10 Reasons Your Furnace Is Not Blowing Hot Air
- Thermostat Issues. Sometimes, when your furnace is sending an Arctic chill instead of the heat you crave, it’s not your furnace’s fault at all.
- Filter Issues. There is actually one more user error that could be the source of your cold air issues. ...
- Issues with the High Limit Switch. ...
- Condensate Line Issues. ...
- Problems at the Source. ...
- Outside Air in the Mix. ...
Full Answer
Why furnace not coming on at all?
Sometimes the reason for a furnace not turning on is because it’s simply turned off. Locate the power switch on the furnace itself, which is likely on a nearby wall, or even on a ceiling or floor joist near the unit. It will often look like a regular light switch, but it may or may not be labeled.
Why is my heater not blowing hot air?
Why Your Central Heat is Not Blowing Warm Air
- Faulty Thermostat. Sometimes, the issue with not getting warm air in your home is due to something as simple as a bad thermostat.
- Problem with Your Ducts. You can have a properly working thermostat and furnace and still not feel the heat due to problems with your duct system.
- Faulty Heating Element. ...
- Dirty Air Filters. ...
Why is my furnace blower not running?
Top 6 Reasons (+ Easy Fixes)
- Faulty Blower Motor. The furnace blower motor is what sends warm air from the furnace into your home through the duct system and the vents.
- A Damaged Capacitor. ...
- Loose Furnace Parts. ...
- Damaged Plenum and Ductwork. ...
- A Faulty Transformer. ...
- Dirty Gas Burners. ...
- Incorrectly Adjusted Blower Pilot Light. ...
What to do if your furnace is blowing cold air?
Routine maintenance can prevent future problems.
- Regularly replace air filters. It is recommended to replace filters every 90 days or when the filters appear dirty. ...
- Inspect venting systems and accessory units. Before every heating season, ensure that pipes, humidifiers, electronic air cleaners, and more are secure. ...
- Clean the interior and exterior of the unit. ...
Why is my furnace 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.
How do you fix a furnace that is not heating?
Check that your thermostat has power If it's a battery-powered unit, go ahead and change the batteries, even if it's not dead. If it's not a battery-powered unit, check that the circuit breaker for your thermostat hasn't tripped. If it has, flip the switch and voilà, your thermostat and furnace should be working again.
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.
What do I do if my furnace is blowing cold air?
How To Troubleshoot Furnace Blowing Cold AirStep 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.
Where is the furnace reset button?
Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.
Can I fix my furnace myself?
With a little do-it-yourself experience, you can troubleshoot and repair your furnace yourself. Your best bet though, is to have a maintenance check list for your heating system to avoid the problem.
Why is cold air blowing when the heat is on in my house?
When a furnace only blows cold air, there's a chance the heater could have overheated. But don't worry, this usually doesn't mean the unit is broken. When the system overheats, there's a safety feature that shuts the system off. This is a good thing—it could prevent a fire, carbon monoxide leak, or even an explosion.
Why is cold air coming out of my vents when the heat is on?
This issue could be caused by an improper thermostat setting. Check that the fan blower switch is set to “auto” and not “on.” When the “auto” setting is chosen, the fan will only run during a heating cycle and won't push air that feels cooler through the vents in between cycles.
Why does it feel like cold air when heat is on?
Your body temperature is around 98.6°F (everyone's body temperature is slightly different, but that's the average). Since heat pumps produce air that's below that, it can feel cold to you.
Can a dirty furnace filter cause no heat?
Perhaps the most significant damage a clogged air filter can do to your home is the havoc it wreaks on your furnace. A dirty filter can prevent your furnace from heating your home.
How do I get my heat to kick on?
You should first make sure that the thermostat is switched to the heating function. Next, make sure that the temperature that you have the thermostat set on is lower than the temperature in the home. You may also have an internal problem with your thermostat, which needs to be repaired by a professional.
Why is my furnace not responding to thermostat?
When a furnace is not responding to a thermostat, there is either a problem with the heating unit or the actual thermostat. Lack of power to the thermostat, wrong settings, and outdated software might be to blame, as well as faulty wiring, a tripped breaker, and a dirty furnace filter.
Why is my heat blowing cold air?
When a furnace only blows cold air, there's a chance the heater could have overheated. But don't worry, this usually doesn't mean the unit is broken. When the system overheats, there's a safety feature that shuts the system off. This is a good thing—it could prevent a fire, carbon monoxide leak, or even an explosion.
Why does my furnace blow when it is not putting out warm air?
If the furnace heats up just fine but continuously blows even when it is not putting out warm air there can be a problem with your limit switch. Swapping out the limit switch should only be done by someone who knows what they are doing. If your furnace does not heat up enough you might have an ignition or pilot issue.
Why is my furnace not working?
The most common problems with furnaces deal with thermostats that don’t work correctly and filters. Filters must be replaced often in order for the furnace to operate properly. If you don’t, you are making your furnace work much harder.
