If you’ve noticed your radiator is cold at the bottom but warm at the top, you’re not alone. A radiator hot at the top and cold at the bottom is a common issue in UK homes and is usually caused by a build-up of sludge or poor water circulation in your central heating system.
The good news is that, in most cases, it can be fixed and with the right maintenance, you can prevent it from happening again.
How radiators should heat up
A healthy radiator should feel warm all over from the top to the bottom when your heating is on. Hot water flows from your boiler into the radiator, circulating evenly before returning to the system.
If the bottom of the radiator is cold but the top feels hot, something is preventing heat from reaching the lower section. Understanding why this happens will help you find the right solution.
Common causes of a radiator cold at the bottom
What if the top of the radiator Is cold?
A radiator cold at top or top of radiator cold usually points to trapped air rather than sludge. Air rises to the top of the radiator and prevents hot water from filling it completely.
Solution: Bleeding your radiator will release the trapped air. This is a quick and simple job that most can do themselves with a radiator key just remember to switch your heating off before you start.
Find out moreWhy you shouldn’t ignore the problem?
A radiator hot at top cold at bottom might seem like a minor issue, but leaving it can:
- Reduce the efficiency of your heating system
- Increase your energy bills
- Put unnecessary strain on your boiler
- Leave some rooms feeling cooler than others
Fixing the problem promptly will keep your home comfortable and help your boiler run efficiently.
Find a local installer
What to do if you notice this problem?
While it’s helpful to know the common causes of a radiator hot at top cold at bottom, only a trained heating engineer can confirm the exact reason in your home. They have the tools, knowledge, and expertise to safely inspect your system and restore it to full performance.
If you see signs of uneven heating whether it’s radiators cold at top or the bottom of radiator cold it’s best to arrange a professional assessment.