Heating Troubleshooting

• Have your batteries been changed recently? (Does not apply to wifi thermostats which generally don’t have replaceable batteries)
• Is the thermostat set for “Heat” and not in the cool or off position?
• Set the temperature for 3 degrees above the current room temperature

Is the furnace running and heating now?

• Look for a small viewing window generally on the lower door of the furnace, you may need to remove the outer door on older Carrier & Bryant Units.
• Look in the window for a blinking LED light. The LED lights will generally blink out a code in a series of long and short flashes, or in a series of different color flashes.  Record the pattern on a piece of paper.
• This code will help us diagnose the cause of the lock out, or point of failure.

Did you record the code?

• Turn the switch to the furnace off, wait 3 seconds, and turn it back on.
• Now wait 3 minutes and let us know what is going on.

It has been 3 minutes now. What has the furnace done?

Try this:

• Check your home’s electrical panel. Flip the furnace’s circuit to “off” and then “on” again.
• Look for a switch (like a light switch) near your furnace and make sure it is set to “on”.
• Some of the older switches to the furnace have a buss fuse in them and they can go bad from time to time.  Try replacing the fuse and turn the furnace switch back on.

Did that solve your problem?

• If it has been longer than a month or 2 replace the filter with a clean one
  • A dirty air filter will reduce the air flow going through the furnace and can cause the furnace to overheat
  • Once the furnace is overheated it will shut down the burners and turn the fan on non-stop.
• Look for a blinking LED light in the bottom of the furnace that you should be able to see through a small viewing window.  It will likely be blinking in a series of short and long blinks.  Record the number of short and long blinks on a piece of paper.
• Turn the power off to the furnace using the switch, wait 3 seconds and turn back on.
• Wait 3 minutes and choose the best answer below.

Is the furnace running now?

Did the blower for the furnace turn on instantly and the furnace hasn’t done anything else for the last 3 minutes?

Although not difficult to reset, locating the limit switches can be an issue.  We would recommend scheduling an emergency service call unless you are handy at reading a wiring diagram.  There are 3 limit/roll out switches in most furnaces.  Any one of these can be the culprit.

Unfortunately you probably have a motor that burned out, or a circuit board shorted out.  Please call our office for emergency service.

The hot exhaust you are smelling is likely from a cracked heat exchanger.  A crack in the heat exchanger allows the exhaust your furnace produces during combustion to mix with the air being circulated inside your home.  Exhaust may have carbon monoxide in it and is not safe for you and your family.  Please turn the furnace off and request emergency service.

There could be a dangerous gas leak in your home. Turn off your furnace immediately and contact us.

But for how long?  When you turn power off to the furnace it clears any lockout messages in the system.  This allows the furnace to attempt to ignite again.  There is more than likely an underlying issue that caused the lockout in the first place and we strongly recommend contacting us for a non-emergency service call

Please turn off your system and get professional help from our knowledgeable service staff.

Glad we were able to help you solve your problem. We’ll be here if you need us again.

The immediate emergency is gone.  However, there are likely underlying factors that contributed to this.  When you cycled power to the furnace you cleared out the soft lock out code and the furnace is now running with no memory of this.  There is more than likely an issue that should be identified and fixed before this happens again.

We strongly recommend you call or schedule a non-emergency service call for us to identify any conditions present that may keep you from having a hassle free heating season.

Your heat exchanger most likely has some funk that has built up on it over the off season.  The smell should burn off and dissipate.  If it doesn’t go away after a few hours please call us for service so we can diagnose and correct the smell.