Is Your Heating System Too Loud? Cycling On and Off? We Can Fix That

Your home heating system should run fairly quietly when it is operating correctly. The only types of noises you should hear are the movement of air out of ducts and possibly a clicking sound at the thermostat signaling the unit to turn on and shut off at the end of the heat cycle.

Unless you are right next to the furnace, you should not hear the actual sounds of the furnace running. If you can hear the sound of the blower motor, blower motor fan, or other types of noises throughout the home, it could indicate something is wrong with your furnace.

Troubleshooting the cause of the noises will depend on the type of system installed in your home. Let’s take a look at some of the various systems and common causes of noises.

Radiator/Radiant Heating Systems

These types of systems use hot water to deliver heat to the rooms in your home. Newer designs allow for radiant heat systems to be installed under flooring without the need for a radiator in each room.

In order to transport the hot water through the system, various plumbing pipes are used, similar to your water pipes. These systems can produce banging or knocking sounds when there are no air relief valves attached to the water lines or the pipes are not secure in the walls or subflooring.

When the flow of the hot water is abruptly stopped when the system shuts off and there are no pockets of air in the relief valves, it “hammers” against the side of the pipes from the reverse flow.

To illustrate, think about a vehicle crash test into a solid steel wall. Upon impact, the car hits the wall and the force of the impact causes it to move backward. The same is true when the water in the radiant heat system shuts off and the pressure cannot be released through air relief valves.

In cases where you hear a constant banging while the system is in operation in different areas throughout the home, this signifies the pipes were not properly secured when they were installed. The pipes can bang against interior structures and cause an echo effect.

Aside from banging, other noises you could notice include hissing sounds and cracking and popping sounds. Hissing sounds are caused when there is a restriction in the pipes, like from scale buildup, where the water flow has to pass through a narrow section. Cracking and popping sounds occur when there are instances of scale buildup, corrosion, and any other sediments in the hot water or boiler tank.

Resolving these problems is not difficult as long as you get help from a qualified and experienced plumbing and heating repair company. The reason we recommend using a professional is that working with hot water lines can be dangerous and could result in personal injuries from the hot scalding water.

Conventional Furnace Systems

These types of systems are where you have the furnace installed somewhere inside the home, like your garage or basement, and it is connected to your outdoor AC condensing unit. Most people refer to this type of system as central heating and air conditioning.

Some of the more common noises you might hear from a conventional furnace system could include:

• Hissing – Hissing noises can occur when there is a restriction or blockage in the ductwork and the air is being forced around it.
• Clicking – If you notice clicking noises coming from the furnace unit, it could mean many different things, such as certain components are not engaging when they should and the relay switches keep clicking attempting to turn them on or off.
• Cracking and Popping – Cracking and popping noises could emit from your furnace if the heat exchanger or heating element inside the unit is damaged or cracked.
• Banging – Banging can occur if parts and components are loose, like the blower motor fan blades banging against the inside of the unit because they are no longer securely attached.

Packaged Heating and Cooling Systems

Packaged systems are all-in-one units that are installed outside the house. They provide both heat and air conditioning for the entire home. These types of systems are very popular in southern areas of Texas where it does not get that cold in the winter.

It can be harder to notice sounds coming from packaged systems inside the home. However, if you notice the unit seems a bit louder, and you can hear it turn on and off, hear the fan, or other sounds from inside the home, then there could be problems that require an inspection from a cooling and heating system technician.

Other Types of Heating Problems

Aside from making noises, there are other problems that can occur when firing up your heater for the first time. Initially, you might notice a burning smell coming from the air vents in your home with conventional and packaged systems.

This is normal and should dissipate after one or two cycles. If the smell persists for more than two cycles, then there is a serious and potentially dangerous problem with the system. Shut it off immediately and call for emergency service right away.

If you have a gas furnace, and you notice the thermostat clicks but nothing happens, the pilot light might have gone out. No pilot light—no heat. However, do take caution when checking the furnace, as gas will still continue to come out.

If the pilot is out, shut it off, open and air out the room, and wait an hour before attempting to relight the pilot. If the pilot continues to go out after being lit, this is when it is time to call in a professional.

Other common problems have to do with the cycling on and off of the system. There is a variety of different issues based on the type of system you have installed in your home, but could include:

• Blower motor fan continues to run even after the unit has cycled on and off.
• Blower motor fan does not engage during the furnace cycle.
• The blower motor turns on before the furnace does.
• The furnace cycles continuously and never shuts
• The furnace cycles on and off almost constantly with only a minute or two between cycles.
• The furnace only runs for a few minutes and shuts off before reaching the preset temperature on the thermostat.
• The thermostat clicks to signal the furnace to turn on, but it never does.

Troubleshooting these types of problems can be very complex because they could involve electrical systems, electrical wiring, natural gas lines, pilot systems, plumbing systems, and more.

In some cases, the problem could be as simple as a broken or loose wire that needs to be fixed and reattached to the right connection on the thermostat. Other times, the problem could be due to the age of the system and various parts and components wearing out.

As such, it is in your best interests and safety to contact a professional plumbing and heating technician to troubleshoot and diagnose what is wrong with your home’s heating and cooling system.

• TIP: To avoid unexpected heater failures and emergency service calls, schedule bi-annual heating and cooling maintenance services with your professional technician in the fall and spring. The spring service inspects and verifies your AC is ready for the hot Texas summers, while the fall service inspects your furnace to ensure it will provide heat on those colder winter mornings.

For problems with your home’s heating system or to schedule maintenance service, please feel free to contact your nearest Christianson Air Conditioning and Plumbing location in Austin, New Braunfels, Temple, or San Antonio today!