Common Furnace Issues When You First Turn It On

It’s officially fall, and although temperatures have been unseasonably warm, sooner or later, you’ll be turning on your furnace for the first time in a while. Before you run your system for the first time, there are a few things you should do. But even if you do everything you’re supposed to, you may find that your furnace is having issues right from the get-go.

Let’s go over some common furnace issues that can pop up when you use your furnace for the first time. Some are normal, while others may signal the need for furnace repair in Milford, CT. Here’s what you need to know.

What to Do Before Turning Your Furnace On

Here’s a quick checklist of tasks to complete before switching on your gas or electric furnace.

• Check the filter and replace it if it’s dirty
• Check that the thermostat is working properly and is in “heat” mode
• Test smoke and carbon monoxide detectors and their batteries
• Clear the area around the furnace so there’s a 3-foot area of open space surrounding it
• Schedule annual furnace maintenance if you haven’t done so already

Common Furnace Problems When You Turn Your Heating On

Some things are expected when you turn your furnace on for the first time in the fall, but some are not normal and are cause for concern. Let’s go over potential issues.

Burning Dust Smell

The smell of burning dust or dirt is perfectly normal when you turn the furnace on for the first time. During months of non-use, dust accumulates on the furnace’s components and inside the ducts. If you have a gas furnace, when the furnace ignites, and when the system heats up for the first time, the dust burns off, creating that distinct odor. This odor should dissipate soon and is only a problem if the smell continues.

Ignition Problems

Furnaces can also experience ignition issues, especially older models with pilot lights. A pilot light that won’t stay lit or struggles to ignite is a common problem when first starting the furnace. Furnaces with electronic ignition systems can experience sensor or switch malfunctions, preventing them from turning on after a period of non-use. Give us a call if your furnace doesn’t seem to be switching on.

Thermostat Issues

Is your furnace not emitting any heat? Some homeowners have difficulty switching their HVAC system from cooling to heating mode. It’s often the case that the thermostat is in “cooling” mode when it needs to be switched to “heating” mode. If you haven’t used the thermostat since the last heating season, the batteries may need to be replaced. 

Strange Noises and Unusual Smells

If you hear unusual noises such as banging, rattling, or squealing when you start the furnace, these issues should be addressed quickly to avoid further damage. Other than that burning dust smell we mentioned, your furnace should not emit any other unusual smells. If you detect the odor of natural gas, turn the furnace off immediately.

Frequently Asked Questions

Question: Why does my furnace smell like burning when I first turn it on?
Answer: A brief burning dust smell is usually normal when you first start your furnace after months of inactivity. Dust can collect on furnace components and inside ductwork, then burn off as the system heats up. The odor should fade fairly quickly. If it continues, the furnace should be inspected.

Question: Why won’t my furnace turn on after sitting unused for months?
Answer: A furnace may fail to start because of an ignition problem, thermostat issue, or malfunctioning sensor or switch. Older furnaces can also have pilot light problems. Before calling for repair, check that the thermostat is working, has fresh batteries if needed, and is set to heating mode.

Question: Why is my furnace running but not producing heat?
Answer: If the furnace is running without producing heat, start by checking the thermostat. It may still be set to cooling mode instead of heating, especially when switching seasons. Weak thermostat batteries can also cause problems. If the settings are correct and there is still no heat, professional diagnosis may be needed.

Question: Are strange furnace noises normal when turning it on for the first time?
Answer: Banging, rattling, squealing, and other unusual furnace noises should not be ignored. These sounds can indicate mechanical problems that may worsen if left unaddressed. A furnace should generally operate without loud or unusual noises, so scheduling an inspection can help identify the source before additional damage occurs.

Question: What should I check before turning on my furnace for the season?
Answer: Before starting your furnace, check the air filter and replace it if dirty, confirm the thermostat is working and set to heat, test smoke and carbon monoxide detectors, and clear items away from the furnace. It is also a good time to schedule annual furnace maintenance if it has not been completed.

Heating and Cooling Experts Since 1959. Contact M&R Mechanical Services today for exceptional furnace repairs in Milford, CT.