It's Cold in Here! Trivia Quiz

Answer: Ask yourself, "When did I last change the furnace filter?"

A high percentage of furnace failures are related to a furnace overheating due to poor air flow, and the number one reason for poor air flow is a dirty furnace filter. If it's been a couple months, or more, since the filter has been changed, then the odds are high that is the problem. So the first thing heating professionals recommend to a homeowner when their furnace stops heating, even before recommending a service call, is to try to determine if a dirty filter is to blame, and if so, change the filter.

As an aside, it is unsafe to turn on an oven with the door open. This can cause carbon monoxide build up in your home.

Answer: Check if the thermostat needs new batteries

Though it's less likely to be the cause of a surprise furnace failure, because most thermostats have low battery indicators, a dead battery in a thermostat is something that a homeowner can take care of themselves to avoid a service call. Buying a new furnace, or investing in a heat pump conversion can become options for people whose furnaces have failed completely or people that want a more eco-friendly option, but in a pinch, when it's cold in your home, check the batteries.

Answer: On the front of a furnace, behind a plastic window

Most modern furnaces have indicator lights that can tell an observer a lot, whether that's a technician or a homeowner. Typically an indicator light can be seen from outside the furnace through a window, or possibly a slit, in the access panel on the front of the furnace.

The light or lights indicate whether the furnace has sensed a problem or not, or if the furnace is receiving power or not. It is a good idea for a homeowner to record the number of blinks they see, or if it is a steady light, and what color or colors the lights are.

Answer: Manually resetting the furnace

A dirty filter is a very common problem which makes the odds significant that the furnace has overheated, perhaps multiple times, causing the furnace to go into a "high limit lockout." The remedy for this is a manual reset. To do this, first turn the system off at the thermostat, then disrupt power to the furnace and then restore it. Some furnaces are hard wired with a switch, in which case, flip the switch off and then back on. Other furnaces are plugged into the wall into a normal outlet, with those you just unplug the furnace and then plug it back in.

Sometimes in the case of a difficult to access furnace, for example if it's located in an attic or crawlspace, you can disrupt power at the breaker panel by flipping the breaker off and then back on. In the case of a furnace like this, the homeowner would have been unlikely to have observed or recorded any status codes, and they may actually find a tripped breaker. After restoring power to the furnace, turn the system back on at the thermostat and set it to call for heat. Never spray a furnace with water.

Answer: Check the error code key on the inside panel of the furnace (after shutting it off)

Research into what the blinking status codes are saying can be helpful. A homeowner should always unplug or flip off the power switch to the furnace before removing the panel if they want to check the key located there, and it is important to note that if a homeowner removes the access panel on their furnace, even if there is no power to it, that care should be taken to avoid touching the components on the inside. Even with the furnace off or unplugged, jostling the wiring or components can cause problems.

Answer: The safety mechanism that ensures the induced draft motor is expelling vent gas is open

An open pressure switch could be because the induced draft motor is not working correctly, or the switch is clogged, or the tube that connects the inducer motor to the switch is clogged. Ensuring that the inducer motor is working correctly is very important. If that motor fails there is nothing to prevent the furnace from emitting dangerous carbon monoxide into the living space.

Answer: Flame Sensor

A flame sensor is a term commonly used to describe the safety sensor that tells a furnace that it is actually lit and not just emitting gas into the furnace cabinet. Another word for a flame sensor is a thermocouple. A thermocouple is a temperature sensor composed of two dissimilar metal wires joined at one end, while a thermopile is a device that uses multiple thermocouples connected in series.

Answer: Call a reputable, licensed, heating engineer for service

A furnace repair should always be performed by a licensed, experienced HVAC technician. Remember that a furnace is a gas appliance and can be dangerous if it is mishandled. Only basic maintenance, like filter replacement and replacement of the batteries in the thermostat, should be performed by a homeowner.

Answer: Heating, Ventilation, Air Conditioning

Most of my family, including myself, are HVAC professionals. We work to ensure that your "heating, ventilation and air conditioning" are working correctly. There is also a variation on HVAC that includes an R for Refrigeration and appears like this: HVAC/R. Professionals trained in the refrigeration portion of HVAC/R are responsible for the maintenance of larger commercial walk-in style freezers and refrigerators, on top of comfort cooling.

Answer: Every three months

Equipment manufacturers will vary on this, and some people may find that they have to change it out more frequently, due to pet hair for example, but all manufacturers recommend more frequently than once a year.