Uneven Heating? Check for These Common Causes

Uneven or inconsistent heating can be a difficult problem to trace back to its source. If you notice that rooms or spaces are warmer than the rest of your home, it’s a good idea to start checking your HVAC system for signs of trouble. Sometimes the root of the problem is a malfunctioning component, while other cases are a result of the heat escaping somewhere else.

Whether you need furnace repair in Denver or furnace installation in Denver, our HVAC company can help. Professional heating and cooling technicians from Lakeside Heating & Air Conditioning can determine what’s causing uneven heat, taking steps to repair or replace the affected parts of your HVAC system. We can also help you get started by sharing the most common causes of uneven heating.

1. Ductwork

Uneven heating is often a symptom of an issue somewhere along the duct system. Your home’s heat doesn’t always make it to each room at the same rate, which can result in different temperatures throughout the home.

Blocked ducts

Ducts become blocked in two ways — either a register or return vent is closed somewhere, or debris has collected in the ductwork and is blocking airflow. First, check every vent opening in the house and make sure they’re open. If furniture or curtains are close to the air vent, they can also block airflow. After ensuring all the vents are opened, schedule an inspection for your ductwork if you believe there’s still a blockage somewhere.

Air leaks

Leaks in the ductwork waste money and energy by allowing heat to escape into the walls, attic and other unfinished parts of your home. Leaks can also frequently be found where the ducts run through the basement. A comprehensive inspection by a professional technician can pinpoint the location of leaks so that you can have them properly sealed and insulated against heat loss.

Inadequate insulation

Did you know that many homes lack adequate insulation? Installing more insulation in your home can reduce heat loss by giving airflow fewer places to escape. Additional insulation can also improve your HVAC system’s overall energy efficiency, which means reducing your monthly heating bill.

Poor duct layout

The route your ductwork takes through your home can have an effect on how efficiently air circulates from room to room. A poor layout can be made worse when renovations or new additions are made to the house, especially if the layout for any new ductwork doesn’t take the rest of the house into account.

2. Thermostat

Sometimes your furnace is in good working order, and it’s the thermostat causing the problem. A few simpler thermostat issues can be fixed, but others involve failed electrical components that must be replaced.

Incorrect calibration

Thermostats may need periodic calibration to ensure the device is properly monitoring the indoor temperature. You can check your thermostat’s calibration by placing a glass thermometer next to the thermostat for 15 minutes. If the reading on the thermometer matches that on the thermostat, then everything is properly calibrated. If not, your thermostat will need to be re-calibrated before it will correctly gauge the temperature.


A variety of components can fail or malfunction, leaving the thermostat unable to properly communicate with your HVAC system. If you’ve noticed inaccurate readings, try recalibrating the thermostat first. If the problem persists, or if the furnace isn’t generating the correct amount of heat, it may be time to replace the thermostat.

3. Zoning System

A quality zoning system lets you separate your home into separate comfort “zones” with their own temperature. For example, a zoning system would make it easier to keep bedrooms on the second floor cooler than the rest of your house.

When these zoning systems malfunction, your home’s different comfort zones can turn into hot and cold spots. Keeping the zoning system in good condition will prevent your preferred temperatures from fluctuating.

4. Furnace

Problems with the unit itself are generally more severe than minor thermostat or duct repairs. Furnace-level problems could lead to replacing the system entirely, as repair won’t be possible or cost efficient.

Incorrect sizing

Each furnace’s output of heat is measured in BTUs. Generally, you can determine what size of furnace you need by multiplying your home’s square footage by 30. The resulting number is how many BTUs your furnace should provide. If your furnace has a lower BTU output, it could be why it can only provide uneven heating. Upgrading to a properly sized unit will ensure your home is heated more quickly and efficiently.

Blower motor malfunction

The blower motor is an important component that creates airflow, sending heat from the furnace into your ductwork. When the blower motor malfunctions, it can create inconsistent circulation by stopping and starting. This uneven airflow results in uneven heating.

Dirty air filters

Your air filters stop duct, dirt, mold and other airborne contaminants from accumulating inside your HVAC system. But if these filters aren’t regularly cleaned or replaced, the clogs form on the filters themselves. Make sure to swap out or wash your furnace’s air filters every few months.

System failure

A myriad of reasons can cause the unit to fail. Some problems, like a poorly functioning ignition or a malfunctioning blower, may only require repair or replacement of the specific component.

Other issues such as a cracked heat exchanger or malfunctioning control board are more severe. They are so expensive and time consuming to repair that oftentimes a new furnace is still a more cost-effective choice. A full inspection can determine if you need HVAC repair in Denver or if HVAC installation in Denver is the correct option.

Call Lakeside for Fast Furnace Repair Solutions

The expert technicians at Lakeside Heating & Air Conditioning are ready to help you diagnose and resolve your uneven heating problem. For trusted heating and cooling repair in Denver, give us a call at 303-412-8015 today. If it’s time to upgrade your system and you’re looking for something more energy efficient, ask us about our heat pump installation in Denver and mini-split installation in Denver.