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Serving the Greater New Braunfels, TX Area

Serving the Greater New Braunfels, TX Area


How a Heating System Can Warn You It’s In Trouble With Sounds


We can imagine that in the future, home heating systems like furnaces will come with complex computer diagnostics that will allow them to identify malfunctions immediately and then alert you to their existence. They may even be able to automatically call your friendly neighborhood heating repair experts—that’s us!—to get the problem fixed ASAP.

But until that technology arrives, you’ll have to use other warning signs from your heater that will tell you it’s time to call us for heating repair in San Antonio, TX. Today, we’re going to look at one specific type of warning, which is unusual sounds.

If you’ve had your heating system for at least one season already, then you know the sort of noises it makes regularly. When you notice something out of the ordinary, it may be a developing repair problem, even if you haven’t noticed any other change in the heater’s performance.

Rattling, Clanging

These sounds often come from loose parts in the heater. It could be screws shaking loose from the vibrations of the unit, a broken part being knocked around inside the blower, or even something as basic as a cabinet door that isn’t latched.

Other possibilities include bent blower fan blades or a loose blower fan belt (on an older heating system). If you can’t find a basic explanation like a loose door, you’ll need to call technicians for repairs. Letting this problem continue will cause extensive damage to the rest of the heater. 

Shrieking, Grinding

These are noises you might hear from either a furnace or a heat pump, and they usually signal the same thing: trouble with a motor. A shrieking sound can mean the bearings in a motor are wearing down; once they wear all the way down, the motor will be in danger of burning out.

Technicians can rescue the motor by replacing the bearings. A grinding noise often means a motor is in the process of burning out, and will probably need to be replaced.


If you hear this sound from a heat pump, it’s the noise of refrigerant gas escaping from a leak. This needs to be corrected soon or it will put the operation of the compressor in jeopardy. If you hear this coming from a gas furnace, it could be a gas leak. Shut off the heater at the furnace switch and call for repairs.


Some clicking sounds are normal at the start-up for both furnaces and heat pumps—but you shouldn’t hear it regularly at other times. Clicking can point to a wide range of different problems, such as dirty motors, stuck gas valves, failing electronic ignition systems, loose wiring, a hard-starting compressor, failing capacitors, and even a cracked heat exchanger in a gas furnace.

This is why you need experts for repairs: we’ll get to the source of the problem so it can be accurately fixed.


This sound from a gas furnace means the burners are probably dirty or the ignition is struggling to come on. The boom is the noise of a build-up of combustion gas igniting at once. You’ll want us on this job right away—but shut the furnace off first! 

Thayer Air Conditioning serves the Greater New Braunfels, TX area. Call us for your heating repair needs—Your comfort is our #1 priority!

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