How to Troubleshoot Uneven Heating in Multi-Story Homes

Heating services in Charlotte, NC

When functioning properly, ducted heating systems should distribute heat evenly throughout your home. Something is wrong if you notice hot and cold spots in different rooms. Unfortunately, this could occur for several reasons, making troubleshooting a bit tricky. Here are some steps you can take to help identify the issue.

Begin With Your HVAC Air Filter

Uneven heating in a home often happens when there are airflow issues within the heating system. A common culprit is a clogged HVAC air filter, which can decrease the air pressure leaving your heating system and result in certain rooms receiving less heat. Therefore, the first troubleshooting step is to check your HVAC air filter.

If the filter looks dirty, replace it with one of the same size, thickness, and MERV rating. Additionally, ensure your filter does not have a MERV rating higher than 13, as most residential HVAC systems face noticeable airflow issues beyond that threshold. If your filter seems clean but hasn’t been changed in over three months, replace it anyway, since that’s the average replacement interval for most HVAC systems.

Examine Your Air Registers

The next thing to check is the air registers in your home. Ideally, every vent connected to your ductwork should remain open, as the design of your ductwork relies on this to ensure sufficient airflow. If too many vents are closed, the pressure in your ducts will rise, causing backpressure that can wear out your HVAC blower motor more quickly. Additionally, this can restrict the amount of hot air that reaches each room. If necessary, you may partially close a few vents to adjust the temperatures in individual rooms. However, avoid fully closing any vents and limit any semi-closed vents to no more than two or three.

Check Your Thermostat’s Temperature Readings

Another issue that can lead to uneven heating is inaccurate thermostat readings. For instance, if your thermostat perceives the temperature to be higher than it actually is, it might shut off your HVAC system too soon. This may result in some rooms being significantly colder than you expect. Use a standard glass or digital thermometer to check your thermostat’s accuracy. Position one near the thermostat and allow it to sit for at least 20 minutes. By the end of that time, the two devices should show nearly the same temperatures. If there’s a difference of more than a degree or two, your thermostat might require recalibration or replacement. Alternatively, you can also use a temperature gun and point it near a vent and match it to what the thermostat says it should be.

Look for Slipped Dampers

Most residential HVAC ductwork systems include separate branches that serve different areas of the home. In multistory houses, it’s common for each floor to have its own supply branch. This configuration gives designers control over the airflow distribution to each floor. In this setup, a damper should be installed in each branch. Typically, you can find the levers that operate these dampers near the points where the branches split from the HVAC system.

Dampers that slip out of position can cause uneven heating in multistory homes. If you can locate the levers that control your home’s dampers, check their position. It’s unusual for branch dampers to be closed beyond half-way. This would indicate deficiencies in the ductwork’s design or an HVAC system that is not suited for the ductwork. Adjusting your ductwork’s dampers may help your home heat more evenly.

Have Your HVAC Inspected

Finally, various issues with your HVAC system can lead to uneven heating in a multistory home. One common culprit is a malfunctioning blower fan. Your HVAC blower fan needs to generate enough pressure to push warm air into every corner of your home. If it’s not accomplishing that, you’ll experience uneven heating. A simple problem like a worn-out drive belt can be the cause. Additionally, the fan’s motor itself may require replacement. If you inherited your HVAC system from a previous owner, consider the possibility of a settings issue. For instance, your HVAC blower might need adjustments to its speed setting.

Your Trusted Home Heating Experts

For over 35 years, Integrity Heating & Cooling has been the HVAC service provider that homeowners in Charlotte, NC, trust the most. We offer services in air conditioning, heating, indoor air quality, and ductwork. Every job comes with a 100% satisfaction guarantee, and we are accredited by the Better Business Bureau with an A+ rating. If you’re experiencing uneven heating in your Charlotte home, call Integrity Heating & Cooling today!

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