Winter Woes Why Is My Radiator Not Heating Up?

There’s nothing worse than waking up in mid-December to a freezing house because your radiators aren’t doing their job. You’re not alone though. Radiator problems are one of the most common issues households face when the temperature drops.

In this article, we’ll run through 5 common reasons radiators fail in winter and easy ways to heat them up again.

5 common reasons radiators won’t heat up in winter

The first step to solving your radiator woes is to pinpoint the exact cause. While the following list isn’t exhaustive, you can usually trace the problem back to one of these common issues.

1. Air trapped in the system
2. Sludge or debris build-up
3. Radiator valves stuck or closed
4. Boiler pressure problems
5. Thermostat or timer settings

Trapped air in the system

When air gets trapped in the heating system, it creates “airlocks”. These are small air bubbles that block the flow of hot water to the radiators. While they can collect anywhere in the system, there are a few hotspots to be aware of:

• At the top of radiators
• Elevated pipework
• Towel rails
• Expansion tanks and cylinders in lofts

What you can do to help: Bleed the radiator with a radiator key until water starts to flow steadily.

Sludge or debris build-up

Over time, tiny bits of rust, dirt and limescale mix together to create a thick sludge in your pipework. This build-up blocks hot water from circulating properly, often leaving radiators cold or patchy.

It’s also worth mentioning that this forces your heating system to work harder, driving up energy bills and putting strain on the boiler's heat exchanger and pump.

What you can do to help: Book a power flush with a heating professional.

Radiator valves stuck or closed

In a nutshell, radiator valves regulate the flow of hot water in and out of the unit. They often get stuck after months of inactivity over the summer, which is bad news once the winter weather rolls in.

What you can do to help: Check that both valves are open and give the thermostatic valve a gentle twist to loosen. If this doesn’t work, it may need replacing. It’s also a good idea to turn your heating on occasionally throughout summer.

Boiler pressure problems

Boilers need to generate enough pressure to circulate hot water around the system. If the pressure level is too low (usually below 1 bar), radiators may heat unevenly or not at all.

What you can do to help: Re-pressurise the boiler via the filling loop. If this doesn’t solve the problem, it indicates a leak or a faulty component. Call a professional for further investigation.

Thermostat or timer settings

Sometimes the problem isn’t the radiator at all, but the thermostat. If it’s set too low, the boiler may not switch on, leaving radiators cold even though the system itself is working fine.

What you can do to help: Double-check your thermostat settings. The thermostat must be set above room temperature for the heating to activate.

We can help you winter-proof your home

If you’ve tried these quick fixes and your radiators are still not working, it’s time to enlist the heating specialists. At Home Heating Experts, our qualified heating engineers can diagnose the problem, carry out any repairs and make sure your home stays warm all winter.

Don’t hesitate to contact us today on 07990755180 or get a quick quote online.