Everything To Know About Furnace and Heating Systems

At Southern Comfort Mechanical, we understand that staying warm and comfortable is essential in our day-to-day lives, and we expect it to work without a second thought. We appreciate what it means to not have heating in our homes or offices. It wasn’t easy to function and get things done during the ice storm and power outages in Feb 2021.

The Objective of This Article

Give an overview of the heating system in our homes in the greater Lewisville area. The system parts and what they do, the different variations and types of furnaces. The major components and their role in the equipment. The most common issues, what it can take to get resolved, and any troubleshooting tips to help homeowners. This includes furnace/ gas heating/ heat pump/ air handler/ thermostat/ electric heat.

What Does a Heating System Do and How Do Furnaces Operate?

The heating system is called AC or air conditioning, furnace, boiler, or heat pump. They are generic terms that are referred to as the ability of the system that heats our home. In our homes, we are less dependent on the heating system to heat versus the system’s ability to cool as other sources can heat our homes. It’s Texas, and the sun warms our homes the majority of the time. Even in the winter, the sun will add heat to our homes.

Many homes have fireplaces, there are portable electric room heaters, cooking on the stovetop or oven will heat our homes. Sources which the ac works to remove in the summer months to keep us cool.

Furnace – the primary function when the thermostat senses the temperature is below its setpoint sends a signal to the furnace to turn on. The furnace starts up and burns gas which warms a heat exchanger and is transferred into our living space through the vents around our homes.
Heat pump – is more involved as it uses multiple parts and is a more complex system. When the thermostat senses the home requires heat, the signal goes to the outdoor unit. The heat pump, which turns on and pulls heat from the outdoor air, passes it into the Freon and circulates it into the air handler. The air from our home is warmed by the air handler and pushed into our homes via the vents.
Air handler – this is matched with a heat pump to warm the indoor air. The hot Freon from outside is passed through the evaporator coils, which act as a heat exchanger to warm the air as it passes over its surface.

When the home requires a lot of heat, there is also a bank of electric heat elements which can be turned on to supply extra heat or emergency heat. These are called heat strips.

Electric – another less common system is to have an air handler with heat strips. When the home calls for heat, the electric heat strips warm-up and heat the passing air returning into the conditioned space.

Hydronic heating – takes water pumped from the outdoors, which is either buried to a target depth that pulls heat from the earth or solar collectors and passes this into the home via an air handler or underfloor piping. (This is not a technology that SCM works with).

Inside a furnace, there is an assembly of components. A number of them are related to safety as burning gas creates carbon monoxide, which is high enough concentration will cause asphyxiation. The gas is odorless and heavier than air.

Safety switches – are around the door to check that all the doors are in place to protect anyone from getting burnt on the hot surfaces when the system is running.
Control board – determines the system’s function and coordinates the components’ tasks, telling them when to start and stopping if there is an issue. The more complex the unit, the greater the array of parts the board manages. Taking inputs from the different sensors and using the built-in operation to run and stop the furnace operation.
Gas valve – controls the flow of gas into the furnace, which is turned on and off.
Inducer motor – runs before, during, and after the heating operation, like a vacuum cleaner. When it is running, it pulls gases out of the heat exchanger and passes them to the flue pipe to remove them from home.
Flue pipe – connected to the side of the furnace. This is the chimney for the furnace that removes gases from your home.
Burners – the gas passes through the trumpet-shaped metal assembly. There are 2 to 4 typically dependent on the heating capacity of the furnace. In the end, the flame is ignited with the flame burning inside the heat exchanger. Older designs have a different configuration and have rows of small flames running underneath the unit to pass heat into the heat exchanger.
Heat exchanger – the flame burns inside the shell of the assembly. There are different assembly configurations, but all create a hollow tube with the flame burning at one end and the exhaust gases leaving the other end. The flame heats the metal or aluminum, and air passing across the surface is heated. There is a flue pipe on an 80% furnaces – think of it as $8 to $10 in gas is transferred to the air entering back into your home, and the remainder is exhaust gases leaving via the flue.
Blower motor – this works year-round in cooling and heating mode and drives the blower wheel. There are two types of motor PSC and ECM. The ECM has higher efficiency and a built-in electronic control. Higher-end furnaces with variable speed controls have had ECM motors. With newer regulations, the ECM motors are in the majority of furnaces.
Blower wheel – this part moves the air through the system running in cooling and heating, pushing air across the heat exchanger and evaporator coil and back into the conditioned space through the ductwork.
Flame sensor – a safety device that in heating mode is confirming there is a flame present. The part is a ceramic tube to withstand the heat. As the flame’s resistance changes the sensor’s heat, there is a difference between the resistance when a flame is present via no flame. The resistance is fed to the electronic control board.
Air filter – the system passes air through the filter before the unit or at the air returns to remove dust and dirt from the air before passing it into the system equipment and back into the ductwork. The filters are key to the system’s performance. The more clogged or dirty, the less airflow moving through. If the airflow is too low, there is a risk of the heat exchanger overheating. The sensor will shut off the heating if high-temperature limits are tripped to protect it from damage. A heat exchanger may crack if it exceeds its designed operating temperature.
Thermostat – senses the room’s air temperature and sends a signal to the system to turn on or off based on the type of system. The higher-end will have more complex capabilities to turn the heat off earlier than the air as it anticipates when to turn off and on. Communicating fault codes if it detects the system is not running properly.

