Low Refrigerant LevelsIf your refrigerant levels are low, you may notice low or no air blowing through the vents as well as reduced cooling throughout your home.
If your heat pump is on but not blowing hot air, it could be due to a dirty air filter, low refrigerant levels, or a malfunctioning thermostat. The outdoor unit may also be iced over, or the reversing valve may not be working properly. Contact a professional for further inspection.
Obstructed Vent
Furniture, bedding, and the vent damper could all be possible obstacles to the vent. If you find any closed or blocked vents, you can clear away the obstruction and feel for airflow, but if your vents are open and still not blowing enough air, there could be an issue with the fan's motor.
If your AC unit and furnace fan is running but you still have no airflow your most likely have a frozen evaporator coil. Caused by either an airflow issue like plugged air filter or plugged evaporator coil. Or your AC unit could have a refrigerant leak and be low on charge.
If the airflow is stopping and not switching to another vent, but the blower is still heard, then it is likely that there is an issue with the fan blades separating from the motor. If this is the case, then the blower motor assembly will need to be replaced. Does this make sense?
A dirty or clogged air filter is one of the most common culprits for a furnace running without blowing air.
First, make sure the register damper is open. Then remove the register cover and check for visible dust and debris clogging the duct. It's also a good idea to check your AC filter and see if it's clogged with dust. If so, get a new filter and replace it.
While furnaces can stop operating for complicated reasons, home owners should check a few usual suspects first behind a lack of hot blowing air: Electrical problems causing a loss of power. Blocked air vents and ducts restricting airflow. Improperly configured thermostat settings.
You can generally identify a blocked air duct by a distinct drop in heating and cooling efficiency, increased energy costs, and occasionally a musty, dusty smell throughout the home. The blockage usually comes over time, by a buildup of dust and debris that just accumulates until it begins choking the system.
If your HVAC system is blocked up or clogged somewhere, your AC won't send enough cool air through the vents when it's running. A fan problem can also cause this issue. Or, you can end up with that problem if you don't address the circulation issues. It's not always easy to realize a circulation problem in the summer.
Check the air filter and replace the filter if it's dirty. Look for dirt clogging the condenser fins on the outside unit and clean the fins if necessary. Check for a clogged condensate drain line and clear the clog if condensate water isn't draining from the unit.
The most common problems that cause a lack of airflow include frozen coils, broken fan and restricted airflow due to dirty air filters or vent obstruction. However, there are many other issues that can lead to minimal airflow, so it may be necessary to ask the professionals.
Begin by turning the power off to the heat pump. You will need to reset both units by pressing the buttons or flipping the switches. If your heat pump does not have a reset button, it will have a power switch. Turn the switch off, wait for two to three minutes, then turn the switch on again.
Heat pump airflow can be increased by cleaning your heating and cooling system's evaporator coil, which is usually taken care of during routine maintenance visits from your contractor. Your technician may also adjust the heat pump's fan speed during preventive maintenance to improve air circulation.
Limited Return Air
You will want to check and ensure that the return vents throughout your vent are not blocked. If these vents are blocked, it can lead to a lack of air being pulled back into your system.
An anemometer, a test instrument that measures air velocity is used to determine the average airspeed in the duct. Then the average feet per minute is multiplied by the area of the duct in square feet to determine the airflow moving through the duct.
Try changing the filter and cleaning the outside unit first. If that does not work, you most likely need a technician's help. While low refrigerant may be the issue, it could be other technical issues as well, like a malfunctioning compressor or reversing valve.
Check Your Furnace Air Filter
Next, check your heater's air filter, as this can cause a furnace to stop blowing air. Your filter could be so saturated with dust and debris. In that case, even though the furnace is actually blowing air, your clogged filter is blocking it from making it into your ducts.
If the filter is clogged, replace or clean it immediately, then rerun the furnace. If this does not correct the airflow issue, make the call for help, as it's likely an issue with an internal component, such as the blower or control board, that will require an experienced technician to diagnose and repair.
In AC systems, the air conditioner reset button is on the outside unit's lower edge, typically close to the ground. Some models have the reset button located behind the service panel, which may require tools to remove. Reset buttons are usually red or yellow with a clear “reset” label.
If your AC is running but not cooling, it could be due to a dirty air filter, incorrect thermostat settings, a malfunctioning thermostat, a refrigerant leak, dirty condenser coils, blocked vents or ducts, a faulty compressor, frozen evaporator coils, or electrical issues.