Radiator Still Noisy After Bleeding: What It Means

Short answer

If your radiator is still noisy after bleeding, it usually means the noise is not caused by trapped air alone. Common causes include valve behaviour, pipe movement, pressure imbalance, or system-wide circulation issues. While this is often not serious, it is worth checking a few things before ignoring it.

Why bleeding does not always stop radiator noise

Bleeding a radiator removes trapped air, which fixes many gurgling and bubbling noises. However, not all radiator noises are caused by air.

If the noise continues after bleeding, it may be due to:

• metal pipes expanding or contracting
• thermostatic radiator valves opening or closing abruptly
• pressure changes in the system
• pipework moving against floors or walls

Bleeding solves air problems, but it does not address these other causes.

What type of noise you hear matters

Identifying the remaining noise helps explain what is happening.

Clicking or ticking after bleeding

• Metal expansion or contraction
• Very common
• Usually harmless

Banging or knocking after bleeding

• Water flow hitting valves or pipe bends
• Often pressure or valve-related

Hissing after bleeding

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

Gurgling that returns quickly

• Air entering the system again
• Possible pressure problem

Is it normal for a radiator to still make noise after bleeding?

In many cases, yes.

Usually normal if:

• the noise has changed or reduced
• the radiator heats evenly
• the sound is light clicking or ticking

Not normal if:

• loud banging continues
• gurgling returns within days
• boiler pressure drops repeatedly
• several radiators remain noisy

Bleeding should improve air-related noise, but it will not silence all sounds.

What to check next (in order)

If bleeding did not fully solve the problem, check these next:

1. Check boiler pressure
   Low pressure can allow air to re-enter the system.
2. Check the radiator valve
   Thermostatic valves can cause knocking or clicking.
3. Listen for pipe movement
   Pipes moving through floors or walls can still click.
4. Check other radiators
   Multiple noisy radiators suggest a system-wide issue.
5. Observe over a few heating cycles
   Normal expansion noises often settle.

Why this is common in UK homes

Radiators often remain noisy after bleeding in UK properties because:

• heating systems cool fully overnight
• pipework runs through timber floors
• thermostatic valves are widely used
• older systems react strongly to pressure changes

These factors make some noise normal even after air is removed.

When to get help

You should consider professional advice if:

• banging or knocking continues
• air keeps returning quickly
• boiler pressure is unstable
• heating performance drops

An engineer can usually identify whether balancing or valve adjustment is needed.

Final reassurance

If your radiator is still noisy after bleeding, it does not usually mean something is wrong. Bleeding removes air, but other normal system behaviours can still cause sound. As long as the radiator heats properly and the noise is mild, it is rarely a serious issue.

Internal links to add

• Radiator Gurgling Sounds: Causes and Fixes
• Should I Worry About a Noisy Radiator?
• Radiator Clicking or Ticking: Is It Normal?