The only time your furnace should be blowing out lukewarm air is when you set the thermostat to do so. If it continues to give out anything less than hot air in spite of the correct settings, something is wrong. More often than not, the reasons behind a sudden change in temperature are minor issues that can be solved with the help of a reliable HVAC technician. However, as a homeowner, it pays to have a better understanding of your furnace so that you can act accordingly when something goes wrong. So if you’re trying to figure out why your heating system is giving you lukewarm air, here are three of the most likely reasons:
1. Problems with the Thermostat
Your furnace may be in tiptop condition yet underperforming, simply because your thermostat isn’t working. When you call for a HVAC repair service, the technician will check the functioning of the thermostat before anything else as this is a very common problem with heating systems. If you haven’t replaced the batteries of your thermostat in a long time, it’s advisable to put fresh ones in and check if there is any difference in the temperature. Though you will generally see the numbers fading on the display when the batteries are dying, sometimes there is no such indication and hence, the thought doesn’t cross your mind.
The settings of the thermostat can also be the reason why lukewarm air is coming out of your furnace. For example, some settings leave the blower fan on while the heater shuts off. This, in turn, sends out lukewarm air as the system starts to cool down.
2. Clogged Air Filters or Installation Problems
Depending on what type of furnace you have, your air filters will have to be cleaned and replaced every now and then. Clogged filters not only contribute to indoor air pollution, but can also hinder the performance of your furnace. The clogging obstructs airflow, trapping some of the hot air inside. This is evident when the temperature in the room suddenly drops and you start to feel lukewarm (instead of hot) air coming out.
Another issue wherein the air filters are causing the furnace to blow out lukewarm is when they haven’t been installed properly. In some cases, they may accidentally be put in backwards after a cleaning and hence, end up blocking the hot air intended to blow out.
3. Breaks in the Ductwork
Another common reason for your furnace to suddenly drop air temperature is due to breaks in the ductwork. If the hot air traveling through the ductwork and out of your vent is getting leaked, the air pressure naturally drops and gives out lukewarm air instead. Even the smallest of breaks can cause the temperature in a room to drop; hence, you need to call in a professional HVAC repair service, to check for any breaks and seal them as soon as possible.