How a Heat Pump System Works

The outdoor unit is the heat pump – taking heat from the outside when in heating mode and cooling mode the unit runs in reverse and takes heat from home and passes it to the outdoor air. The heat pump works in tandem with an air handler located inside the air conditioner.

Heat pump – the compressor placed at the center of the unit pumps the Freon around the circuit via copper pipes connecting the air handler evaporator coil. The Freon leaves the compressor as hot gas and is pumped to the indoor evaporator coil in heat mode.
A condenser coil is a series of thin tubes embedded in spines on or inside a lattice structure of other manufacturers. The Freon in heating mode is pumped in at the bottom and heated by the outdoor air passing across the surface.
Reversing valve – controls the direction of the Freon/ refrigerant flow. The direction is determined by the mode of operation, heating, or cooling.
Defrost board – when the heat pump is running in heating mode, a large volume of air is pulled across the evaporator. Ice will build upon the condenser during operation when the outdoor air temperature is low below 40 F. The defrost shuts off the fan to thaw the ice to prevent the unit from freezing over and stopping the airflow.
Control board – the electronic circuit that controls the unit’s operation based on inputs from the air handler calling for heat or coil, the defrost board. The more complex the unit, the higher the number of sensors, including temperature sensors, current sensors, which makes the unit operate more efficiently.
Fan and fan blade – the motor to turn the fan located at the top of the housing. This drives air through the condenser coil by drawing air through and across the coil to absorb heat which is then blown out the top of the unit.

Inverters with high efficiency require precise speed and control. The compressor speed from 0 -100% is dependent on the demand for heating. A transformer changes the voltage of the input to a target output required by the unit.

Sensors – temperature and pressure readings from different areas around the equipment fed to the unit electronic control board. Temperature sensors are included on higher efficiency units taking readings on outdoor temperatures, Freon temperatures at key locations in the circuit. Pressure sensors are located at key points in the Freon circuit. Current sensors are reading the amp level on the fan motor or compressor.

What is an Air Handler?

The evaporator coil is the aluminum lattice structure that conditions the air passing over the surface. When the unit is in heat mode, it flows the hot Freon from the heat pump. The hot Freon enters one end and leaves the evaporator in a cooler state, transferring heat to the indoor air.

Control boards are the electronics that manage the operation of the air handler by taking input from the thermostat heat fan only. Depending on the complexity of the air handler, the more inputs and sensors to take feedback and manage the function such as ramping the motor speed up and down, controlling the flow rate of the expansion valve, turning on and off the heat strips on demand.

Heat strips are larger versions of the windings found in a hairdryer, which are wires with high resistance to heating up when electricity is passed through them. The size of the unit determines the output of the heat strips. Typically there are 3 banks of the heat exchanger on the higher efficiency unit. The control of the amount of heat from the heat strips is higher, with 1/ 2 or 3 turned on. The order in which they are turned on and used is rotated, so the strips are evenly used.

