Bleeding the heating system, simple solution
Is your towel radiator or bathroom heater only getting halfway warm? Then there's a good chance there's air in it. Bleeding the radiator is the solution. Fortunately, it's easy to fix. A simple bleed will remove the air from the radiator and get the hot water flowing properly again. In this blog post, we'll explain step by step how to do this yourself – without having to call a plumber.
Why bleeding your heating system is important
Air bubbles in your radiator block the flow of hot water. This causes (part of) the radiator to remain cold, while your boiler is working hard. This wastes energy and reduces comfort – especially in the bathroom, where you want a warm towel or a cozy space.
An advantage of electric towel heating is that bleeding is no longer necessary
How air is created in a radiator
Air in a radiator usually occurs due to natural processes in your central heating system. Here are the main causes:
- Topping up the central heating system
When you refill the boiler with water, a little air always comes along, no matter how careful you are. This air eventually accumulates in the radiators.
- Microbubbles in the central heating water
Water always contains a small amount of dissolved air. As it circulates through the pipes, tiny air bubbles form, clump together, and accumulate at the top of radiators.
- Work or leaks
If work has been done on the system (for example, replacing a radiator or having the boiler serviced), additional air can enter the system. Small leaks in fittings can also draw in air.
- Temperature fluctuations
When the water in the system cools or heats up, this can cause pressure changes that create or release air from the water.
How do you recognize air in a radiator?
- Top of the radiator remains cold
- Gurgling or bubbling sounds
- Uneven heating
Reduced central heating pressure
What do you need?
To bleed your bathroom heating you will need the following:
- A vent key (available at hardware stores)
- A cloth or old towel
- A small container or bowl to collect any water
- Possibly a screwdriver (for some modern radiators)
Bleed your bathroom heating in 6 steps
-
Turn off the heating
Let the system cool down. It's important that the heater is cold to work safely. -
Find the bleed valve
This is usually located at the top of the radiator, on the side. Place a cloth underneath and have your container ready. -
Open the valve
Use the key to slowly open the valve. You'll hear a hissing sound: that's the air escaping. -
Wait until water comes out
As soon as a trickle of water comes out, all the air is gone. Then close the valve tightly again. -
Check the CV pressure
After bleeding, the pressure in your central heating system may drop slightly. Check if it's between 1.5 and 2 bar. If not, top up the water through the boiler. -
Turn the heating back on
Now that the air is out, the radiator can heat optimally again. You'll feel the difference within a few minutes.
Extra tip
Do you have multiple radiators in your home that aren't heating up properly? Always start bleeding from the bottom and work your way up. Air rises in the system.
This simple step keeps your bathroom nice and warm and saves energy. Ideal for preparing for the colder months, for example, every fall.
