Manufacturer Rebates & Tax Incentives Are Available Now - Call Us for Details! Read More

Skip navigation

Call J&A today, Sleep-tight tonight!


Johansen & Anderson Inc Blog

Why is My Heat Running but Not Heating?


It’s a confusing and frustrating feeling when you hear your heating system running, but your house doesn’t warm up! What could possibly cause that?

And how do you get your house warm? Especially as winter really starts to set in, you don’t want to dawdle while your home gets chillier and chillier. We’ll discuss some of the problems that might cause your heat to run without heating your house up, and some quick solutions that might resolve the problem.

Clogged Air Filters

When an air filter is packed with dust and debris, it can make it hard for any air to flow through, stopping up that warm blast that you’re accustomed to feeling from your heat vents. Worse, a clogged air filter can cause the furnace itself to overheat. This will trip the safety controls and prevent the furnace from continuing to heat up. Either way, cleaning or replacing the air filter is a good first step to see if you can resolve your problem yourself.

Thermostat Troubles

Sometimes, the problem isn’t the furnace at all. Perhaps someone accidentally bumped a switch on the thermostat and set the HVAC system to cool instead of heat. Perhaps there’s a fan switch set to “on” instead of “auto” so that when the heat isn’t on, cold air keeps blowing out of the vents. Maybe there’s dust inside the thermostat panel causing trouble—you can open the panel and blow gently to dislodge it. Maybe the batteries are dying, which can send wonky signals to the furnace. Try replacing them. Maybe the thermostat is correctly reading a high temperature because there’s another source of heat too close to it, like a space heater or cooking appliance.

Duct Issues

Is there any chance that the ductwork leading to the cold vent has been closed? When they’re open, the dampers (that’s the term for the handles on the front panel) will be parallel to the duct itself. If the dampers are perpendicular, the duct is closed. Other duct issues include damage and leaks, so if you see anything along those lines, duct repair might be necessary.

A Closed Gas Supply Valve

If you have a gas furnace, and you think there’s any chance someone might have shut off the gas, you can easily check this yourself. Gas supply valves are sometimes closed while repairs are done. If the gas valve handle is perpendicular to the pipe, it’s off. If it’s parallel to the pipe, it’s on.

Pilot Problems

In older gas furnaces, there is an actual pilot light that makes a continuous flame. If this is out, it’s a good idea to call your gas company. The pilot may have gone out because the gas was turned off for maintenance or because of an emergency, and your gas company can confirm the cause and let you know if the gas is safely back on now so you can relight the pilot. If your pilot just won’t stay lit, it’s time for a technician to assess the situation. It may be that there’s something wrong with the ignition system or the thermocouple. 

Other pilot problems, such as with the electronic ignitor or flame sensor in a newer gas furnace, will need to be addressed by a professional in heating system repair in Plainfield, IL

When it comes to heating, you’re better safe than sorry, so if you’ve checked all the above possibilities and haven’t resolved your problem, reach out to us.

Call J&A today, Sleep-tight tonight!

Comments are closed.

Sign Up For Our Newsletter: