No Heat? 5 Things to Check Yourself

Tips and Tricks

no-heat

“The weather outside is frightful.” That’s when you’re glad you had your central heating system checked and serviced in the autumn. It’s a good feeling to know that it may be rainy, freezing, blizzardy, windy horrible weather outside, but that you’ve got your own comfortable ‘weather’ inside. And several months ago the hardworking folks here at Best Heating & Air visited our neighbors all over and around Natick MA to make sure their heating and air systems would make it through the winter.

But… what if you can tell that there’s something wrong with your forced air furnace? Maybe you can hear the thermostat click, the furnace starts up, you’re all ready for some toasty warm air, and then… it just shuts down. Or maybe you wake up and you can see your breath. Not good. Here are 5 things that you should check before calling a trusted HVAC service company.

  1. Air filter
    Don’t be embarrassed if you fix your problem with this first step. Check to make sure the air filter is clean. An extremely dirty air filter can block air flow, and the furnace won’t have enough air flowing through it to move the heat. As a safety feature it is designed to shut down if it gets too hot. So replace the air filter if it seems dirty, and make sure all registers are open and not blocked by furniture, curtains, or other items.
  2. Power
    Check to make sure power to the furnace is on. Even gas furnaces need electricity to work. There should be a switch close to the furnace. Did someone bump it and turn it off? Check the fuse or circuit breaker at the electrical panel. Did the fuse blow or the breaker trip off? Replace the fuse or reset the breaker. If it happens again right away, it’s time to call in someone you
  3. Thermostat
    Check the settings on your thermostat. Make sure it is “On”, turned to “Heat” or “Auto” mode, and the temperature control selector is set higher than the current room temperature. The fan switch can be set to “On” or “Auto”. As a test, try raising the thermostat to its highest temperature setting to see if the furnace comes on.
  4. Gas valve
    Make sure the gas supply to the furnace is fully open. You could also check to make sure the gas control valve inside the furnace is open. If you smell gas, don’t turn any lights or fixtures on or off, leave your home immediately and then use your mobile phone or a neighbors phone to call the gas company for emergency repair.
  5. Pilot light
    Finally, older model furnaces have a little flame that is always lit, which then lights the main furnace when your home needs heat. Has it blown out? Check out our blog on how to relight a standing pilot on a gas furnace. Do you light it, but can’t keep it to stay lit? Then the most likely cause is a dirty or broken sensor, called a thermocouple. This small probe is mounted directly in the flame of the pilot light to tell the furnace whether the flame is lit or not. If that sensor is not working then there is no way to see the flame and the furnace shuts the gas valve to prevent gas from filling the house. If you feel comfortable, remove that probe/sensor and clean it with some fine-grit sand paper. Be very careful not to damage it, and don’t kink the flexible wire-like tube that comes out the end of it. After you re-install it, try again to light the pilot. If it still won’t stay lit, then call a professional service company to help you.
    Newer model furnaces don’t have a pilot light that is always lit, but automatically light each time the furnace needs to heat your house. These furnaces are more reliable, but also more complicated to fix. One simple step to try yourself is to turn off the power to the furnace for about a minute, and then turn it back on. That may reset the controls and let the furnace start up. Still nothing? Time to call your preferred heating and air company.

Give us a call at (800) 240-2823 and we’ll be happy to help you. We 100% guarantee your satisfaction with our service. Is there something else that you want help with? Visit our Ask an Expert page, fill out the form, and our resident expert will reply quickly.

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