Heating Unit Making a Noise? – Common Reasons Your Boiler or Furnace is Making Sounds

old HVAC system out in the snow

Heating Unit Making a Noise? - Common Reasons Your Boiler or Furnace is Making Sounds

Various issues within your heating system could be identified by the sound the boiler or furnace is making. These sounds are distinct and can be used as tools that indicate different damaged parts or problems. Not every noise is a reason for concern, as humming sounds when the unit starts up or a thump when the unit powers down are normal and expected and sometimes the solution to a screeching noise is as simple as adding oil for lubrication. However, if your heat won’t turn on or your unit is making a persistent or odd noise, it could be due to a few different reasons:

  • A loose part
  • A damaged part
  • Debris caught in system
  • A leak
old HVAC system out in the snow

A Part is Loose

            The most common indication of your system having a loose part is continuous thumping noises or scraping and screeching noises. If you hear these kinds of noises, it is possible that the blower fan has come loose, and its blades are now dragging against the other metal inside the system. This also goes for other parts becoming loose as well. Thumping sounds can also mean the ductwork has become loose in the sense that it has spread out and a seal has been broken or a hole in the ductwork has been made. Vibration noises can occur when there are loose screws or parts in the heat pump.

A Part is Damaged

If you are hearing screeching noises coming from your heating unit, the cause of this could be worn out or damaged moving parts such as the fan belt or motor bearings. If the motor bearings become damaged, the motor may move off center and cause this screeching noise you are experiencing. Humming can also indicate the fan is wearing out. Your furnace also may make noises if your compressor needs to be replaced. If the sound you are hearing is more of a thumping, you may have broken compressor springs. Clicking sounds can mean the contactor, which is a part of the HVAC system that is used to flow energy between the thermostat and the compressor unit, is damaged. Simply replacing any of these damaged parts should solve the problem.

There is Debris Caught in the System

            Build up or debris in either your furnace or boiler can be the cause of various noises you may be hearing. Build up of sediment in the water heater could result in some popping or knocking sounds. If these noises become regular, it is a good idea to have the water heater flushed to clean out this debris. If the boiler is whistling it could possibly be the result of a frozen pipe which is causing a blockage. A whistling sound coming from your furnace usually means the air flow is being obstructed in some way. This could be due to clogged or dirty air filters. These can be cleaned and installed, or replaced. Banging noises coming from the furnace could be from clogged or dirty burners. Burners being dirty will decrease efficiency of your symptom, forcing it to use more energy to do the same job it did when they were new. If you do not have your furnace properly cleaned, it can potentially pose health concerns like you and your family getting sick more easily.

There is a Leak

            A hissing sound is typically an indication of a leak in your heating system. In some cases, a leak may also cause a high-pitched whistling noise. Leaks can be either internal or external, but either should be addressed as soon as possible. If the sound is a soft hiss it could just be an air filter that was not properly installed or is the wrong size. If the sound is a loud hiss coming from the furnace it is likely to be a leaking air duct. This will require professional repair.

Highwood Mechanical Can Help!

Although these sounds can offer a good hint towards the issue at hand, determining which problem is going on in your furnace or boiler solely based on the funny noise can be difficult. With over 25 years in business, you can trust Highwood Mechanical to accurately diagnose the problem and take care of it properly so you can breathe healthy, be as energy efficient as possible, and stop stressing about that mysterious noise. Servicing your heating system when needed will prevent long term, more expensive damage and will prolong the life of your system. Contact Highwood Mechanical today for quality service and peace of mind.

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