Why Is My Boiler Making a Loud Vibrating Noise?

There’s nothing like a cozy room and warm water in the cold season. Your boiler makes it happen for you. The people living in colder parts of the world may be more familiar with the importance of a boiler than anyone else. So, a boiler should be and is one of the best winter companions if you live in a cold area, as long as it works efficiently. But that depends a lot on the upkeep of your boiler. 

Based on the level of maintenance, normally, a boiler can give you a trouble-free service during the peak winters. But at times, it may develop faults. Like any other machine that deals with water, especially hard water, the boilers are also prone to give you a tough time. The fuel source also plays its role, especially gas or coal.

Additionally, the boiler comprises of various moving parts, which may add to the worries, you may have to face. So, it’s not an extraordinary situation, if your boiler or any of its allied components starts malfunctioning, the most common being the abnormal sounds or noises. However, you need to determine the actual reasons for such abnormal sound or noise and get it fixed before it becomes a major fault. But before we jump on to the possible faults, let’s have a brief look at the types and workings of a boiler.

Classification of Boilers Based on Energy Source

Boilers come in different varieties when it comes to the source of energy they use for producing hot water:

1. Gas Boilers – Gas-operated boilers are the most commonly used boilers these days. They are quite efficient but need a bit more care and maintenance. They are equally useful for homes and commercial buildings. These are often used as part of an integrated heating system in large buildings. Gas boilers are best for buildings with central heating systems. 
2. Electric Boilers – These are also quite popular, especially in the areas where gas is not available. An electric boiler needs lesser maintenance as compared to all other types. But these are less efficient as compared to gas boilers, in the sense that they take more time to heat the water. These are, however, considered as the best environment-friendly boilers.
3. Oil Boilers – Normally, this type of boilers use kerosene oil. These are more popular in areas with no gas supply. But the hassle of regularly feeding oil makes them quite cumbersome. Additionally, they are quite harmful to the environment due to the emission of carbon.
4. Coal Boilers – This type of boiler uses coal or firewood as an energy source. These are not commonly used in homes. Their utility is more relevant to industrial projects, where they need to produce steam. Despite their utility in industries, these can prove quite dangerous at times. Due to high pressure, coal boilers have the tendency to explode if not properly taken care of. Moreover, you need to spare quite a large space for their installation and work.

Classification of Boilers on the Basis of Heat Exchange System

Boilers are meant to produce hot water, which happens through a heat exchanger. There are two different ways of doing so, mostly used in boilers:

• Water Tube Boilers – Here the heat is produced in the heat chamber and water passes through it via water tubes. The heat chamber remains filled with hot flue gases. When water passes through these tubes, which are installed in the heat chamber, it gets heated.  
• Fire Tube Boilers – In this type of boiler, the process is entirely reversed as that of the water tube type. Here the flue gases are in the tubes that are installed in a shell. Water passes through this shell. Water gets heated when it comes in contact with the fire tubes, which contain hot flue gases.

The water tube boilers are considered more efficient than the fire tube boilers. Reason? They are more compact in their build and can produce hot water more efficiently.

Classification of Boilers Based on Utility

The following three types of boilers are most commonly used in homes and industries:

• Combination or Combi Boilers

Combination boilers are commonly known as Combi Boilers. These are mostly the first choice of homes. As they are capable of providing heat and hot water simultaneously, why do they get the name combination or combi boiler? There’s no separate tank linked with them; these are wall-mounted.

A combi boiler can also be referred to as an Instant Boiler, as they start heating the water immediately when you open a tap.  The ignition is automatically triggered when you start using the water. The heat exchanger gets heated instantly and starts heating the water. That’s why you need to connect it with the energy/fuel source all the time for its continuous performance.

But it has its limitations. It cannot supply hot water to multiple users at a time. So, it is useful for small households only, with a single washroom and less than ten radiators. Moreover, it cannot generate pressure. The flow of water is entirely dependent on the inflowing water pressure.

• Heat-only Boilers

This type of boiler is commonly known as a conventional boiler. Regular boiler or Heat-only boiler are the other names associated with this type of boiler. They need a separate water tank for the supply of hot water.

When the boiler is ignited, the heat exchanger starts heating the water pumped into the storage tank. This heated water is then transported to the radiators to heat the premises. Hot water is also transported to the wash rooms, so you get warm water when you switch on the taps.

They are relatively less efficient as compared to the combi boilers. They cannot provide hot water instantly; rather, you will have to wait for the hot water coming your way. It is more costly and needs more space for installation. But it is useful for larger households, having multiple washrooms and more than 10 radiators.

• System Boilers

These are more like a conventional or heat-only boiler. But they don’t have a storage tank. Secondly, various components such as pumps and valves are built-in, unlike conventional boilers, where these parts are separately installed.  System boilers are a part of the integrated heating system.

Their work is almost the same as that of heat-only boilers. The only difference between them is in some of their components. In fact, system boilers can be referred to as the modern and upgraded version of regular boilers.

