A gas furnace will always be one of the best options for heating a home in Massachusetts. That’s primarily because a gas furnace puts out much more heat than the other options, allowing you to heat your house quickly and ensure it stays warm on even the coldest winter days. The only thing is that gas furnaces are so complex and have so many different components that various problems can arise. The good news is if your furnace isn’t working as it should, you can sometimes get it working correctly again just by taking a few steps to try and troubleshoot the problem.
Furnace Isn’t Turning On
This issue may make you think the worst and fear your furnace is dead and must be replaced, but luckily, this is rarely the case. Instead, there’s likely a more minor issue keeping your furnace from turning on. The two things to check first when facing this situation are that the batteries in your thermostat aren’t dead and that the circuit breaker for your HVAC system isn’t tripped.
Some thermostat batteries serve as a backup that ensures the thermostat doesn’t get reset whenever the power goes out. Others rely directly on battery power to stay on and to signal the HVAC system to turn on and off. While you’ll usually see a notification on the thermostat screen that tells you when the batteries are low, this isn’t always the case. As such, you may want to try replacing the batteries to see if this fixes the issue. Another thing you can try to do is adjust the thermostat settings since this can help you determine if the issue is related to your furnace or the thermostat itself. Even though the blower or fan works alongside your furnace, the two are still separate components. If your thermostat works properly, the blower should come on immediately if you switch the fan setting to “On.” If the blower also won’t come on, it usually means an issue with the furnace control board or the thermostat.
Your furnace also won’t turn on if the circuit breaker that controls its power is tripped since various components, like the inducer fan and the electronic igniter, require electricity to work. While it’s fairly rare for your heating system to trip the breaker, it can happen as a result of a power surge or an electrical issue like a damaged wire. If you see that the breaker is tripped, you should switch the thermostat off before resetting the breaker. Once you reset the breaker and turn your thermostat back to heating mode, your furnace should turn on fairly soon. As long as it runs as it should from then on, you typically don’t need to worry. The issue is if the breaker trips again since this likely indicates that your heating system has an electrical fault that needs to be repaired by a furnace professional.
If you’ve checked the thermostat and the breaker and your furnace still isn’t turning on, the only option is to have a professional perform an inspection. In this case, you could be dealing with a bad gas valve, broken pressure switch, worn-out electronic igniter, or a variety of other issues.
Furnace Keeps Shutting Off Before It Should
Your furnace should run for however long until the thermostat shows that your house is at the right temperature. If it keeps shutting off before your house reaches the right temperature, turn your heating off and then check the air filter. If the filter looks fairly dirty and is starting to turn black, this is likely the source of the problem. An overly dirty filter will commonly cause a furnace to overheat because it’s not receiving sufficient airflow, and the temperature-limit switch will always force a shutdown when the furnace gets too hot.
If the filter isn’t dirty or the issue continues after putting in a new filter, it often indicates that the flame sensor isn’t working as it should. A flame sensor that’s overly dirty or beginning to wear out can often have issues where it doesn’t always sense that the burners are lit. When this happens, the gas valve in the furnace will almost immediately close so that the burners go out. This is a safety precaution since the purpose of the flame sensor is to ensure you never have gas flowing to the burners when the furnace isn’t on. You’ll need a professional to inspect the system if changing the filter doesn’t help.
There can also be times when a thermostat suddenly stops working for a short time, resulting in the furnace immediately going out. This can happen if the batteries are low, the thermostat is starting to wear out, or there’s an issue with the wiring that connects the thermostat to the furnace’s control board.
Furnace Isn’t Producing Sufficient Heat
Another fairly common issue is that a furnace suddenly stops heating effectively for one reason or another. You’ll notice this fairly quickly since it results in the furnace staying on longer than usual. Most thermostats are programmed so that there is only a 1-2 degree setback, which means the furnace should run as soon as the temperature drops 1-2 degrees below your normal temperature setting. The furnace then shuts off when the thermostat registers the temperature is half a degree above the temperature setting.
If your furnace starts running for an unusually long time, you should again check that the air filter doesn’t need to be changed. The filter may be dirty enough to limit the amount of air that enters the furnace, reducing the amount of hot air that is put out.
When dealing with this issue, the other thing is to look inside your furnace when it’s running to see what color the flames are. The flames should always be steady and bright blue. If you see that the flames are orange or yellow and flickering, the gas isn’t burning cleanly, and the flames are giving off far less heat. This can happen because the flames aren’t getting enough oxygen or the burners are dirty. In either case, this is something you want to have a professional check out immediately since yellow or orange flames also often indicate that carbon monoxide is being produced, which is obviously a major health and safety issue.
If the filter is clean and the furnace produces bright blue flames, it usually means the furnace has some other airflow issue. This could be a problem with your ductwork or a malfunctioning blower. Another possibility is that you simply have too many vents closed; closed vents can also make it far more difficult for an HVAC system to move air around the house, leading to the system heating more slowly.
DeWolfe Plumbing, Heating & Cooling is a family-owned company with over 90 years of experience helping Massachusetts home and business owners with their heating and air conditioning needs. We offer expert furnace repair and all heating maintenance services, and can quickly diagnose whatever issues your furnace or AC has. You can also trust us if you need any HVAC installation or plumbing services in the West Boylston or Falmouth areas. To schedule an inspection and diagnostic assessment and get help overcoming your furnace issues, contact us today.