Blower motor – this works year-round in cooling and heating mode and drives the blower wheel. There are two types of motors PSC and ECM. The ECM has an in-built electronic control to control the operations and also has higher efficiency than the PSC type. Higher-end furnaces with variable speed control generally have ECM motors. Besides, with newer regulations, the ECM motors are in the majority of furnaces.

Blower wheel – this part moves the air through the system running in cooling and heating, pushing air across the heat exchanger and evaporator coil and back into the conditioned space through the ductwork.
Air filter – the system passes air through the filters which cleanse the airstream before sending it back into your home’s ductwork. The filters are key to the system’s performance. The more clogged or dirty they are, the less airflow through them. If the airflow is too low, there is a risk of the heat exchanger getting overheated. The sensor will shut off the heating if high-temperature limits are tripped to protect it from damage. A heat exchanger may crack if it exceeds its designed operating temperature.

What Are The Different Types of Heating?

Texas versus other parts of the US – In the Dallas area, there is a low requirement for heating compared with other regions of the country. The focus of an HVAC system here should be on the cooling capability due to the extensive part of the year it is required.

An 80% furnace is the typical type of furnace installed to heat homes based on the heating demand and lower investment versus a 90% plus unit.

In Northern states, where 90% plus furnaces are the standard types, the heating requirements are for a large part of the year, with heating being more important than cooling.

Low Nox furnaces are required in California to meet the government legislation but are not needed in other areas. These units are CA-specific.

90% or 95% high efficiency can be installed in any home if there is a natural gas or propane supply. In the Dallas area, they are installed in homes with foamed attics. Unless required, the higher equipment cost is not typically justified.

Within the 80% furnace efficiency, there are several different configurations:

Single-Stage Heating System

These HVAC systems are still the most commonly used in the United States. A single-stage heating or cooling system means your furnace or air conditioner has only one level of heat or cold output. Single-stage thermostats are used to control these systems. Continue reading to learn more about single-stage thermostats and the features they can offer.

The single-stage will have one level of heating. This can be matched with other cooling configurations, such as two stages of cooling and one stage heating. Another common furnace is single-stage heating with a variable-speed blower.

Two-Stage Heating System

The two-stage heating systems are the ones where the compressor has two stages, a low and a high. The first or low stage will run at around 60% to 70% capability, and in the second or high stage, there is high demand for either cooling or heating. These are more energy-efficient than single-stage units as they run at the low stage for a longer time.

Communicating System

Communicating systems with modulating heat is not very common in the Dallas market. Their low heat setting is about 40% of the capability and ramps to 100% based on the heating requirement.

In these systems, the indoor and outdoor sensors communicate with the thermostat to determine exactly how much heating is needed to keep your home at the designated temperature. Thus, by matching the real-time demand for heating, the units will run for an extended period, with a low output.

Air Handler

Typically paired with an outdoor heat pump or with an AC-only outdoor condenser with the heat source coming from electric heating in the form of heat strips inside the air handler. This setup is used infrequently in the Denton and Collin area.

Heat Pump – Outdoor Unit

Heat pump systems are predominant heating systems in many Northern states, Arizona, and New Mexico. In Argyle, they are the standard type of system due to the lack of natural gas supply.

Variable speed: These systems are efficient and deliver the most significant comfort level, from 18 seers to 28 seers. They are communicating versus non communicating, which ramp up and down, stating around 10% of capability and can ramp to 100%—running a large portion of the day in heating mode, ramping up and down to match the indoor heating requirement.

Single-speed blower: When in operation, the blower fan runs at a single speed in heating and cooling modes. When in heating mode, paired with a heat pump, it will heat the air via the evaporator coil from the hot Freon. The electric component only turns on when there is large enough difference between actual temperature levels compared to target setpoint, roughly 3 degrees Fahrenheit. Still, it can vary depending on the air handler, adding supplemental heat in freezing weather when the heat pump can’t supply enough heat.

Heat strips: Triggered to come on as a backup for emergency heat when the heat pump cannot run.

