Furnace Repair: 8 Common Problems and How to Solve Them
Common Furnace Repair ProblemsDuring the winter months, having your furnace quit working is a bad situation. In this article, we look at the most common furnace problems, and how to troubleshoot them.
The Two Main Types of Gas FurnacesDuring the fall and winter in San Jose, Morgan Hill, and the South Bay, hundreds of people will experience a problem with their furnace or heating system. Whether your furnace is a residential or commercial unit, the same basic issues are common when the heat goes out. Gas furnaces fall into two types: conventional gas furnaces and high-efficiency gas furnaces. Conventional furnaces are up to 89% AFUE (Annual Fuel Utilization Efficiency). High-efficiency gas furnaces are 90% AFUE and above.
Conventional Gas Furnaces vs. High-Efficiency FurnacesA conventional gas furnace works like this: it takes in takes in cool air, cleans it with an air filter, heats it up with a gas burner using a heat exchanger, then blows the air through the air ducts distributing the heat. The air eventually cools down and comes back to the furnace through return air inlets and ductwork. Conventional gas furnaces either have a standing pilot light or electrical ignition. High-efficiency condensing furnaces differ from conventional furnaces in the way they exchange heat after combustion and distribute heat. The heat extraction process is more efficient than in convention gas furnaces. Now, let’s look at the most common problems people encounter with furnaces.
1. Your thermostat is malfunctioning.If your home is not heating up, it might not be due to the furnace. It may be because the thermostat is faulty. A faulty thermostat can cause the furnace to cycle on and off sporadically, fluctuate the temperature, or not turn on at all. It’s also possible that the thermostat is mismatched to the heating and cooling unit. Not all thermostats are designed the same. Using a mismatched thermostat with your HVAC unit can cause unexpected behavior from your furnace.
2. The air filter is dirty or clogged.When the air filter is clogged or dirty, it cuts off the airflow to the furnace. The furnace must subsequently work harder to distribute the heated air to the home. In certain cases, a dirty air filter can damage the limit switch, which controls the blower, which circulates the air through the ductwork. If your furnace doesn’t seem to working efficiently, check to see if the filter is dirty. The filter will usually be located in the intake or in the furnace housing itself. If the filter is dirty, it may be time to replace it.
Dirty or clogged air filters reduce airflow, making a furnace work harder to circulate. In some cases, a clogged filter may damage the limit switch, which controls the fan.