There are several indications that the heating unit in a house is faulty.
One of the conspicuous indicators is the sounds it emits. Heating systems warn people before they eventually break down, mostly when no repairs are done. Different sounds always signal different things. When the motor is the problem, then the heating unit releases a screeching sound. These sounds are emitted every time the furnace is on and running. Usually, it shows a problem with the motor, bearings, and sometimes the belt. While these are not emergencies that pose health hazards, leaving them unattended could fester into more expensive yet avoidable issues. Loose components in the heater can also trigger rattling sounds. This is an indication that an element or two may be loose and could be rattling against another. There may be a few loose screws in the ducts. Alternatively, there could be a few loose pieces taping down because they hang loosely. In other instances, the sounds are caused by the furnace rattling against the floor. Usually, sounds from the heater are indicative of underlying issues. Even so, it would help if you never were alarmed. Sometimes the sounds mean nothing, especially when the furnace begins to heat up. It could be merely a case of expansion, and the noises will disappear with time. However, if they are persistent even after the heating stabilizes, consider calling a heating repair expert to check if there are any unit issues. In case you are unsure of the sounds and are unable to diagnose them, make sure to call the HVAC technician for a professional assessment and solution.