Multi-speed blower – the unit has multiple blower speeds at low, medium, and high. This will improve comfort and energy usage by matching demand closer to what is needed. When there is an increased need for heating, the unit will run at the top setting then drop down in speed to help maintain efficiency.

Variable speed units – can ramp from 0% to 100% when running and fluctuate to maintain temperature, taking direction from the thermostat on the best speed to run. This is the highest comfort as the unit runs for low periods at a low level, keeping air moving within your home.

Mini-Split Heat Pumps and How They Work

Depending on the configuration, a mini-split or ductless system has an outdoor heat pump and an indoor head or multiple heads. The evaporator coil in the furnace will heat or cool the air based on the mode and pass the air directly back to the room or area without any ductwork. The system is typically high seer, although entry-level systems at 15 seers the higher end 30 plus. Conventional heat pump performance will start to reduce around the freezing point. But mini-split performance remains close to 100%, well below freezing, with the Mitsubishi hyper heat systems giving 100% down to 0 degrees Fahrenheit.

Other Features Include:

System size: As with AC systems, the size of the heating demand aligns with the size of the home. The heating and cooling are matched in the system design. If the heating capability is large, the unit will kick on and quickly hit the required temperature, then switch off. On the flip side, if the heating capability is too small, the home never gets to target temperature, even by running constantly.
Heating output: The heating output is measured in BTU/ hour, BTU short for British Thermal Units. The amount of energy to raise one pound of water by 1 degree Farenheight but is still a rather abstract measure. Furnaces range from 40,000 BTU for a 1.5 Ton AC system to around 100,000 BTU on a 5 Ton AC system for a large 2000 square feet home.
Ductwork: Ductwork is the metal or flexible ducts that run from the air handler or evaporator to the vents in the ceiling or walls that deliver the conditioned air back into the rooms.
Vents: Vents are the grills that defuse the airflow back into your rooms, forcing the air to circulate and mix. Typically they are located in the rooms close to windows and point the air towards the window, wall, or around the room’s walls. Based on the original home design or additions, there can be airflow issues, including if windows have been changed to more energy-efficient versus old aluminum that had a lot of air leakage. As a result of this, such areas can feel different from other areas of the home.

Investigations can be made to determine the potential issues including:

a grill has been re-installed in an incorrect configuration
the air balanced by adjusting the volume of air sent to different ducts
By removing/reconfiguring ducts to deliver the required volume to the target area

Auxiliary components can be added to an HVAC for specific applications to assist with comfort or address specific problems.

Zoning: Zoning is the addition of zone sensors, powered dampers, and control hardware to split up a home into zones and control the temperature within the zone. The zoning allows for slight variation from one area to another. The temperature differential allows for a few degrees between zones on the system. Unless specifically designed and sized for a more extreme temperature differential.

Humidifier: A humidifier is added to a home that is dry and requires the ability to add moisture. When heat is running, this dries out the air in our home. Some people are sensitive to low humidity levels and can have nose bleeds. Homes with grand pianos will require tighter humidity control to stop the instrument from drying out and being impacted. These operate to add moisture into the air, generally through steam. When the unit is triggered by a set point, the air is passed through the dehumidifier, and steam is added to raise the moisture level/humidity.

Air filtration: Air filtration can be upgraded to improve the air quality by removing more particles and contaminants from the air passing through the indoor unit. This can start with upgraded air filters.

Potential Drawbacks Include:

When the unit is installed, the airflow should be set up during the installation process based on air pressure readings in the system. Increasing the Merv rating on the filter can increase the pressure impacting the airflow. Higher Merv filters may need to be changed more frequently as the amount of captured particles will build up faster, reducing the airflow through the filter. If the airflow is too low, this causes the unit to start freezing up. There are OEM add-on filtration options with Trane clean effects, an electronic air filter, and pure air from Lennox.

Whole-home air purification is a level up from the filter upgrade and includes air treatment from the addition of UV.

UV light can be installed, which will treat the air that touches it when passing through the entry-level and improve by reducing the contaminants in the air deactivating bacteria. The challenge is the volume of air passing through the system because light can only effectively treat a portion of the air.

