When your furnace stops working or begins to malfunction, your first instinct is probably to call an HVAC technician to examine your system. That’s a good habit to develop, but before you call for professional help there are a few things you should check first. It is possible that your furnace malfunction is actually very minor, and something you can fix yourself. Even though you will likely need to call a professional anyway, examining certain parts of your system beforehand can help isolate and identify the problem. Let’s take a look at what you should check before calling for furnace repair.
The core of any central heating system is the thermostat. It is the brain of your furnace system, which will not act without an order from the thermostat. As such, a malfunctioning thermostat can pretty effectively cripple your entire furnace. If your furnace stops working, you should always check your thermostat before doing anything else. Examine the display on the thermostat and make sure that all the information and settings are correct. An incorrect display is a sign that something is wrong with your thermostat.
The Air Filter
The air filter is responsible for protecting your furnace from dust and debris that blows in from the ducts. Though it does this job well, the filter has no way to rid itself of any particles that it collects. If not cleaned or changed out every 1-3 months, the air filter can become clogged. This restricts the air flow through the system, trapping heat inside the furnace and causing it to overheat. When this happens, it trips a device called the “limit switch,” which shuts the furnace down as a safety measure. If your furnace suddenly shuts down and won’t restart, it is possible that it overheated due to a dirty air filter. If you replace your dirty air filter, that might be all that is needed to solve the problem.