When it’s cold outside the last thing you want is for your furnace to deliver a continuous chilly blast of cold air instead of warm air. Usually the reason for the cold air is simple and easily corrected.
1. It’s just blowing cool air when you first turn the unit on. Take for instance when you first get into your car and turn on the heat, it initially blows cool air. Generally, it takes a few minutes for the warm air to start blowing to warm the car up. This is normal as long as the air turns warm within a few minutes.
2. Check your thermostat to be sure the fan is set to the “AUTO” position, rather than “on”. Having the fan set to “on” means the fan is running even when the furnace is not producing heat. You want to have the fan shoot out the warm air whenever the furnace goes on.
3. In the case of older furnace systems, the pilot light may have gone out, causing the fan to blow cold air when it comes on. Check the manufacturer’s instructions about re-lighting the furnace safely, or contact a HVAC company. If the pilot light won’t stay lit, there may be a problem with the thermocouple, which should be handled by a professional HVAC technician.
4. When you seem to have warm air at first, but it quickly starts blowing cold, the flame sensor may be overdue for a good cleaning. A dirty flame sensor can cause the gas burner to keep going out, which means you’ll get warm air at first, then no flame, no warmth.
5. What if your furnace starts out blowing warm, then cold air and then stops blowing any air at all? Your furnace may be over heating. In the case where the furnace overheats, the furnace air filter may be dirty, creating a blockage to the airflow, in turn causing your furnace to run longer periods than necessary to heat your home. There’s a built-in safety feature that turns the furnace burners off, but keeps the blower running to cool down the furnace. When the furnace must keep running for longer periods, it will overheat. Try replacing the air filter to see if that solves the problem. If not, schedule a service call to fix the overheating issue and avoid the bigger (more expensive) problem of having to replace the furnace’s heat exchanger.
If you find you’re still having problems, try scheduling a service call to have your system evaluated for energy-efficiency. Better to get ahead of the curve when it comes to proper functioning of your heating system when the winter weather is relentless.
Your service evaluation is only $45, if you call us. If you need additional service or products, we’ll give you a list of options to best suit your household and budget.
75 Degrees is an air conditioning and heating company serving the greater Las Vegas, North Las Vegas, Summerlin and Henderson, NV areas. Energy efficiency and excellent customer care is our primary focus.