Reme is the typical unit installed by Southern Comfort Mechanical. The treated air will deactivate bacteria in the air and on surfaces that it comes into contact with. Airborne particles are clumped together to catch in the filter by ionized air.
Reme LED is the upgraded version using the same air treatment process but with LED offering a longer life of the unit.

FAQs About Heating Systems

What type of system is best to heat a garage?

The best system for a garage is a mini-split system that will provide heat in the winter and cooling in the summer. The system can be sized to meet the amount of cooling or heating deepening in the area.

What type is best for my home office/ home theatre?

The recommended solution will vary based on the location. The easy answer is to install a mini-split. There may be another solution to modify the existing home ductwork and or add zoning capability.

What type of warranty do I have on my current system?

There may be a warranty from the manufacturer. The warranty period will depend on the manufacturer, if it was registered and if you were the homeowner at the installation time. All you have to do is call the company that installed the unit from a sticker located around the equipment or call a dealer and provides the serial number. If you like to do it for yourself, go to the manufacturer’s website and enter or call them to look up the warranty on the equipment.

Why is my furnace blowing cold air? – the unit runs, but there is no hot air.

This indicates the furnace has not started to heat the air, which is a problem in the start-up cycle. To resolve this issue,

Double-check the doors are correctly installed.
If this does not fix the problem, next is to check the electronic board.
Or it could be a problem with the inducer motor having a blocked drain line and not being able to drain the water that builds up in the housing.
If the issue persists, it’s best to call an HVAC professional to diagnose and determine the repair.

What are common heating system problems?

Power switched off: If the furnace does not make any noises or attempt to start up it is probably due to lack of power access. So, check if the unit has power. It will either have a plugin, socket, or light switch. Often mistaken for an attic light, they can accidentally be turned off when leaving an attic.
Circuit boards: An electronic component board can last 15 years plus but are sensitive to dirty power if there are fluctuations in power from lighting during storms. This can strain and cause premature failure.
Blower motors: If the unit has power and goes through the start upcycles, you will hear delays interspaced with clicking sounds but still fails to fire up the motor may have failed or about to fail. It is recommended to have a professional check and locate due to the high voltage and ensure that the correct motor is installed.

Capacitor failure: Capacitors in air handlers and older finance models can fail due to wear and tear from temperature and usage.

Dirty flame sensors: If the unit makes its way through the start up cycle and fires for a few seconds then stops running this is typically due to a dirty flame sensor there is soot and carbon build-up that will need to be cleaned off the surface for it to correctly detect the flame. Alternatively, the ceramic may have cracked and broken in which case the sensor will need to be replaced.

Air pockets: Air pockets in the gas line will cause the unit to try and start up and will go through the startup sequence. Then it will cut out when it does not sense there is a flame. The system may try and start again one to 3 times depending on the type before it will electronically lock itself out. If this happens it is best to call an HVAC professional to resolve and get the unit back up and running.

No sediment trap/ water in the line: If there is water in the line this can be a result of no sediment trap. The city code in Denton and Collin is to have one fitted to trap contaminants in the gas line before the furnace this will cause the burners to splutter and or burn a different color eventually resulting in the unit failing to run.

Blocked flue pipe: The unit will try and start-up but will fail out early in the start-up process, the blockage is typically from an animal that has entered via the flue pipe on the roof examples that have been found are squirrels, birds, bird nest, insect building a nest.

Water in the inducer / Blocked drain inside the motor: When running in cold weather warm air on a cold surface or vice versa will create moisture from condensation that has to drain away. If a drain becomes clogged from particles the inducer will not startup.

Bad pressure switch: As part of the system safety there is target pressure required inside the inducer to blow exhaust out of the system/ home if this pressure is not achieved the unit will shut down or not startup.

- Limit switch temperature: Another built-in safety feature to protect the unit is limiting switches on high temperatures which will cut the unit off if it exceeds a target threshold to stop the equipment from being overheated. Limit switches can fail or protection due to another issue causes the system to overheat such as low airflow from a dirty filter or failing fan motor.

Transformer failure: The transformer can fail from an electrical surge, this is taking input voltage and converting. Dirty power can take out a transformer or failures from other components can cause the transformer to fail.

