Heating Off But Radiators Hot? Here’s Why

Radiators are a lifesaver on cold, rainy days. With them, you’re toasty and cuddled up with a cup of tea – but on a hot day…. it’s a different story. Especially when you explicitly turned off the heat, only to have the radiators still, well, radiating. Luckily for you, you’re in the right place. DreamyHome has a guide ready and waiting to help you get this fixed, and your radiators cooled off. Keep reading to learn why your heating is off but radiators are still hot.

The most common causes for the heating being off but radiators hot are an issue with your diverter or check valves.

Unfortunately, these aren’t fixes for the layman to attempt. Once you’re sure the issue lies in one of these two places, you’ll want to call a Gas Safe certified engineer to fix the issue. Don’t worry – they don’t bite (much).

Troubleshooting: Heating Off But Radiators Hot

As we said above, it’s likely that your issue lies in one of two valves. Let’s take a look – no sense in wasting time while you sweat away.

Diverter Valve Issues

These are the valves that open and close to cut off hot water to your radiators and heating system. It will close to allow hot water to go to your taps, rather than radiator (or vice versa).

Because these valves open and shut constantly, it’s entirely possible for them to fail or get stuck. You may notice that hot water continues to flow to your radiator, or that the tap is warmer than usual. It’ll be especially noticeable if your heating is entirely switched off but you’re still warming up.

You can try to locate the valve (usually near the boiler) and check to see if it’s switched to manual or auto. Sometimes it’ll get stuck in a weird “in-between” spot and simply pushing it all the way to the automatic side may resolve the problem. Otherwise, you’ll need to call for help.

Check Valve Issues

This is more common in older boilers because they keep water hot at all times. It then goes through your radiators using convection, A check valve is what stops the heated water from going to your radiators when the heat is off. If your valve is broken, blocked, or stuck, the heat will naturally rise through your home, heating the radiators.

I really wish there was more I could say other than “call for help,” but this is really all you can do. It’s difficult (more often than not) to access check valves, and having a professional confirm this is the issue will save you so much time. Please – call a Gas Safe engineer to locate and fix the problem.

Final Thoughts

This is one of those articles that I feel bad writing. DreamyHome loves being the answer to all of your issues, but unfortunately, sometimes the answer is “call a professional.” These valves are often damaged over time or blocked by debris and mineral buildup, causing them to stop working.

While it’s never ideal to have to call for help, it’s times like this that you should be thankful you don’t have to do it yourself. Trust me – the professionals will do a much better job than you ever could.

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About the Author Harry Thompson

Involved in home renovations throughout his life, Harry is an expert in everything to do with home and garden DIY. In his spare time, he enjoys cooking and tending to his garden.