Why Does My Radiator Make Noise at Night?

Short answer

Radiators often make noise at night because heating cycles change, pipes cool and contract, water flow slows, and background noise drops. In most cases this is normal, but some sounds can indicate trapped air, pressure issues, or valve problems that are worth checking.

Why radiators are noisier at night

Radiators tend to make more noticeable noise at night for a few simple reasons:

• Heating cycles change
  Central heating often switches on and off more abruptly overnight, especially with timers or smart thermostats.
• Metal contracts as it cools
  As pipes and radiators cool down, the metal shrinks slightly. This can cause clicking or ticking sounds.
• Water flow slows
  Reduced demand in the system can exaggerate bubbling or movement noises.
• Your home is quieter
  Sounds that happen during the day become far more noticeable once everything else is quiet.

These factors together explain why a radiator can seem fine during the day but noisy at night.

Match the noise to the cause

The type of noise matters more than the fact it happens at night.

Clicking or ticking

• Caused by metal expanding or contracting
• Very common in older systems
• Usually harmless

Gurgling or bubbling

• Caused by trapped air in the radiator
• Often more noticeable when the system cools
• Usually fixable by bleeding

Banging or knocking

• Water flow hitting closed or partially closed valves
• Sometimes linked to thermostatic radiator valves (TRVs)
• Not normal if loud or frequent

Hissing

• Pressure imbalance or valve issue
• Should be checked if persistent

Is it safe to ignore radiator noise at night?

In many cases, yes — but not always.

Usually safe to ignore if:

• The noise is light clicking or ticking
• It only happens briefly when heating turns on or off
• The radiator heats evenly

Do not ignore it if:

• The noise is loud banging or knocking
• It wakes you regularly
• The radiator stays cold at the bottom
• Boiler pressure keeps dropping

What to check first (in order)

Before calling anyone out, check these in order:

1. Listen carefully
   Identify whether the sound is clicking, gurgling, banging, or hissing.
2. Check boiler pressure
   Low or unstable pressure can cause unusual noises.
3. Bleed the radiator
   If you hear gurgling or bubbling, trapped air is likely.
4. Check the valve
   Especially thermostatic radiator valves in bedrooms, which can close aggressively at night.
5. Do nothing
   Mild clicking during temperature changes is normal.

Why this often happens in UK homes

Radiator noise is particularly common in UK properties because:

• Many homes have older heating systems
• Narrow pipework exaggerates expansion sounds
• Thermostatic valves are widely used
• Night-time temperature drops are common

These factors make occasional radiator noise normal rather than a sign of failure.

When to get help

You should consider calling a heating engineer if:

• Banging continues after bleeding
• Multiple radiators are affected
• Boiler pressure drops repeatedly

Otherwise, occasional noise at night is usually not a fault.

Final reassurance

If your radiator only makes mild noise at night and still heats properly, it is usually normal. Most heating systems make small sounds as temperatures change — they are simply easier to hear when the house is quiet.

Internal links to add (important)

• Radiator Clicking or Ticking: Is It Normal?
• Radiator Banging or Knocking: Should You Worry?
• Radiator Gurgling Sounds: Causes and Fixes