How to fix a furnace that is blowing cold air?
1. The Furnace Is Blowing Cold Air. First, check to make sure the thermostat is set correctly. You will want to make sure that the fan control is set to auto, and not ‘on’. If the thermostat appears set correctly, turn off your heater at the thermostat and check the filter. If the filter is dirty, replace it. ...
How to deal with furnace problems?
While most problems are fairly easy to deal with, even those can be a big hassle without the proper knowledge. Contacting an HVAC repair person is usually the best idea to deal with furnace issues. Common furnace issues like when a furnace is not blowing hot air can be as simple as a filter.
Why does my furnace keep turning on and off?
If your furnace cycles a lot between on and off, check the filter. These conditions are most often caused by thermostats and filters. Make sure that airflow into your furnace is not blocked or limited.
What to do if your furnace filter is dirty?
If the filter is dirty, replace it. If the filter is not dirty, move on to the furnace itself. If you have an older furnace you can check the pilot light. For a newer furnace, it will use an electric ignition instead. At this point, you can try to relight the pilot light.
What to do if your furnace is off?
If this is the case, turn the furnace back on. If the furnace has power, then open the side of the furnace up. Some furnaces will have a reset switch that may have got flipped. If they do, research your model and try to hit the reset button.
Why is my furnace not blowing hard enough?
Furnace Not Blowing Hard Enough. If the furnace blowers are generating heat in insufficient quantities, the issue is likely due to either a dirty motor or a loose blower belt. The motor can accumulate dirt over time and the gradual buildup can wear down the system.
Why does my furnace blow cold air?
Simply put, if the settings on your furna ce system are not properly coordinated with the fan, the latter will blow irrespective of whether you need or want actual heat.
What happens if a furnace breaker is off?
For example, if the circuit breaker to the furnace is off, the furnace will not generate heat. Likewise, if the circuit breaker to the blower fan is off, warmth will not be spread from the heating coils. If tripped, circuit breakers should not be tested more than once. An issue of repeat tripping should be reported to an HVAC service person ...
Why does my furnace not heat?
If you feel no heat in the minutes after you activate your furnace, something could be wrong with the belt, heating coils or furnace settings. If the blowing mechanisms are inconsistent or non-functioning, there is probably an issue with the blower belt. If the blowers are working as normal but you feel no heat, the issue is probably due to the temperature settings or heating coils. The settings can easily be adjusted if you need to test the performance of the furnace but an issue with the heating coils will necessitate a call to your nearby HVAC service specialist.
What temperature does a furnace shut off?
For example, if you have your furnace set to 70 degrees Fahrenheit, the furnace will shut off the heating coils once the ducts sense an ambient room temperature of 70 degrees Fahrenheit, but the fan will continue to blow cold air if it is set to “on” instead of “auto.”.
How to test if blower fan is working?
You can test the blower fan by turning off the heat — or, depending on your system, setting the thermostat to “fan only” mode — and switching the fan from “auto” to “on.”. Wait for a few minutes to see whether any fan breeze comes forth.
How to tell if furnace is in trouble?
How to Tell If Your Furnace Is in Trouble. If your furnace is on but no heat is coming forth, the problem could stem from issues with your thermostat. If your furnace is not blowing heat or even seeming to activate, you have a more serious problem at hand. Watch for the following tell-tale signs of furnace trouble:
Why is my furnace blowing out cool air?
If your furnace is blowing out cool air, this is a likely cause of it. First, check to see if your airflow is “too good.”. If a stiff breeze disables your heater, that means you likely have an exposed firebox.
Why does my furnace not go anywhere?
Improper ducting can also cause the warm, moist air from your furnace not to go anywhere. As a result, built-up condensation will overpower the condensate line and short out your furnace. This situation typically requires a specialist to come to look at your vents.
What happens if the heater is not igniting?
If the heater is not igniting, you may have to replace it. If you do replace it, be sure to avoid touching the igniter with bare hands. The oil on human hands is flammable, which will reduce the shelf life of your igniter. If the pilot light doesn’t stay lit, that may be a sign of the thermocouple going out.
Why is my furnace not responding to temperature?
If your furnace is non-responsive to changes in temperature, you likely have a thermostat error. Given that this is an electronic issue, this brings up an entirely new line of troubleshooting steps. Follow this quick set of troubleshooting steps if you believe this is a potential issue:
What causes a furnace to go bad?
Sometimes, you have to recognize when parts of your furnace are going bad. When it comes to moving hot air, one of the more common issues come from the blower motor. The blower motor controls the fan, which pushes the air throughout your ducting system.
How to tell if thermocouple is corroded?
Look to see if any gas valves look rusted or corroded. If they do, it will be time for a replacement. If they don’t, you will need to contact an HVAC technician to address further concerns. If the fire starts but doesn’t maintain, it is a sign of your thermocouple not working. Don’t immediately jump to a replacement though, try and adjust it using a wrench first.
What does it mean when your furnace stops cycling?
