When Azrikam the Price Is Right Heating, Air Conditioning, and Refrigeration do clean and checks

There are steps that we take for cleaning and checking a furnace.  Annual furnace maintenance is a necessary task.  It keeps the furnace in good working condition and helps it run as efficiently as possible.  Maintenance also allows a professional to find and repair minor issues before they become expensive problems.  As a homeowner, reporting irregularities that you notice to a mechanical HVAC professional also goes a long way toward keeping your home safe, lowers energy bills, and keeps your family more comfortable.  We check, inspect, repair, and maintain the whole furnace inside and out.

We clean inside the furnace

We vacuum the burners to make sure that there is nothing inside the manifold and orifice that can be blocking the gas from being distributed properly so you don't need a new furnace installation or changeout any time soon.

A lot of the time a spider makes its home inside these orifices and causing the HVAC furnace's gas not to flow through the manifolds making only 3 out of the 4 burners operational.  That can also create a delayed ignition which can be dangerous or even deadly. 

A delayed ignition is when you have 4 burners that have gas going through and 1 of the 4 furnace burners is releasing the gas very slow causing the gas not to ignite properly.  After building enough gas pressure in the heat exchange chamber it finally ignites creating a big explosion that can hurt or kill.  So the gas builds up in the furnace until—BOOM—it ignites, causing a mini-explosion.  This can harm the heat exchanger, which is a very expensive part to replace.

It is very important that you have a licensed HVAC heating company like us that can do anything in your home that has to do with cleaning and checking your furnace and other HVAC systems.

We inspect your heat exchanger looking for any signs of rust or other damages.  For years the rusting of heat exchangers has been blamed on everything from issues with contaminated combustion air to high humidity levels.  While these issues need to be controlled, they aren’t really the root cause of the rusting problem. 

When you see rust in the heat exchanger of natural draft equipment it is a sign that dangerous operation has occurred at some point in time with that piece of HVAC equipment. 

Rust is a visual indicator that flue gases are not leaving the heat exchanger of the equipment and exiting through the flue properly.  You might not think this is a big deal, but this means the combustion process is continually deteriorating while the equipment is operating.  The two main byproducts in flue gas are Carbon Dioxide (CO2) and Water Vapor (H2O).   If these components of flue gas leave the equipment properly and are replaced with Oxygen (O2) for the burner flame, the furnace is operating as it should.

When the flue gases comprised of CO2 and H2O don’t leave the equipment properly, the combustion process starts to break down inside of the equipment.  When you look at the molecular weight of CO2 it is heavier than air.  As this heavier CO2 begins to “back up” in the heat exchanger oxygen to the burner flame is slowly displaced creating a deteriorating condition.  Remember, if the flue gases don’t leave the equipment, combustion air can’t get into the equipment potentially leading to the need for major furnace repairs or even a new installation.

The water vapor side of the flue gas not leaving the equipment is the source of the rusting of the heat exchanger itself.  The two will both go hand in hand with this deteriorating condition.  The big issue is that the problem with CO2 displacing O2 is almost always overlooked.  The water vapor issue presents itself in other destructive forms as well.  It has been known to cause the rotting of collector boxes, hot surface igniter failure, and burner rusting to name a few.  You might be wondering how water vapor could do that much damage to the metal of a heat exchanger.

When you look at pH levels you will find the answer why.  If you remember from grade school science classes, pH is the scale used to determine whether a liquid is either a base, neutral, or an acid.  This scale ranges from 0 – 14. 

The neutral level for pH comes in at 7 while any number higher than this is a base.  The acidic levels of a substance will be indicated with numbers lower than 7 on the pH scale.  The lower the pH number, the more acidic it is.  The pH level of pure rain is slightly acidic coming in at 5.6 while pure water is neutral at a pH of 7.