Broken/ rusted flue pipe: If the flue pipe assembly is old it can corrode from rust due to condensate inside it over the period of years. This will allow exhaust gases such as carbon monoxide to enter the home.

Pilot light is out: The pilot light is out and needs relit, on very old furnaces 25 plus years there may be a gas pilot light similar to an old stove that is used to light the burners when required. The design has moved to an electrical spark to ignite the burner. If the light is out follow instructions to relight or call an HVAC professional.

Sensor tripping: A furnace that will run for a period of time and shuts off is typically related to a sensor tripping a high limit related to another issue in the furnace. When the unit cools and or a time delay is reached the unit is able to run again until it trips again. This will require an HVAC professional to troubleshoot to determine the cause. Collecting information on when the unit runs and won’t run will assist the HVAC tech in pinpointing the root cause.

What are some common issues with a 90% furnace?

Supply air intake restricted or undersized: The unit will have trouble to start up and get running as it requires a higher volume of air to start up. This can be removing a restriction or a larger issue that can result from the undersized supply with needs to be increased.

Flooded condensate/ blocked drain: On the discharge side as the waste gas is converted to water when running there is a constant flow of water from the heating. The water needs to drain if there is a blockage the water will back up into the inducer causing it to shut off.

What are some common issues with the Heat pump system?

In heating mode, the type of service calls for units, not heating is related to these components being the root cause.

Bad defrost board: when the circuit board is not working properly to control the unit, due to a power spike or component failure on the board.
Reversing valve: The part that moves back and forward when the system is going from heat to cool.
Wiring issues: Corrosion creating bad contact the indoor and outdoor are not able to send and receive the expected voltage levels.
Condenser fan motor: A Condenser fan motor is an electrical motor and can fail and stop spinning the fan. Hail damage from a storm can impact the fan blade and cause problems from airflow or hitting the body of the heat pump.
Inverter issues: The inverter is used on the highest efficiency units to precisely control the compressor speed to match the temperature needs. These can fail in rare circumstances. The unit has a number of integrated parts of electronics and electrical leads the complete inverter is changed out.

If you are experiencing any of the issues above, contact Southern Comfort Mechanical right away or check out our service area page to find out more information on what kind of heating services we provide and what are the areas that we serve.

What are some common issues with the air handler?

Electronic control boards: Electronic control boards are often the cause of them not working due to a failed item on the board from age or a power spike.

Evaporator coil leaking: Evaporator coil leaking and the freon levels are low so there is a lack of heating capacity either reduced or none. The tubing that carries the Feon has failed due to a bad tube or a manufacturing defect requiring a coil change out.
Blower motor failure: The blower motor is failing or has failed and requires a replacement motor, rarely does it occur the failure is due to the blower wheel falling apart from a bad weld. When one weld fails it impacts the others and will fall apart.
Thermal Expansion Valve: is the metering device that controls the flow of freon into the evaporator coil. This may defect and get stuck in a position or lose pressure and will stop opening and closing to control the flow of Freon around the system.
Heat strip problems: from a broken wire are typically due to age, or an internal part of the component failing.

What are some common issues with thermostats?

Like the other parts of the system, thermostats can and do have problems, common issues that can relate to thermostats in heating mode

The screen is blank: Check the batteries and replace them if they are old. If the batteries have corroded and leaked into the circuit board the thermostat will require a replacement.

A blank screen may be the result of a drain line clog and the unit is shut off to protect the unit from flooding

Wiring problems can occur from a few causes. Age as insulation gets older it degrades and can lead to shorts in the circuit from bare warm touching another, thermostat wires can develop breaks in the wire or lose contact from coming out of a terminal screw
Thermostat failure: A bad thermostat can fail due to age, with more technology the downside is more complexity and more components

Typically a thermostat issue will require an HVAC professional to resolve, a large portion of the time the thermostat is not the culprit but appears to be.

What type of system do I have in my home?

To determine the type of unit you have in your home – first answer the following question.

When the heating is turned on do you hear a noise in the attic of the closet and the sounds of burners, similar to a gas stovetop on high from the burning flame?

If yes then you have a gas furnace and the outdoor unit will not be running.
If you do not hear a flame and the outdoor unit is running then you have a heat pump system.

