With winter temperatures falling as low as 10 degrees Fahrenheit, natural gas heating is an excellent choice for your Nashua, NH home. Gas furnaces burn hotter than other heater types. When working like they should, they emit steady, even streams of heat. Not only do they burn hot enough to beat back the local chill, but they also heat homes more quickly than other heat types. Thus, if your gas furnace is running non-stop, you have a problem. Read on to discover the most common causes of non-stop gas furnace operation.
Start by Checking Your HVAC Air Filter
Dirty air filters lie at the heart of countless HVAC problems. Whether your furnace is short-cycling, overheating, or running non-stop, this is the first component to check. Although HVAC air filters provide modest indoor air quality (IAQ) benefits, they primarily exist to protect heating equipment.
Air filters sieve out large-sized, airborne particulates like carpet fibers, pet hairs, human hair, dust, and lint. This keeps them from settling on your furnace’s thermocouple, heat sensor or intake valve. When collected debris breaks free from dirty filters, it can land on these components and cause your furnace to overheat.
Overheating furnaces automatically enter “cool down” mode. Although furnaces aren’t producing heat while cooling down, the fan will continue to run.
Overheating and Dirty Filters
Fuel-combusting furnaces have multiple failsafe measures to limit the risk of overheating and furnace fires. Build-ups of dry, dusty debris at the interior of fuel-combusting appliances are never a good thing. Thus, although you may be able to solve your problem by taking your old filter out and putting a new one in, it’s also a good idea to schedule mid-season furnace maintenance. This will give our techs the chance to clean both the interior and exterior of your heating equipment so that the issue doesn’t quickly recur.
How to Avoid Filter-Related Performance Issues
Whether new or old, all gas-fired furnaces require professional maintenance every year. It’s best to schedule this maintenance in late fall or early winter, before first turning your heater on for the cold season. If your furnace emitted a dry, burnt, dusty smell when you first used it this winter, you probably skipped this appointment.
Having furnaces cleaned and maintained extends the lifespans of their air filters and allows for cleaner, healthier indoor air. You should also inspect your furnace filter once each month and change it every 30 to 90 days as needed.
Check Your Thermostat Setting
The next likely culprit is your thermostat. Several thermostat issues can cause furnaces to run non-stop. You might have an old, failing thermostat that’s no longer sending the correct signals, or your thermostat may be set incorrectly. If your thermostat is set to “AUTO”, your furnace’s fan will automatically kick into action during heating cycles. If your thermostat is set to “ON”, your furnace fan will run continuously. Much like dirty filters, this can also result in cool or lukewarm air coming from your vents.
Consider Upgrading to a Smart Thermostat
You may have someone in your household who found the indoor temperature too low for their tastes. It’s not uncommon to have multiple people adjusting the thermostat in large and busy households. You might find that your thermostat is set at its highest setting. Many consumers are under the mistaken impression that high thermostat settings expedite heating.
Upgrading to a smart thermostat is an easy way to monitor and adjust your thermostat setting, even while you’re away. These Wi-Fi-enabled devices are paired with branded apps. You can download your smart thermostat’s app to your mobile phone and use it to raise or lower your thermostat’s temperature setting, track temperature changes and HVAC use, get alerts on your HVAC system’s health and performance, and more.
Your Thermostat’s Location Matters
Your thermostat tells your furnace what to do. Apart from emergency shut-offs, furnaces won’t turn off or on until they’ve received signals from these devices. Not only do you need a working thermostat, but you also need this device in the right location. A thermostat that’s too close to an oven, heat lamp, gaming computer, or other heat-generating appliance will rarely read your indoor temperature correctly.
Conversely, if your thermostat is right near a drafty basement or garage door or in a remote room that doesn’t get adequate heat from your HVAC system, it will likely register your indoor temperature as being colder than it is. This can cause heaters to run longer heating cycles or run non-stop. A two-story house will typically have a second floor that is warmer. A downstairs thermostat can also make your furnace run longer than needed if your main living space is upstairs.
Look for HVAC Air Duct Leaks
There’s always the possibility that your furnace is working correctly but your HVAC ductwork is failing or underperforming. You can check exposed ductwork in areas like your attached garage for structural damage, but you should schedule a professional ductwork inspection every few years. When HVAC air ducts are leaky, some of the heated air that gas furnaces produce is released into unheated crawlspaces or in attic and basement areas. Despite burning lots of fuel and running continuously, heaters that lack functional ducting can’t reliably create the temperatures that are set at their thermostats.
It’s also important to have your ductwork sealed and insulated. According to the University of Florida, HVAC air ducts can be responsible for the loss of up to 40% of a furnace’s heat energy. These losses increase when ductwork is unsealed. With heated air losing much of its warmth before distribution, your furnace must work both longer and harder to get its job done.
Seal up Air Leaks in Building Materials
In addition to leaky ducts, you might want to check for air leaks in building materials. If you haven’t done so already, consider beefing up your home’s insulation, adding weatherstripping to your windows and doors, and caulking any visible cracks and gaps in your walls.
Your Furnace’s Gas Pressure Doesn’t Match Your Elevation
During furnace installation, furnaces are often derated. Derating balances a furnace’s gas pressure to match the elevation. At its highest point, Nashua is just 426 feet above sea level. If your furnace filter is clean, your home is well-sealed, and your ductwork is intact, scheduling furnace service will tell you whether derating is needed.
Your Furnace Is the Wrong Size for Your Home
Most HVAC companies use a highly complex calculation known as the Manual J Load Calculation to determine the heating and cooling needs of individual buildings. This is the only way to accurately size heaters and air conditioners and it helps homeowners avoid long-term problems with overheating, short cycling, icing, and nonstop operation.
If the Manual J wasn’t used when sizing and installing your furnace or if it was performed incorrectly, you may have a furnace that is too big or small. Another possibility is that changes in the layout of your home have altered your heating needs. For instance, if you recently added a new bedroom, created an open layout, or replaced major building features such as siding or roof, your furnace could be too small to meet your heating demands.
How Long Is a Natural Gas Heating Cycle?
Many natural gas furnaces run heating cycles that last just 10 to 15 minutes. With five to 10-minute breaks between these cycles, your furnace should run two to three cycles per hour. You can test the rate that your furnace uses by increasing your thermostat by ten degrees or so and then timing how long it takes to get to that temperature. If your furnace runs for significantly longer than this rate or stops producing warm air, turn your heater off, check its air filter, and perform other basic, troubleshooting measures. For fast accurate diagnoses and solutions, it’s always best to contact a professional.
Homeowners in Nashua, NH and the surrounding cities can count on us for expert heating repair, cooling, and indoor air quality services. We also provide smart thermostats, oil-to-gas conversions, and water heaters. If your furnace is overheating, short-cycling, or running non-stop, give Joyce Cooling & Heating Inc. a call.
