Incorrect thermostat setting. If your heater is blowing cold air, and it’s not one of the first two possible explanations on this list, then you’ll need a specialist to at least come and take a look. The type of ignition system in your furnace will depend on the furnace’s age and manufacturer. Active 2 years, 7 months ago. 5 reasons why your furnace might start bowing cold air 1. Dirt and debris can collect on the valve, causing it to shut down. Your Furnace Air Filter is Dirty Privacy Policy. After all, a furnace shouldn’t be blowing cold air, right? To troubleshoot a misbehaving gas furnace, start with the easiest explanations and solutions, then work your way to the most complicated. There are two possible routes here, one of which many homeowners who are new to heat pump systems encounter. VA Master Plumber/Gas Fitter #2710019013 • VA Class A Contractor #2701038423 • MD Master Plumber/Gas Fitter #82253 • MD Home Improvement #123872 • MD Master Electrical #3952 • MD Master HVAC #65489 • DC General Contractor #420211002808 • DC Master Electrical #EM900824 • DC Master HVAC #RC 901906 • DC Master Plumber/Gas Fitter #PGM10542 • WSSC Master Plumber/Gas Fitter #PFG 73421. By switching the thermostat to “auto,” the fan will only blow when the furnace is heating the air. Inadequate gas supply. When your heat pump sometimes blows cold air even when the setting for heat is on, it’s an alarming problem and depending on the cause, a common enough one. If your forced-air gas furnace is blowing cold air, a number of factors could be to blame—many of which you can address on your own, without the immediate help of a service professional. Ensure that your thermostat is set higher than the temperature in your home. Possible Conclusion 1: It’s … This type of heating is highly inefficient. A dirty air filter will restrict airflow to your furnace and can cause it to overheat. Your body temperature is around 98.6°F (everyone’s body temperature is slightly different, but that’s the average). When air blows over the coils, the air picks up that heat. Two thermostat issues that could cause your furnace to blow cold air include: Your thermostat is still set to COOL not HEAT Your thermostat fan setting is set to ON not AUTO Sometimes snow, ice or other debris can clog the system and either shut your system down or force it to blow cold air. You may also see an error message on your thermostat, or a blinking LED light on the furnace control board. Design and Marketing by LeadsNearby. Or, the valve could simply be worn out. It’s important to have a professional do cleaning and maintenance on your furnace annually, to ensure that the problems you may come to face are minimal. This is another reason to have your system checked regularly. So if you’re experiencing furnace issues, give us a call. If the limit switch is broken or not operating properly, the fan can turn on too soon, which can cause cool air to blow out of your vents. A dirty air filter can block airflow over your furnace’s heat exchanger, which can cause it to overheat. 415-821-0560 | How have you & your family been feeling? When the furnace overheats, the heat exchanger becomes abnormally hot. Cold air trapped inside will need to be expelled before the hot air can take its place! But as it turns out, this is a furnace problem that comes up often in many Bay Area homes. We're sorry, but it looks like we don't offer service to this zip code. Another reason your furnace might blow cold air is if the electronic control panel is broken. Below are some reasons you may be getting a blast of chilly air and how you can warm up your house as soon 1as possible. When it’s cold outside, the last thing you want to find is cold air coming out of your furnace when it’s supposed to be heating your home. Click here for a guide on how to fix this problem. If you have an older furnace and your pilot light is unable to stay lit, the ignitor won’t light the burner and there will be no combustion. However, the fan will keep running, cooling the furnace to protect it from potential damage. Cabrillo Plumbing, Heating and Cooling ©document.write(new Date().getFullYear()) | All Rights Reserved | If they’re not, try changing the batteries. Unfortunately, this is not a problem you can fix on your own. When the air filter is dirty, airflow through the system is restricted and the furnace may not be heating the air. For Furnace … Does your blower turn on & off frequently or does it blow cold air sometimes? Your furnace’s fan is controlled by a limit switch which tells it when to turn on and off. This time of year, especially when it gets cold outside in the evenings, we get many calls from homeowners concerned that there is cold air blowing out of the duct registers in their home when their heat is running. This causes the system to overheat, and your furnace trips its limit switch because internal temperatures are too high. 13 reasons your furnace is blowing cold air 1. A dirty air filter is a common culprit of furnaces blowing cold air. Check The Thermostat. Furnaces can overheat for a variety of reasons, including: If you’ve already checked your air filter and you know it’s not the source of the problem, you’ll need to contact a professional for a furnace inspection.. Called a “dual-fuel system”, the gas furnace kicks on when the heat pump can no longer efficiently pull heat from the cold air outside. 1.Your Heater hasn’t had time to warm up. After you check your thermostat, it’s time to check your air filter. When you turn on a faucet to receive hot water, you often have to wait a bit... 2. The hot and cold air pattern might happen for an extended period, and still, your house remains cold. One of the most common causes of a furnace blowing cold air is not actually a repair at all. 7. Is the furnace’s blower constantly running? Sometimes, the heat exchanger can get too hot and overheat. If your furnace is blowing cold air, give us a call today! When set to ON, your furnace will deliver air 24/7, even in between heating cycles. If you have leaks or holes in your air ducts, warm air can easily escape which could explain why you’re feeling cool air coming from your furnace instead of heat. If your air filter is dirty, replace it ASAP. A dirty furnace filter is the root cause of many problems. Basically, the furnace isn’t lighting the fuel, meaning it can’t heat your home, either. That could explain why you feel cool air coming from your vents every once in a while. Do this: Try relighting the pilot light following these steps: Step 1: Turn off your furnace An overtaxed furnace will often overheat and malfunction, and end up blowing cold air. Another noise is when you hear the furnace blower running excessively. Terms and Conditions | Privacy Policy | Sitemap Bay Area plumbing, heating and air conditioning contractor. Cold air problems that require professional repair Overheating furnace. Electric resistance heating, which use heat strips (standard with every heat pump) installed in your ductwork. A weak power source won’t trigger the sail switch, and it won’t regulate the air flow. Otherwise your electric heater or gas furnace will not turn on. After making sure your thermostat is set to HEAT, make sure the fan is set to AUTO and not ON. Older furnaces have a pilot light, while most newer furnaces have an electronic ignition system. 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