Few things are more frustrating than huddling in a chilly house while the furnace blasts. You might be wondering, “Why is my house cold when I can hear the furnace running?” This is a common home heating problem with several potential solutions. Follow these step-by-step troubleshooting tips to get to the bottom of it.
Check the Thermostat
Your thermostat controls when and how your furnace runs, so it’s a great place to start:
- Double-check that it’s set to “heat” instead of “fan” or “cool.”
- Confirm that the temperature you’ve selected is higher than the current room temperature.
- If your thermostat uses batteries, install fresh ones to rule out power issues.
- For smart thermostats, verify the Wi-Fi connection and app settings to make sure your commands are reaching the system.
Open All Air Vents and Registers
Even when your furnace is doing its job, the heat still has to reach your living space. Walk around the house and make sure every vent and register is open. Rugs, curtains, and furniture can restrict airflow without you realizing it, so make sure none are causing obstructions.
Replace or Clean the Air Filter
When was the last time you replaced the filter? If it’s been more than three months, this could be the reason your house is cold even when the heat is on. After all, a dirty filter restricts airflow, making your furnace work harder to push warm air through. This leads to uneven heating, higher energy bills, and unnecessary wear and tear.
During this furnace troubleshooting step, pull out the filter and take a closer look. If it appears clogged, it’s time to replace it. When inserting a new filter, make sure the arrow points in the direction the air flows. If you feel unsure, ask your HVAC technician to demonstrate how to replace the filter during your next scheduled maintenance visit.
Pin Down Drafts and Heat Loss
Sometimes the problem isn’t the furnace at all. If your home is leaky, no amount of heating will keep it warm. Here’s how to address air leaks and poor insulation:
- Walk around and feel for drafts near windows and doors. Seal any you find with caulk, weatherstripping, or draft stoppers.
- Check for cold air around outlets, switch plates, and areas where pipes or wiring enter the house. Improve efficiency with gaskets and spray foam.
- Check the attic and exposed rim joists in the basement. Adding insulation to these areas helps lock in heat and makes your home feel more comfortable.
Inspect the Ductwork
If your furnace is the heart of your heating system, the ducts are the arteries and veins. Leaks or gaps along the way may let heat escape into unconditioned areas like the attic or crawl space, leaving your home colder than it should be.
Inspect visible ductwork for loose connections or crushed sections. Dust streaks along seams are often signs of air leaks. You can seal small gaps with duct mastic or foil tape, but leave larger issues to a professional.
Check Your Furnace
Now, it’s time to look at the furnace itself:
- Listen closely when the system runs. Banging, rattling, or squealing noises may point to mechanical issues.
- If you have a gas furnace, inspect the pilot light. A steady blue flame indicates normal operation, while a yellow or flickering flame signals trouble.
- Check the electrical panel to see if the furnace breaker has tripped.
If these checks don’t solve the issue, call a licensed HVAC technician to take it from there.
Trust Tom Drexler for Home Heating Solutions
When basic furnace troubleshooting doesn’t resolve the problem, you need a heating team you can count on. Tom Drexler Plumbing, Air & Electric has served Cincinnati, Louisville, and Southern Indiana homes since 1982. We offer upfront pricing, free replacement estimates, and a 100% satisfaction guarantee. Our licensed and insured technicians are background-checked, highly trained, and committed to fixing your fickle furnace the first time around.
Contact us today to schedule home heating solutions designed to restore comfort and efficiency.
