Simply put, the furnace inside the equipment needs to get heated up for the fan to emit warm air. If the furnace is cold, it cannot heat the air being propelled outside. You can fix this by setting your blower to ‘auto’ so that your fan only works when the furnace is hot.
How do I stop my heater from blowing cold air?
How To Troubleshoot Furnace Blowing Cold Air
- Step 1: Check Thermostat Setting. First and most importantly, make sure your thermostat is set to Heating Mode. …
- Step 2: Evaluate and Adjust Your Vents: …
- Step 3: Assess Furnace Filters and Replace Filters If They Are Dirty. …
- Step 4: Call An HVAC Pro.
Why is my heater suddenly blowing cold air?
Your furnace may be blowing cold air because the filter is too dirty. A dirty air filter blocks airflow over the furnace’s heat exchanger, causing it to overheat. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack.
Why is my heater running but no heat?
Dirty filters are the most common cause of furnace problems. Dust and dirt restrict airflow—and if the filter gets too clogged, the heat exchanger will overheat and shut off too quickly, and your house won’t warm up. If the blower is running but no heat is coming out, replace the filter.
Why does my heat feel like cold air?
The system is in a defrost cycle
This transfer of warm air to your outdoor unit helps to melt any ice on your outdoor unit. When this happens, your heat pump is essentially in “cooling mode,” which is why you may feel cold air coming from your vents.
Why is my heater blowing cold air in my truck?
This can be due to a choked cabin air filter, a failed thermostat valve, or a faulty heater core. How do I fix a car heater blowing cold air? Start by changing the cabin air filter, and if that doesn’t work, replace the thermostat valve. If that doesn’t do it, change the heater core.
How do I reset the heater in my house?
How to Reset an Electric Furnace
- First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
- Locate the reset button on the furnace and press it to reset the furnace. …
- If the button is popped up, press it down.
- Return the cover to the blower compartment and turn the power on.
How do I reset my thermostat?
Reset the Thermostat
The method to reset your thermostat will vary depending on the model. Common methods for resetting a thermostat include installing the battery backward for five seconds, pushing a recessed reset button with a pin or paper clip, or shutting off the breaker to the thermostat for 30 seconds.
Why isnt my heat working in my house?
Often, the issue is that the heating system is simply dirty. … The system’s heat exchanger cannot work unless there’s sufficient air moving across it to stop it from overheating. In short, a dirty blower can cause the heat exchanger to fail. Dirty air filters could also be the reason your heater stopped working.
Why is my heat not coming through the vents?
When you turn the furnace on but no heat comes out, there may be an obstruction. Dirty air filters restrict airflow, which can make it feel like not much heated air is coming out of your vents. Check the furnace filter and replace it if its surface is covered with contaminants.
Why is there no air coming from vents in my house?
The most common cause of low air flow through the vents in your home is blocked or dirty AC filters. … Be sure to keep the area around your AC filters clear of furniture and anything else that might block the flow of air, and be sure to clean or change your AC filters once a month.
Why are my vents not blowing hot air?
Four common reasons there isn’t enough hot air blowing out of your vents are: A Vent is Blocked. The Air Filter is Clogged. Leaky Ductwork.