(In both cases, you will hear a motor running.)

If you are not able to tell, google search the number that you find on the unit outside and or inside.
Beyond that when you have the annual heating maintenance ask your technician.

What type of heating system is best for my home?

The first question is do you have a gas supply to your home? The majority have. For the homes that do not then typically a heat pump is the best type.

For Heat pumps then it is what is your budget and comfort needs. The best comfort will be with a variable speed blower to keep the air moving.

The majority of homes that have gas, typically a gas furnace is the most effective option. For comfort, the variable speed route is best then selecting from the options on heating levels and cooling.

What type of system should I install?

Work with your HVAC professional to select the system that best suits you and determine the factors that are most important to you. Keep in mind that it is a system that includes ductwork. The air conditioner and furnace/ air handler are only part. An analogy to a car changing the engine and the gearbox to new ones will improve the reliability and performance of the car but will still have issues if the suppression is worn.

What is the lowest cost/ cheapest to run?

The lowest cost system will be a single-stage furnace and a condenser and evaporator utilizing the existing ductwork and freon lines that are properly installed.

What is the dirty sock syndrome?

This usually occurs when switching between heating to cooling in the early fall or springtime. There are certain homes that will develop dirty sock syndrome which is a smell akin to dirty socks. When in cooling mode the evaporator is wet then dries out when in heating. Bacteria develop in the wet condition which is then killed in the heating cycle giving off the smell when the unit runs. This is not the same smell as when the unit is used for the first time in the season that lasts for a short period of time then goes away. Dirty socks come daily for the window of heating and cooling.

Can heating make you cough?

Some people start coughing when they breathe very dry, heated air. This type of cough may be more noticeable when you first turn on your furnace, due to dust and other irritants that have collected over the summer being blown into the air.

What is the air temperature that comes out of the vents when heating?

Approximate air temperature from a furnace vent temp around 110 degrees F, from a heat pump around 90 degrees F it will feel much less and milder as it is closer to body temperature. When running electric heat only or the air handler is running Electric heat the air temperature will be around 100 F.

Can I run a heat pump when it’s cold outside?

The expected life of a Furnace is around 12-15 years – most replace the furnace as part of a system replacement which is around 12 years on average. A furnace can work for 25 years if maintained, problems finding parts is starting to occur after a model is around 15 years old

Are furnace fumes dangerous?

Yes, the exhaust gas from a gas furnace is carbon monoxide, an odorless heavy gas. If the flue pipe or heat exchanger are damaged and leaking you should not run the heating.

What do I do if I smell gas around my unit?

If you smell gas in the attic, calling a professional plumber is recommended. If the gas smell is from the furnace itself, we highly recommend calling our heating experts for furnace repair in Lewisville or any of the surrounding areas.

When to have it repaired versus replaced?

The furnace can be replaced as part of a whole system replacement or just the furnace. The furnace should be changed out if the heat exchanger is leaking due to a cracked or rusted-out area due to safety risk and the labor involved to change out the exchanger.

If the unit is under warranty typically it is more cost-effective to have the repair completed versus the replacement. Replacement is recommended if the unit is 15 plus years old.

If the unit is out of warranty and the repair cost is significant or there has been another large repair in the last 12 months. Like an old car or washing machine when one thing goes then another starts to fail in succession.

What are the brands of systems?

The main brands of systems are Trane / Lennox/ Carrier and Goodman with related brands Oxbox, Runtru, American Standard, Armstrong, Bryant, Dakin. At Southern Comfort Mechanical we offer Trane and related brands along with Lennox.

What is the best filter for a furnace?

The filter is the same as the AC filter, the Merv rating is typically between 8 -13. The suggested rating is to match the filter installed by the dealer. You can have a discussion with your HVAC technician during maintenance time to answer questions and help you select. If your furnace filter needs to be changed, our furnace experts in Carrollton will be more than happy to help you and guide you through the troubleshooting process.

How much does a furnace cost?

It is a case-by-case answer depending on the home and the current status is the current location up to city code or does it need to be upgraded, what is the condition of the flue pipe. The equipment with supply chain demands is increasing every few months. Lastly depends on the model of furnace desired.