However, one of the weaknesses of this type of boiler is the low pressure. Like the combi boilers, they are also dependent on the pressure of incoming water, as they cannot generate outgoing pressure. Water will be supplied at the same pressure as it is coming into the boiler.

Abnormal Sounds, Vibration and Noise in Boilers

A boiler is not a quiet and soundless kind of machine. It has to heat the water, which is a sound-generating process. Moreover, it has water pumps, which also cause a particular sound. So, a boiler does produce various sounds, which should not be a cause of worry for you. But the problem starts when you notice some extraordinary or abnormally loud sounds from the boiler. It may also suddenly start vibrating.

Loud noise and vibration are often due to the air trapped somewhere in the boiler. It is also an indication of radiator heads being off. Most commonly, you will notice sounds such as kettling or whistling, humming, rumbling, gurgling, buzzing and tapping. Additionally, you may also come across extraordinary vibration of the boiler.  

Let’s explore what are the possible abnormal sounds, what are the reasons and how you can fix them:

• Dripping Sound – Boiler May Be Leaking

A dripping sound is a clear indication that there is a water leakage in your boiler. Obviously, you can see the dripping water if it’s an external leakage, but it remains hidden when the leak is internal. Leakage normally occurs when any of the pipe or tank gets eroded. It can also happen due to some broken component, such as a heat exchanger. Or it may be due to broken seals.

If you face such a situation, you will have to call a gas-safe engineer urgently. Don’t try any DIY method. The only thing you can do is to switch off the boiler and cut off the supply of water by closing the inlet valves and waiting for the engineer to come.

• Gurgling Sound – Trapped Air in the Boiler

If you notice a gurgling or banging sound in your boiler, it may be due to air trapped somewhere in your boiler. It generally happens with the boilers linked with the central heating system, when water is heated and instantly gets cool due to excessive use. This results in air trapping. This can be fixed by releasing the trapped air from the pumps. You may also need to bleed the radiators in some cases. Normally, you should be able to fix this problem yourself, but if the problem persists, you may have to contact a boiler engineer.

• Whooshing Sound – Vibrating Boiler

A whooshing sound and noticeable vibration of the boiler are something you must not ignore. It may happen due to a variety of reasons, most common being the blocked flues. You may fix it easily by checking and removing any blockage from the flues. Once done, you can recheck whether the air flow has gotten smoother and there isn’t any noise or vibration.

• Screeching Sound – Creaking Pipes in the Boiler

A screeching sound may be due to the creaking pipes in your boiler. If that’s the reason, you may also notice a tapping, clicking or banging sound coming out of the boiler. It often happens if the pipes are not properly fixed or hooked.

In this case, you may try to hook the pipes using clips.

• Whistling Sound – Lime-Scale Buildup in the Boiler

A very common problem with boilers is the chance of buildup of lime-scale in the water tank, pipes or heat exchanger. This typically occurs when the water supplied through the mains is hard. It can cause choking or blockage. But the actual issue with the scale deposit is that it gets heated very quickly. This results in overheating, which in turn causes whistling noise. Overheating can also result in cracking or breaking of seals if not fixed in the early stages.  

If you notice this situation, you should immediately call a gas-safe engineer. If the problem has been there for a prolonged time without being noticed by you, there is every likelihood of your boiler been damaged severely. However, if the problem was detected at an early stage, the engineer should be able to descale the affected components by cleaning it with a lime-scale remover. He should also install a lime-scale inhibitor to reduce the possibility of future accumulation of lime in your boiler.

However, it is highly recommended for the areas having a hard water supply to install the lime-scale inhibitor, invariably.

• Kettling Sound – Radiator Heads Issue

The kettling sound is an indication that the boiler is producing overheated water. You need to immediately check the radiators. This may be due to the radiator head being off.

• Clicking and Tapping Sounds – Ignition Issue

A clicking sound may typically be due to a fault in the ignition system. A tapping light is yet another indication of a faulty ignition unit. If this happens, you need to call the gas-safe engineer. Don’t try to fix it yourself.

• Humming sound – Loose Components in the Boiler

The humming sound is mostly normal when the boiler is on. But sometimes you may feel some abnormality in this sound. It may be due to some loose inner parts of the boiler. It may also be a result of the high pressure of water or the pumps might be running faster than normal.

You can tighten any loose screws or bolts that may be causing this abnormal sound. But for that, you have to switch off the boiler. But if the problem is inside the boiler, don’t try to play with it; just call the engineer. If the problem is with a fast-running pump, reduce its speed to a lower level. In case of a high water pressure, you may need to call the engineer who can set it right.

Conclusion

Boilers do make some level of noise during their normal operation. Nothing to worry about. But if the sound or noise is more than normal, that’s the time for you to start worrying. If it starts vibrating and becomes too noisy, it’s an indication that you need to react swiftly.

Some abnormal sounds can be removed by following a few simple steps but most of the time, you can’t do it yourself. It is always advisable not to try too much with your boiler. Just call the gas safe engineer to find out the actual problem and fix it. You can, however, reduce the chances of such an abnormality by regular maintenance and servicing of the boiler, especially right before the onset of winter.