when fixing cold patches in their radiator is by turning their thermostat up.

We advise against increasing the temperature as this makes your boiler work overtime, making it run less efficiently. Due to the heavy formation of sludge, the increased temperature will still prevent your radiator from heating effectively.

Common Radiator Issues

With radiators being cold at the bottom, it is also common to encounter radiators being cold at the top too. Fortunately, this problem is also fairly easy to resolve by bleeding your radiators to get your radiator effectively distributing heat.

Still having issues with your radiator? It might be time to say farewell. Browse our eclectic range of stunning radiators to find the perfect replacement for your home.