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Your Furnace Is Out! 9 Things to Check before Calling the Professionals at Schneller


No one wants to pay for a service call to find out that the problem was something simple that you could have fixed yourself. The heating and cooling experts at Schneller Knochelmann Plumbing, Heating & Air have created this quick troubleshooting checklist for our area homeowners. Nearly a quarter of all service calls could be avoided with easy fixes that cost you very little or nothing at all. Check these items before calling us to rule out any easy fixes and save yourself the cost of a service call.

Start with the Thermostat

Make sure the Thermostat Is Set to “Heat” – This may sound silly, but the switch at the bottom of the thermostat can get bumped to “Cool” which means your furnace will not turn on. If it is not set on the heat setting, switch it and make sure the temperature is set high enough to engage the furnace.
Check the Programming Settings – Make sure the program is displaying the right day and time, as well as a.m. and p.m. settings.
Control the Temperature Manually – If you can’t make the program settings work, you can bypass them altogether. Simply enter the temperature you want with the up/down control button and then press and hold it. That will override any settings on the thermostat to rule out any thermostat programming problems.
Check the Batteries in Your Thermostat – Some thermostats are wired into your home’s electrical system. Some run on batteries. If the batteries are dead in your thermostat, it can’t communicate with the furnace. Replace the batteries and see if that solves the problem.

Check the Furnace Filter

A dirty filter can cause heat and pressure to build up in your furnace. If enough heat and pressure build up, the furnace may stop working completely. Newer more energy efficient furnaces are sensitive to this problem. Replace the filter and see if this solves the problem. BTW-you should replace your filter once a month. TIP – listen for a whistle. Dirty filters cause the furnace to work hard to pull air through which can create a whistling sound.

Related Read: High-Efficiency Furnaces and Air Conditioners-How Much Will They Save You?

Make Sure the Furnace Is Getting Electricity

Switch the thermostat to “on” from “auto” to force the fan to operate. If the fan comes on, you’ve got power. If it doesn’t, your furnace may not be getting power.

Check the Furnace Switch

There is a power switch that looks like a light switch either on your furnace or on a wall nearby. All furnaces, no matter what age or type, have one somewhere. Flip the switch and give it a minute or two to see if it turns the furnace on. Sometimes there is a second switch at the top of the basement stairs. It is common for this switch to be accidentally turned off. Also check to make sure all access panels and doors on the furnace are closed all the way. Some furnaces have emergency cut-out switches that are activated when a door or service panel is removed or not closed properly after service.

Check the Pilot Light

If you have an older gas furnace with a pilot light (a flame that is on all the time) look inside your furnace to see if it is on. If not, follow the instructions on the furnace to re-light the pilot. If after following the instructions, the pilot will not light or stay lit, it could be a broken gas ignitor. Call a service technician.

Check the Circuit Breaker

Find your breaker box (usually downstairs or in the garage). Look for a switch that is in a different position than the rest. This is the breaker that’s been thrown. Push it all the way one way and then back to match the position of the rest. If it clicks out of position again, you may want to call an electrician to see what the problem is.

Check the Drain Lines

High-efficiency furnaces can drain off several gallons of water a day. If these drain lines get clogged with sediment or mold, your furnace will shut down. If the drain hose looks dirty, remove it, fill it with a mixture of bleach and water (25 percent bleach), then flush it after several minutes.

Check Vents for Blockage

If you have a furnace that vents out the side of the house, make sure nothing is blocking the intake or exhaust. Leaves, small animals making nests, or even excess snow can clog vents. Make sure they are clear.

If none of these seem to be the problem, call the furnace experts at Schneller Knochelmann Plumbing, Heating & Air and we’ll come fix it in a flash. Call us at 513.407.4424 or 859.757.1877.

Is your furnace on its last leg? How do you know? The talented heating and cooling technicians at Schneller have created a handy checklist titled, “You Be the Tech Check” that will help you determine if it’s time to call us to discuss replacement options or if you may get a couple more years out of your furnace and air conditioner.

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