10 Questions related to Heating systems repair

Oct 29, 2022

10 Questions related to Heating systems repair

10 Frequently Asked Questions about Heating System Repair

W  hile your furnace is designed to have a long, useful life, there is a chance that something will go wrong with it. When winter weather arrives, hundreds of people call their local furnace repair experts because of a problem with their heating system. While you will want to get your furnace repaired as soon as it’s stopped working, there are some things you can look for to diagnose issues early, possibly saving you on a more expensive furnace repair or replacement.

We have listed below 10 of the most common furnace repair related questions. Read on for advice on how to repair and fix future furnace problems.

1. Is the HVAC Thermostat working correctly?

One of the most common furnace problems is a malfunctioning thermostat. Your furnace might not produce heat if the thermostat is not turned on or set to “heat,” or if the temperature setting on the thermostat is too low. If you are concerned about your furnace, one of the first things to do is take a look at the thermostat to make sure it is turned to the appropriate setting.

Also, without proper power to function, the thermostat won’t work. Like any piece of electronic hardware, the thermostat needs its batteries to function. Without charged batteries, the temperature will not be monitored, and the HVAC system won’t receive the message to turn on.

2. Are the HVAC air filters clogged/dirty?

Your furnace’s air filter prevents dust and debris from traveling through the ducts and blowing into the rooms of your home. Ideally, you will replace the filter regularly, at least once during the winter season or monthly, if you have pets or a large family. When the filter does not get replaced often enough, it can become clogged. The build-up of dust and debris restricts the airflow from the furnace, making it seem as if the equipment is not producing any heat. Replacing the air filter might be enough to fix the issue.

3. Faulty Ignition or flickering Pilot Light?

Your pilot light is essential to your furnace functioning properly. If you notice that it’s flickering or is of a yellow colour, then it could mean that there’s excessive carbon monoxide in your gas furnace. Any change to your pilot light should require a call to your local HVAC technician.

4. Why is the Furnace not switching on at all?

If your thermostat is operating and its settings are correct, your furnace will switch on and produce heat once it gets the signal from the thermostat. But if you have noticed that it is not turning on and it is getting a bit chilly in your home, there might be something wrong. As with other furnace issues, the problem might be a quick fix or it might be a sign of a larger concern with the heating equipment.

For example, your furnace is not going to turn on if the circuit breaker is turned off. If the equipment is not working, take a look at the breaker box and try to flip the switch labelled “furnace.” That might be all you need to do to get things started again.

5. Malfunctioning Blower Belt?

Your blower belt is a part of a motor that helps your furnace’s fan run. Unfortunately, these will occasionally start to fray or break. This is often noticed by a high-pitched squealing sound from your furnace while it’s running. Replacing this belt will help improve the efficiency and performance of your fan. Any blower related issues require a call to your local HVAC technician.

6. Why is the Furnace making loud noises?

From rattling to screeching, there are plenty of noises your furnace can make. Some noises can be a sign that something is up with your system and that the equipment needs to be inspected, repaired, or potentially replaced. For example, if your furnace is making a knocking noise or the furnace is making a rattling noise, that could be a sign that something has come loose and needs to be tightened or adjusted. If your furnace is making a loud rumbling noise, there might be fuel left in the combustion chamber after the system has shut off. In either case, you will want to turn off your furnace and call in a technician to take a look at what is going on.

7. Cracked Heat Exchanger?

Your heat exchanger separates the warming flame from the air, keeping your furnace running safely. A cracked heat exchanger hampers your furnace’s ability to do its job and it can allow deadly carbon monoxide to seep into your home. If you even suspect your furnace has a cracked heat exchanger, call a furnace technician to diagnose the issue. This usually requires the replacement of the heat exchanger.

8. Why is the Furnace leaking water?

High-efficiency furnaces have cool exhausts, meaning they produce condensation. Because of this, these furnaces are installed and channelled to a floor drain. The leak most often occurs when the condensation tubing becomes clogged or has a break in the line. Or, your floor drain is clogged and the water simply has nowhere to go. If that happens, your best option is to call in a technician to investigate.

9. If the Furnace is blowing cold air instead of hot?

When a furnace starts to blow cold air, it is a matter of concern. The first place we recommend you investigate is your furnace’s fan setting. If your fan is set to “on” your furnace blower is running even when the furnace isn’t producing warm air. To correct this, change the fan setting to “auto.” This ensures that the blower only runs when the furnace is actively heating the air.

The next common cause of cold air from your furnace is one we have already talked about in one of the questions above: the air filter. Dirty air filters are often to blame because they restrict airflow to the furnace’s heat exchanger, causing your furnace to shut down and cold air to build up. Just replace your air filter and you should start to feel warm air filling up your home.

10. Why does the Furnace Keep Turning on and off?

As a furnace heats your home, it typically cycles on and off, trying to maintain the temperature set on the thermostat. Depending on the programmed temperature and the outdoor temperature, a furnace might cycle on, heat the room or home to the desired temperature, then cycle off again several times an hour.

If a furnace starts short cycling or turning on and off frequently, without ever reaching the set temperature, that is usually a sign that something is wrong. During a short cycle, the furnace will only run for a couple of minutes before it turns off again. Often, the cause of a short cycle is a lack of airflow in the furnace, which causes it to overheat. Furnaces have safety switches built-in that will shut down the system if the temperature gets too hot. You will need to call a technician to take a closer look.


Although checking the thermostat and circuit breaker are things you can do on your own to see if they correct the problem with your furnace, there might be times when the issue requires attention from a trained HVAC technician . If the power is on, the thermostat is functional and you have recently replaced the air filter, you might want to call and have a professional come out to take a look. It is not recommended to try and repair anything on or in your furnace yourself, as it could be dangerous if you are not professionally trained to work on HVAC equipment.