Furnace Troubleshooting Guide

Furnace Troubleshooting Guide

It never fails! First cold night and you to go flip on the furnace and guess what? Nothing happens! Don’t you hate that sinking feeling! The uncertainty of it all. No heat, late at night, you’re thinking that if I call a technician at this hour of the night it’s going to cost a fortune!

Hence the importance of doing routine maintenance on your HVAC System. But if that slipped your mind, don’t panic. Hopefully, we can give you some things to troubleshoot to see if you can get some heat going until AIR4U can arrive.

Troubleshooting Tips

A lot of times, troubleshooting your HVAC system is starts by reviewing the simpler issues like making sure the thermostat is set properly and the batteries are still good. After you’ve gone through the basics and you feel the issue is more complicated, then call an HVAC professional. In the meantime, you can check on the following yourself.

1. Make Sure the Thermostat Is Set

Confirm that your thermostat is set on ‘HEAT’ and the temperature is positioned where you want it. Many times we don’t adjust the settings coming out of the summer season and the thermostat is still set to ‘COOLING’ mode. If the thermostat is set properly, turn it up a few degrees to see if that makes a difference.

2. Change Thermostat Batteries

If you have a battery-powered thermostat, make sure its batteries are changed routinely. The thermostat cannot communicate with the furnace if the batteries are not working properly. Change batteries to see if that solves your problem.

3. Check Circuit Breakers

Locate your fuse box and look for the switch marked “furnace.” If no such marker exists, then look for the switch flipped opposite of all the others, and then flip it back.

Furnace Troubleshooting Guide

4. Check Fuses

You could have a blownFurnace Troubleshooting Guide fuse. Without being overly complicated with all the different types of systems, just know that you should have additional fuses other than the switch in your fuse panel. You should have a disconnect box attached to the side of your house next to your condensing unit or even up on the roof if you have a package unit that also has fuses.

These are high voltage fuses and if you are not familiar with them or the safety precautions needed to change them, we HIGHLY recommend that you call a professional to change them for you.

You also may have a low voltage fuse blown on your control board in your furnace compartment. Try checking that as well.

5. Replace Furnace Filter

Dirty filters affect the airflow and can shut off your furnace (especially newer gas furnaces, which turn off to avoid overheating). Furnace filters should be changed every 30-90 days to allow for proper airflow.

6. Check Fuel Source

If you have a combustible fuel burn system take care with this troubleshooting tip since gas or propane is involved. See if your valve was somehow turned off by accident. If you smell gas, contact an HVAC professional immediately to handle any natural gas leaks, as they can be dangerous.

Furnace Troubleshooting Guide

7. Check Pilot Light

If you have a combustible fuel burn system take care with this troubleshooting tip since gas or propane is involved. Like a gas water heater, your furnace also has a gas pilot light that may have to be relit. This is one of those things that if you have never done it before, I would recommend calling a professional at least your first time so they can show you how to do it properly.

Furnace Troubleshooting Guide

When to Contact an HVAC Professional?

If the furnace troubleshooting checklist did not alleviate your issue or you ran into one of the problems below, then call your local HVAC professional to get your furnace working again.

  • Noisy Furnace: If your furnace is clanging, banging, or making other noises, this could be a symptom of a serious problem. Call a professional.
  • Gas Line Issue: Leave a natural gas problem to the professionals since it can be dangerous.
  • Faulty Pilot Light or Furnace Flame: If your pilot light keeps going out, contact a professional, as the ignition switch may be installed incorrectly.
  • Improperly Installed Furnace: If your furnace was installed wrong, then it could be leaking gas or carbon monoxide into your home. Again, call a professional.

Experienced professionals can troubleshoot these furnace problems and get your home warm again.

Furnace Faqs

How do I Reset my Furnace?

Most furnaces have a reset button on the top, on the side, or on the bottom. Check your owner’s manual for the exact location. Each manufacturer will have its own.

Why is my Furnace not Coming on?

If your furnace is not on and you have tried the furnace troubleshooting tips above, then contact your local HVAC professional.

How do you Know if your Furnace went Out?

Referring to the furnace’s manual for its location, see if your pilot light is on. The main gas line coming into your home may be off for some reason; a call to your gas company should alleviate this. If you are having furnace problems, plenty of furnace troubleshooting tips exist.

That said, if they do not work for you or if you feel uncomfortable completing any of them, give your local HVAC professionals a call. They can assess any issues and then repair your furnace so your home can be cozy again.

New System Quote