Why Bleeding a Radiator Is Important

If your radiator feels cold at the top but warm at the bottom, it may have trapped air inside. This air stops hot water from flowing properly, which means:

• You get less heat in the room
• Your boiler works harder
• You waste energy and money

The solution is simple: bleed the radiator. It’s easy, safe, and only takes a few minutes!

What You Need

Before you start, make sure you have:

• A radiator key (you can buy one at any DIY store)
• A cloth or small towel (to catch water)
• A container or bowl (optional, for drips)
• Gloves (optional, for comfort and safety)

Step-by-Step: How to Bleed a Radiator

1. Turn Off the Heating
   Let your radiator cool down. This prevents hot water from spraying out and makes the process safer.
2. Find the Bleed Valve
   Look for a small square or slot screw at the top corner of the radiator. That’s the bleed valve.
3. Insert the Key and Turn Slowly
   Place the radiator key onto the valve and turn it anti-clockwise just a little—about a quarter turn.
   You’ll hear a hissing sound. That’s the air escaping.
4. Wait for Water
   Once water starts to come out (a steady stream, not splashing), the air is gone. Quickly turn the key clockwise to close the valve.
   Wipe away any water with a cloth.
5. Check Your Boiler Pressure
   After bleeding, go to your boiler and look at the pressure gauge. It should be around 1.0–1.5 bar. If it’s too low, top it up by following your boiler’s instructions.

How Often Should You Bleed Radiators?

We recommend bleeding your radiators:

• Once or twice a year, especially before winter
• Whenever you notice cold spots or strange noises
• After any plumbing work or system refill

Helpful Tips

• Bleed downstairs radiators first, then move upstairs.
• Don’t over-tighten the valve—just close it snugly.
• If you’re unsure or uncomfortable, it’s always OK to call a professional.

Why It Matters

Bleeding your radiator is a simple but powerful way to:

• Improve heating performance
• Save energy and money
• Keep your home warm and comfortable

At Rocotherm, we design radiators to be efficient and reliable—but a little maintenance goes a long way. With clean water flow and no trapped air, your radiator can do its job beautifully.

Final Word

Bleeding a radiator doesn’t require tools, time, or a technician—just a bit of know-how.
Now that you have it, your heating system will thank you.

Stay warm.
Stay efficient.
Stay in control—with ROCOTHERM.