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AC and Heating Tip from AC Express

Most Common Furnace Problems

Most Common Furnace Problems

Modern day heaters are the result of decades of machinery innovation that is in and of itself the result of thousands of years of slowly developing ideas about how to artificially change the temperature of our dwellings. Nowadays we take our heating in Austin for granted but the ability to be perfectly warm and content inside your home even when it gets to below freezing outside is really a remarkable feat. Day in and day out, while you’re sleeping and while you’re awake, your furnace heats your home reliably and consistently.

So it’s no surprise that with all the work that our furnaces put out they sometimes develop issues. Some problems that can fall upon furnaces are more common than others. The most common ones are worth knowing about because if you understand what the problem might be then you have the most important thing to have when it comes to solving any problem, knowledge. So in this tip we’re going to look at some of the most common problems that can plague furnaces, the causes of these problems, and a little about how to approach these issues.

Frequent Cycling

Frequent cycling is what we call it when an air conditioner or a furnace switches on and off more frequently than it should. The way furnaces work, the thermostat senses the temperature inside and once that temperature drops below what temperature you have set the heater for the thermostat sends a signal to the furnace, turning it on. Then when the thermostat senses that the temperature has reaches the desired state it sends another signal turning the furnace off.

If the furnace is going through this cycle of turning off and on more often than it should it could be because of several different causes but the result is the same: you’ll be using more energy than necessary and your bills will go up. In addition, more wear and tear will happen to the heater if it is starting up more often.

This is also sometimes referred to as short cycling. If you are new to the home, you may not have enough information to know whether this is a new problem or if it existed before you moved in. Although you may have tested the system during your walkthrough, many people just do a brief check to see if HVAC equipment turns on. If you’ve lived in the home for some time, this on and off activity could signal a need for heating repair services. However, you can do some troubleshooting first to make sure that it’s not a simple and easily solved problem. The solution is going to depend on the cause of this problem.

Short cycling can be the effect of many different causes. System sizing could be at the root of the problem, but if your unit has worked well in previous weeks, months or years, then it’s unlikely that sizing is the issue. If you’ve just moved in and you inherited this heater or you got a new one and it was installed by a subpar contractor then sizing could be the cause. A system that’s too big for the house it is heating is going to put out too much heat too quickly causing it to go through short cycles of off and on. This could be a problem if you are new to your home, but it’s still wise to check for other solutions before calling for service.

One of the most common problems contributing to the frequent on and off activity is a dirty air filter. Check your filter to be sure that it’s not so caked with dirt that airflow is restricted. Restricted airflow means your furnace is having to work extra hard to provide you with warmth and if it isn’t up to the task you may just find that your home never reaches the target temperature before the furnace shuts off. This ultimately causes more frequent cycling. Replace a dirty filter and try your heater out again. If the filter doesn’t solve the problem, check your thermostat settings and battery. It could be an issue not with the furnace itself but with the signals that the thermostat is sending to it. A bad battery could affect operation of the unit, causing the call for heat to be disrupted. A bad thermostat could also be a source of this trouble, but an Austin heating professional will need to verify this.

No Heat

This is the ultimate heating disaster, a furnace that has stopped giving you heat completely. This could take one of two forms, either the furnace is blowing air but not heating it, or the furnace is neither heating nor blowing air.

Let’s talk about a furnace that blows air but there’s no heat first. Before you go calling an HVAC technician to come and sort out the issue, check the obvious and easy to solve potential causes first. First you’ll want to check the thermostat. Make sure the thermostat isn’t in the “fan” only mode. If your thermostat’s fan setting is set to “on”, the furnace blower will constantly run even when your furnace isn’t heating the air. You want your thermostat to be in “auto” mode which means the fans only turn on when the furnace is producing heat. This is the most likely cause of a blower not blowing warm air if it only happens sometimes and hasn’t been a permanent issue.

