The radiators in your home are connected by pipes that are controlled by valves. Partially closed radiator valves in a steam system may be trapping condensation in your radiators instead of allowing it to flow back to the boiler (i.e., return), which can cause a banging noise when new hot water enters the radiator.
How to Fix a Banging Noise in Your Radiator. In some cases, this can be solved by draining your radiator to free up trapped water and air. You need to ensure you turn off the boiler and gas supply, turn off the intake valve and wait for the radiator to cool down and open the drain valve again.
Check with maintenance, but you may be able to shut the valve before going to bed. That should shut off the heat to your bedroom and hopefully prevent the loud banging sounds. The other option for them would be to bleed the system, so that they can get rid of any excess air etc in the pipes.
Dirty Blower Wheel
Regular maintenance always benefits your furnace, and this definitely applies in the case of the blower wheel in your furnace. If the blower wheel becomes unbalanced, you may hear knocking sounds when the furnace runs.
The banging or water hammer would typically be from some water collecting in a horizontal run toward the radiator that has a sag or is not pitched back to the boiler. If the radiator pitch is OK you can also try raising the radiator an inch or half inch or so (maintaining pitch).
Bleeding your radiators will release any air that may be trapped inside. When air gets into your heating system, it can cause a banging noise because it increases the pressure in the system. Releasing pressure by bleeding the pipes of excess air can stop the banging noise from occurring.
Radiator valve hammer is caused by a high velocity of water dragging down the spring loaded plunger of a TRV (thermostatic radiator valve). The return spring in the plunger will always try to lift the mechanism and if the water flow is strong enough, it will try to drag the plunger down.
Furnace Screeching or Scraping
The blower fan may have come loose, letting the blades drag across the furnace casing. A scraping noise can also indicate other parts of the system have loosened. If you are unsure of the cause of the noise, turn the furnace off and have a technician come and take a look at it.
🧰 How to Fix It: In this case, you'll have to “bleed” your radiators. This is done by opening up the bleed valves on each radiator and letting out a small amount of air until the noise stops. You'll likely have to do this multiple times, but try not to let too much water out, or you risk damaging your system.
Popping or Banging
When your heater turns on, noises like popping and banging are normal. There could be a few reasons why heaters make this sound, like dirty burners that need cleaning, or an excessive amount of gas inside the chambers.
Trapped air
Water and air flowing through pipes and radiators can result in clicking, ticking or tapping noises. While the sound is a little irritating, more importantly, this trapped air could mean your radiators aren't heating up properly.
Pops and bangs are usually from the ducts expanding and contracting. Dirty air filters, vents, and ducts can make a lot of noise. Professional duct inspection reveals noisy HVAC inefficiencies.
If it's just creaking or clicking when your heating goes on or off, it's just the metal of the radiator expanding and contracting.
You should bleed your radiators at least once a year, typically before winter arrives in order to ensure the efficiency of your heating system. Regularly checking for trapped air also helps to make sure that your system operates effectively and reduces energy consumption.
To do this, shut off your home's main water valve, then open the highest faucet in your home. Next, turn on the lowest faucet in your home and keep it on until all water has drained. Finally, reopen the main water valve to refill your pipes.
In most cases, noisy pipes are caused by movement as they expand and then knock against other surfaces. Therefore, one of the best ways to solve this problem is to check that all pipes are securely fastened and that they're not touching anything else.
It's easy to avoid this problem by regularly changing your furnace filter. Our HVAC technicians suggest replacing the filter once every three months or as soon as it's no longer a clean white color. If you have pets in the house, you need to change it every month.
Air pressure buildup within your HVAC system can push against the walls of the ducts, causing them to expand, which causes a banging or popping sound several seconds after you turn the system on.
Oil-filled electric radiators can make a slightly different sound when they heat up, sometimes described as a crackling, popping or a clicking noise – this is completely normal and caused by the expansion of the thermal fluid.
Banging Sounds Coming From the HVAC Ductwork
This type of noise usually occurs in quick, short bursts. It is the result of expansion and contraction in the duct walls as internal temperatures rise or fall. This type of noise can also be the result of pressure changes within the ducting.
Believe it or not, a cracking sound from your heater is normal and nothing to worry about. After a heating cycle, heated metal in your ductwork and your furnace can make a crackling noise as it cools down and turns off.
Why is my radiator making a banging noise? Banging noises in radiators often indicate a problem known as "water hammer." Water hammering tends to be caused by water flowing one way in your system then having to flow in the opposite direction when a tap is turned on.
SOLUTION: The first thing to do is to bleed the air from the radiator, which will require the key that accompanies the heating system. Not to worry if the key is lost, check out our tips on how to bleed a radiator, and how to bleed a radiator without a key.
Install a water hammer arrestor: This device has an air-filled cylinder to absorb the impact of abrupt increases in water pressure. Most water hammer arrestors are installed between the shut-off valve and supply line via screw-type connectors.