A home heating system that blows cold air instead of warm can be an extremely frustrating problem. Many homeowners don't know how to deal with this situation, but there are actually a few troubleshooting steps you can take which may help to diagnose or even solve the problem. Here are four things to check before you call a heating or HVAC contractor.

1. Is the Thermostat Set Correctly?

Before you call for help, it makes sense to check for obvious solutions to the problem of your home heating system blowing cold air. If the fan is turned on but the furnace is not currently heating, the system will blow cold air into your home. Check the thermostat and timer settings before you assume your home heating system is broken.

2. Has the Pilot Light Gone Out on the Furnace?

If the controls are set correctly, but your furnace is not heating the air that blows around your property, it could be that the furnace pilot light has gone out. If this happens, the furnace will not be able to heat the air.

Sometimes, this problem is easy to fix. You simply need to relight the pilot light. If you are not able to light it, it could be that the gas supply is blocked. Try cleaning the pilot light to remove any dust or grease that might be blocking the supply. If this doesn't solve the problem, you will need professional help to clear the blockage and fix the gas supply to your furnace.

3. Does the Air Filter Need Changing?

If your furnace is working properly but your heating system is still blowing cold air, you may need to clean or replace the air filters. When these filters become blocked, air does not flow correctly through the heating system. In most home heating systems, the air filters are easy to access and replace, but you can also contact a home heating professional for help if you do not know how to carry out this job.

4. Are the Heating Ducts Leaking?

If the ducts that are responsible for delivering warm air to the various parts of your home are leaking, hot air can mix with cold and create the impression that your heating system is not working correctly. Check ducts in the attic and crawlspace for leaks. You may be able to repair these leaks with tape, or you can replace damaged sections. If you cannot find a leak, contact a home heating service for help.