Short cycling (stopping as soon as it starts) High energy bills. If your furnace is older, this typically means that it is time for you to replace it. If your furnace is newer, check online to see if this is a common issue. Otherwise, whoever hooked the heater may have done so improperly.
Why does my furnace blow warm air?
If your furnace is blowing warm air and not hot air, this could be due to your thermostat regulating the temperature in your home. However, there are other reasons why this occurs such as dirty vents, outside air in your vents, poor furnace performance, and having the wrong size furnace for your home.
Why does my furnace feel warm?
The most common reason why the air feels warm rather than hot deals with a hole in the air vents that carry the air out of the furnace. If you notice warm air only hitting one of your rooms, check the vents nearby for holes and patch up any you see.
How Do You Know If Your Furnace Is Doing Its Job?
Thermostats are programmed to signal when HVAC systems should blow out warm air instead of hot as a way of maintaining a steady temperature.
How to tell if furnace is overheating?
Run a quick diagnostic to see if your furnace is overheating. If your furnace is overheating, the breaker inside will trip to prevent an explosion. Should your furnace struggle with this issue, call an HVAC tech immediately. This is a potentially dangerous issue that needs to be addressed.
How to troubleshoot a furnace?
The best way to troubleshoot this is to take out your furnace’s filters and clean them. If the airflow now feels a lot hotter, congrats! You solved the problem.
Why does my thermostat stop regulating heat?
Double-check your thermostat’s batteries. This could be a low battery issue. Some thermostats stop regulating heat if they don’t have enough power.
Why is HVAC important?
Your home’s HVAC system is one of the most important systems when it comes to your safety, your comfort, as well as your home’s value. That’s why minor issues with your heating system still deserve a lot of attention, even if it’s something that is as simple as a furnace that’s blowing warm air rather than hot air. Speaking of, what does that even mean?
Is Your Furnace Not Heating or Blowing Warm Air? - Here's What To Do
Furnaces (or commonly referred to as heaters) are used as a major component of a central heating or HVAC system. Furnaces are permanently installed to provide heat to an interior space through intermediary fluid movement, which may be air, steam, or hot water.
How a Gas Furnace Works
The heat capacity of a gas furnace is measured in British Thermal Units (BTUs). A BTU equals the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Essentially, a furnace creates a cycle of warming cooler air through a few simple steps.
Furnace is Blowing Cold Air & Not Warm Air
When it dips below freezing, the last thing you would want is for your furnace to be blowing cold air out of your home’s vents. First, make sure that your gas bill is paid & not turned off. If there are no issues with your natural gas supply, the next step would be to check your thermostat.
Check Air Filter
Next, it would be wise to check your air filter. This is one of the most common problems with HVAC systems failing to heat or cool properly. If your filter is dirty, then it is time to replace it! Turn off your unit while you replace your filter, then turn it back on & wait a while to see if this resolves your problem.
Check Furnace Pilot Light
Another common reason for your furnace to be blowing cold air instead of warm air is due to the pilot light being out. In older furnaces, this is a flame that stays lit, but newer systems use an electric ignition.
Call Your Local Heating & Air Professionals
If you have tried the above steps, and your furnace is still not working, then it might be time to call the professionals! Paschal Air, Plumbing & Electric is local, experienced, and ready to help you tackle your furnace problems. Contact us today or give us a call at 479-751-0195.
1. Dirty Air Filters
You’ll come across “dirty air filters” a lot when troubleshooting furnaces, and for a good reason. Dirty filters put a lot of strain on the furnace, typically causing the furnace to work harder and consequently increasing your heating bills. Unfortunately, the same dirty filters can also cause a weak airflow at the supply vents.
2. Overly Efficient Filters
You may have realized that furnace filters are rated in MERV – short for Minimum Efficiency Reporting Value. MERV ratings range from 1-16. The higher the rating, the tinier the pores through the filter.
3. Poorly Installed or Ineffective Ducts Runs
If you’ve heard HVAC professionals warning users about the dangers of running or troubleshooting the ductwork yourself, this is one of them (besides safety concerns).
4. Leaky Ducts
Besides installation and repairs, you must also keep an eye out for duct leaks. According to the Department of Energy, over 90% of homes in the US have leaky ducts that cause expensive heat loss, usually resulting in inefficient heating and high energy bills.
6. Your Vents are Undersized or Ducts Oversized
Have you ever wondered why they can’t just have large pipes delivering heat to your home, why all duct pipes are tiny? The reason is static pressure. The warm air must be kept under pressure.
7. The Vents are Dirty or Blocked
If the vents are of the right size, you may want to check if they are blocked or dirty. Remember that the furnace blower fan pulls cold air into the furnace at speed. Therefore, any large debris in the air is usually held back at the vents. Thus, you might find twigs, leaves, hair, etc., blocking the vent.
8. Blower Motor Malfunction
The furnace primarily relies on the internal blower fan to maintain air circulation within the furnace and throughout the home.