Another possibility is that your furnace overheated. If so, the limit switch, a furnace safety device, turned the furnace burners off. The blower keeps blowing to cool the furnace down to a safe level. So what causes the furnace to overheat? Most commonly, a dirty furnace air filter. The dirty air filter will block airflow, causing the furnace to run longer to heat your home until it overheats. This is also an easy fix that you can do by yourself. Just replace the air filter and if it was dirty it was probably your culprit. Then you’ve got the problem solved.

It could also be an issue with the pilot light malfunctioning. If you’ve checked the thermostat and the air filter and there’s no issues there then try relighting the pilot light. You can look up videos on how to do this but the basic instructions are as follows: Find pilot light assembly. It typically has a gas valve with on, off, and pilot settings. Turn the valve to off and wait three minutes. Switch the valve to the pilot setting. Hold a lighted match to the pilot opening while you push the reset button on the pilot control panel. Keep this button pressed until the pilot flame burns brightly, then set the valve to on position.

If your furnace isn’t blowing air at all, hot or cold, then you’ll want to again check the thermostat first. You likely already have if you’re seeking out a solution to this problem but it’s worth mentioning. Make sure you set your thermostat higher than the temperature of the house currently. Make sure that it is set to the “auto” setting and wait a few minutes. If the furnace hasn’t turned on then you’ll have to continue troubleshooting.

The issue could be electrical as well so next you’ll want to check your circuit breakers. Check that the circuit breaker for your furnace is not off, but also understand that it is not uncommon for your blower motor to have a separate circuit breaker, so check this as well. Next, go to your furnace and check on the furnace itself and surrounding walls for another on/off switch or circuit breaker and ensure that it is on as well. If any of these are off, turn them on once (and only once, for safety) and allow your system to run. If they trip off again then this is a sign that there is a problem with the wiring of your system and you will need to call out your local Austin heater repair professional. Do not keep resetting faulty circuit breakers to your furnace as this is dangerous and could start an electrical fire.

Of course, the issue also could be with the furnace itself. If the blower motor does not start and you’re not getting any air blowing out of the registers, it could be the result of a bad blower motor. A failed blower motor will often be accompanied by a bad odor like burning plastic or rubber. If the fan does not operate automatically after the burners have ignited, or after turning the thermostat fan switch to the "on" position, this may indicate either a bad blower motor or a bad capacitor. This issue will have to be dealt with by an HVAC professional.

High Energy Bills

This furnace problem is a little more nefarious than the others simply because you might not notice it until it has already cost you a significant amount of money. Sometimes you might find your gas and/or electricity bills are going up slowly month by month. If you’re in the middle of the cold season you might think this is just a natural progression as the heater becomes more necessary and has to stay on longer. But it could also be an issue with the energy efficiency of your furnace that is causing the unusually high energy bills.

The most common cause of high energy bills is a lack of regular furnace maintenance. In fact, of all the furnace problems, a lack of furnace maintenance is the biggest culprit. When it comes to efficiency, a well-maintained furnace will always outperform its dirty, out of tune counterpart. You should plan on having your furnace professionally cleaned and maintained at least once a year to maximize on efficiency and performance. Units that run efficiently use less energy. When you are using less energy, you're spending less money.

Another common cause of this issue is just that your furnace has simply outlived its most efficient years. Today's newer furnaces operate much more efficiently than the older units of yesterday. If your unit is older than 15 years, you should consider purchasing a new furnace. The savings over the long run will outweigh the cost of the upgrade.

Common Furnace Issues and Heating Repair in Austin

As much as we don’t like to think about, there are many things that can go wrong when you’re dealing with devices as particular and sophisticated as modern heaters. But some furnace problems are more common than others. Above are some of the most common problems that we get calls about all the time. Sometimes the fix is easy and sometimes it requires the help of a professional.

At AC Express, we pride ourselves on our ability to swiftly and painless diagnose and solve any issue that your heater might face, common or not. If you’re looking for heater repair in Austin then you don’t have to look any further. We operate all around the Austin area, from Cedar Park and Georgetown to Leander and Liberty Hill. Call today!


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