Why Your Furnace Fails Below 35 Degrees (And How Furnace Maintenance Can Help)

Normal South Texas winter weather is easy to handle. But when that Arctic vortex sends some crazy cold weather this way, it can be a little disconcerting. Some folks have a perfectly good furnace that just struggles to keep up when the temperature drops very low. If that were your home, there might be a little information that can resolve the issue during the next winter blast.

Types of Residential Furnaces

In this region, there are three types of furnaces installed in Texas homes, with a few exceptions. They include:

• Electric heat is the most common. Metal elements resist the flow of electricity and get red-hot, more than 1,000 degrees Fahrenheit. Air blows across the elements and moves the heat into the home.
• Natural gas heat is also common. A burner assembly burns natural gas or propane inside of a chamber at about 3,500 degrees Fahrenheit. Air is blown around the chamber, heated, and moved into the home.
• Approximately 19% of Texas homes have heat pumps, a high-efficiency newer technology. Heat pumps use the same equipment as the air conditioning system. The air conditioner moves hot air from inside the home to the outside. Heat pumps move hot air from outside the home to the inside.

Heat pumps are ideal in Texas, since we experience relatively mild temperatures. Heat pumps can efficiently collect heat until the temperature drops below 35 degrees. Below that temperature, the heat pump struggles to collect heat. For this reason, heat pumps have an electric heat element as a backup source of heat. Do you have a heat pump? How can you tell if you have a heat pump? Here are a few clues:

• If the outdoor condenser unit runs during heating cycles, you have a heat pump
• If your thermostat has options for heat settings, you probably have a heat pump
• If your furnace struggles to keep the home warm when the temperature drops below 35 degrees, you probably have a heat pump.

If you have a heat pump, you need to be very aware of your thermostat display and settings.

Heat Pump Thermostat Options

Analog thermostats were phased out in the 1980s and 1990s, so chances are you have a thermostat with an electronic display. There are two basic types of electronic thermostats, programmable and Smart varieties. Smart thermostats have an app that connects the thermostat to mobile devices such as cell phones and tablets. Heat pump thermostats will have 2 or 3 heat settings: Heat, EM Heat (Emergency Heat), and AUX Heat (Auxiliary Heat). Each setting serves a different function:

Heat is the normal heat pump setting on both programmable and Smart thermostat varieties. The heat pump is drawing heat from outside and moving it inside. Heat pump heat is a little slower than electric and natural gas heat, but it is very efficient, since the heat pump does not create heat energy; it collects it. You should take note of sudden temperature changes and adjust the thermostat setting accordingly.

Emergency Heat engages the electric heating element as a backup to the heat pump. The heat pump shuts off, and the electric furnace kicks in. It is very important for you to know your thermostat type and capabilities. With programmable thermostats, the setting will need to be changed manually. A Smart thermostat MAY adjust the heating source automatically when the internet weather service indicates the temperature has dropped below the efficiency level for the heat pump. Read your Smart thermostat owner’s manual or find the information online concerning your particular brand and model of Smart thermostat.

Your heat pump thermostat may also have an Auxiliary Heat setting. This is similar to, but different from, Emergency Heat. Auxiliary Heat engages when:

• The temperature drops below 35 degrees for Smart thermostats
• You bump the temperature setting up more than three degrees
• When the heat pump condenser unit is ice or snow-covered, it needs to defrost.

Understanding thermostat functions for heat pumps is essential for staying comfortable, especially when the temperature plummets well below normal winter temperatures.

Schedule Your Furnace Maintenance Today

Don’t wait for the next Arctic blast to find out if your heating system is up to the challenge. Professional furnace maintenance ensures that your heat pump, gas, or electric system is prepared to handle freezing temperatures safely and efficiently. Our expert technicians will inspect your components and thermostat settings to keep your home warm when the outdoor air plummets. Call Northwind Air Conditioning and Heating now to schedule your furnace maintenance appointment and enjoy peace of mind all winter long.