What size furnace unit do I need?

The size of the unit required will relate to the amount of square footage that needs to be heated and the tightness level of the space i.e. do the windows leak air or are they low E. The HVAC professional will determine the required size with you based on the comfort level you want to achieve.

What are the two stages and modulating heating?

Two-stage heating is a low and a high setting; the low stage will be sized at 40-60% of the maximum heating capability dependent on the manufacturer’s specification and the second stage will be the remaining settings. Modulating is heating on demand where the heating capability ramps up and down to supply the amount of heat needed to meet and maintain the desired temperature. This is the highest specification of the furnace and is a rare application in the metro due to the limited amount of the year that heating mode is used. In Northern cities where heating is for a larger part of the year.

What is upflow versus downflow versus horizontal?

A typical attic installation in the metroplex is a horizontal installation – where the furnace or air handler is hung in a horizontal orientation. If the air handler or furnace is installed in a closet the orientation up flows, where the air from the home is pulled into the bottom of the unit and pushed out the top into return ducts that are in the attic returning into the home via vents in the walls and ceiling.

A downflow application is rare but is utilized when the ductwork is under the home. The air from the home enters the unit at the top, typically, in a closet with vents located high in the wall. The air passes through the air handler or furnace and then under the home and the air returns to the rooms via vents located in the floor or chases built into the walls.

Can a new system save you energy?

A new system will reduce energy usage. The amount depends on the age and condition of your current system. Based on the percentage efficiency of the furnace, the speed capability and SEER rating of the newer option will give an indication of the size of the potential saving.

Are furnaces bad for the environment?

Furnaces burn fossil fuel to heat our home, this is the area of greatest impact. The common furnace in the metro is 80% efficient, converting 80% of the input into heat the remaining 20% is lost. A 90% plus furnace converts this percentage into heat. At Southern comfort Mechanical, the removed furnace is recycled.

What are FER standards for furnaces?

Fan Efficiency Rating(FER) regulation came into effect in 2019 which required a 40% plus reduction in the watts to run the motor. Manufacturers have introduced updated furnaces with more efficient motors moving away from PSC motors to ECM motors in most models. To get the most out of your heating system, call our furnace repair experts in Flower Mound or any other surrounding areas that we serve and our team will be more than happy to explain more about the FER standards a furnace should have.

Minecraft furnace – at Southern Comfort mechanical we do not work on mine craft, the majority of the technicians will not know what Minecraft is, we are unable to help build or navigate issues on converting materials.

Propane furnace – This is a standard furnace for gas that is modified with different burner jets to be adapted to propone which has slightly different properties. Failure to modify the jets will result in a shortened life span on a few of the burner parts and more frequent breakdowns.

Can I get a tune-up for my furnace?

Yes, it is recommended that the heating is tuned-up or serviced once a year with an AC tune-up. Most manufacturers can/ randomly request proof of maintenance on large warranty items. Southern Comfort Mechanical offers a one-time option or annual program with the Comfort Club program. For more information on furnace tune-ups and repairs, contact our heating and furnace professionals in Frisco or the surrounding areas we serve.

What are the directions to install the filter?

On the filter, there will be an arrow that should point toward the furnace as the air is being pulled from your home and through the furnace or air handler. If in doubt have an HVAC professional change it during the heating maintenance and ask them to explain if you would like to change them regularly yourself.

What do the blinking lights on furnaces mean?

Most higher-end units have status lights, the high-end units can flash like a disco. The decoding can be looked-up on youtube or a manufacturer’s site but can be hard to find. Even when the status is good the lights can look like there is something going on with green, blue, red, and yellow lights flashing in sequence.

Was this article helpful? Did it answer some of the burning questions you had about your furnace system? If so, please visit our blog section to find more HVAC-related articles, and don’t forget to contact our team for an estimate.

Our Lewisville Office:

Southern Comfort Mechanical
174 Lake Park Rd, Lewisville Texas, 75057
469-702-0701

Our Frisco Office:

Southern Comfort Mechanical of Frisco
7809 Jennifer Ln, Frisco TX, 75034
972-503-6868