It can be very disconcerting when your furnace appears to be running fine, but then you notice that your system is not blowing warm air. This obviously will compromise the comfort level of your home, but it is also indicative of an underlying problem. There are a number of reasons why this issue can develop, so here we will explore whether you should be alarmed and if you need an emergency repair.
Check Your Thermostat Settings:
The first port of call to diagnose a potential problem is to check your thermostat settings. If the fan is running, but the furnace is blowing cold air, it could be due to incorrect settings. When the fan has been set to on, the furnace blower will constantly be operating, yet there will no heat produced. Any cool air you can feel coming from the vents are likely to be just from the fan blowing.
This issue has a very easy fix, as all you need to do is change the fan settings from On to Auto. This will tell your furnace to blow warm air when the furnace is running.
Your Furnace has Overheated:
An overheating furnace may be the reason why your vents are emitting cold air. Often a furnace overheats simply because the air filters have become dirty. A clogged air filter will restrict airflow, which causes the furnace to run for longer in order to heat your home.
Bear in mind that if your furnace is constantly overheating, it can cause damage to the heat exchanger. If the issue reaches the heat exchanger, you are likely to need a replacement. Therefore, you need to address the issue before it reaches this potentially costly stage.
Your Pilot Light has Gone Out:
Another reason why your heating system may not be emitting warm air is because the pilot light has gone out. The instructions for relighting a pilot light are usually found on the furnace unit or in the owner’s manual. This can be an issue if you have no experience with this type of equipment, so you may require professional assistance.
Other Underlying Causes:
If you have confirmed that your heating system has not been compromised by these issues, there are a few other reasons why you are not getting warmed air. This can include a dirty flame sensor, which could prevent the burner from staying lit, or a restricted gas supply. Additionally, the condensation drain lines may be clogged, or there could be damage to your ducts.
If you have investigated all of these issues and you have still not resolved the problem, it is likely that you will need to consult a professional HVAC specialist. It may be the case that your furnace is not the correct size for your property or requirements. An experienced HVAC technician will be able to perform a thorough check on your system to determine the underlying problem. Cold air blowing from your heating system is a significant problem, and the cause can vary, so it is important that you don’t ignore the problem and have it checked as soon as possible.