Why Is My Heating System Blowing Cold Air?

Is your unit struggling to heat your home?

While we’ve had some seasonally warm temperatures lately in the Lowcountry, that winter chill still sets in at night. Have you turned on your unit recently only to get a big blast of cold air? This can happen occasionally and isn’t necessarily a sign of a bigger problem. But it still could be a problem.

Have you given your unit time to properly warm-up? If you just adjusted the temperature or if you’ve just turned on the heat altogether, it may just be as simple as your heater needing some time to warm up. Allow your system to run for about 5 minutes and see if the air starts to heat up. Hopefully, all it needed was a little patience. If it doesn’t blow warm air after 10 minutes, there may be a larger issue.

Is someone else in the house adjusting the temperature? Check and make sure that no one has turned down the unit. People have different preferences on hot vs cold and someone may be making a change that you’re unaware of. 

If that doesn’t do the trick, the next thing to check is your thermostat unit itself. If it’s set to “on” instead of “auto”, the system will run continuously, even if it isn’t on the heat cycle, meaning cool air will blow throughout. If your thermostat runs on batteries, check those to make sure that they are fully charged. If you have a programmable thermostat, check to make sure that nothing looks off on the settings.

What about those filters? Did you know that a dirty air filter can cause big problems? When airflow is restricted from the evaporator coil, the refrigerant will not turn into gas and instead of releasing heat, the coil will release cool air.

Next, check the heat pump, if you have one. Make sure that there isn’t any debris clogging the unit. Other things to check include low refrigerant, bad valves or a faulty metering device. If the refrigerant has leaked, no heat can be absorbed because the refrigerant helps with the transfer of heat between your indoor and outdoor air. These are all things the Blanton’s Team can help you with! 

A stuck reverse valve could also be causing some issues. Reverse valves switch between the cooling and heating modes to help the heat pump work as both an air conditioner and a heater. Your reverse valve could malfunction with age or get stuck in one of the modes. If it’s stuck in heat mode, it will only blow cool air. Try putting your unit on both modes at once and see if warm air is blowing inside and cool air outside at your unit. Now try the opposite. If it keeps blowing cool air inside your house, chances are the valve is defective.

If your furnace is electric, a tripped breaker may be causing the problem and heat cannot circulate throughout your house. In fact, it may not even run at all so check to see if you have a tripped breaker. If you have a gas furnace, the electric starter ignites the gas burner. So if your breaker is tripped, the furnace could stay on forever but the air won’t warm up because the gas won’t ignite.

Lastly, let’s check that the compressor capacitor is not defective. Newer air conditioners come with dual capacitors that power both sides, the compressor and the fan motor. If the compressor dies, the fan motor will still continue working and will be blowing air when you run your air conditioner. Because the compressor isn’t working, the refrigerant cannot circulate around the coil and heat will not be transferred into your home.

Blanton and Sons is here to help you keep your home warm or cool when you want it! And remember to ask us about our Preventative Maintenance Plan.