The problem with flue gas is its pH doesn’t match either of these two values.  As the two components of flue gas interact, they create a form of carbonic acid.  Many areas and municipalities require that the condensate for condensing equipment be discharged into a condensate neutralizer for this very reason.

This acid has a pH of between 3.5 and 3.8 and is very destructive to most metal surfaces it comes into contact with for an extended period of time.  When the flue gas doesn’t leave the equipment, it eats away at any metal surfaces and eventually destroys them.  This will require a major furnace service and repair job to get your system up and running again.

The term “flame rollout” has a dangerous ring to it—especially when it's applied to your home's gas furnace.  The burner flame that generates heat inside your furnace should be contained within the safe confines of the combustion chamber.

When a furnace cannot get enough airflow, the heat exchanger overheats and suffers excess stress from expansion and contraction.  Over time, the heat stress causes cracks near weak areas such as bends or welds.  The most common cause of an overheated heat exchanger is as simple as a dirty air filter. 

Excessive soot: Soot is a problem that can occur with gas-fired and oil furnaces.  Excessive furnace soot causes the heat that the appliance produces to go up into the chimney instead of into the home.  Excessive soot also poses a fire hazard and increases the risk of carbon monoxide poisoning.  Seeing debris, soot or rust flakes in the flue vent connector or on the horizontal surfaces near the furnace is a sign that it needs any of the following: cleaning and servicing, a replacement heat exchanger, or burner adjustment.  A little oil burner soot (no more than 1/8 inch) after the furnace receives maintenance services is normal.  There is a problem, however, if the soot quickly reappears after a professional cleans it.

Irregular flame: The furnace’s pilot light should be blue, not yellow.  A yellow, faint, or irregular flame can be a sign that the burner is dirty, clogged, has a faulty ignition, a thermocouple problem, a cracked heat exchanger, or may be located in a drafty room.  A yellow flame may also indicate that there is a non-ideal balance of gases surrounding the pilot light.

Short or frequent cycling: Short cycling is when the furnace runs for a short period and turns off.  Frequent cycling may be due to bad thermostat settings, a faulty thermostat, poor airflow, an exchanger issue or a clogged filter.

Problems starting and staying on: This is an indication that you may need a new thermostat.  Such a problem might also result from bad wiring, a broken pilot light, or a broken fan motor.

Insufficient heat: When a furnace doesn’t heat a space properly, it might be the wrong size, have a clogged filter, or have a problem with the pilot light.  It is also an indication that the thermostat might be faulty.

Excessive noise: While furnaces aren’t exactly quiet, they should not make strange noises.  Noises generally mean there is an airflow problem, a clogged burner, an ignition issue, or a mechanical problem.  For example, a blower that’s always on may be the result of a faulty limit switch.

A furnace's heat exchanger is a set of tubes or coils that are looped repeatedly through the air flow inside your furnace for the purpose of heating air.  Simply put, the furnace heat exchanger is the part of your furnace that actually heats the air.  The heat exchangers in direct-combustion furnaces, typical in many residences, are not 'coils'.  They are, instead, gas-to-air heat exchangers that are typically made of stamped steel sheet metal.  The combustion products pass on one side of these heat exchangers, and air to heat on the other ,When considering the life expectancy of your furnace, you are really focusing on the life of the heat exchanger itself.  Typically a forced-air heat exchanger can be expected to last between 15 and 20 years.  Ultimately, heat exchangers fail because of the constant heating and cooling, That's why it is recommended that you replace your furnace every 15 to 20 years and have regular furnace maintenance performed to make sure your furnace lasts that long and works efficiently during that time.

Should you get a furnace replacement installation?

A good place to start is to compare your furnaces age to the national average.  The average life expectancy of furnaces in homes today is between 16 and 20 years.  If your furnace is close to this age or older, you should begin shopping.  Shopping for a replacement furnace in an emergency does not allow time to make your best decision.  Most people prefer to replace their furnace as a planned home improvement rather than a panic replacement when your furnace is faltering or failed.  For starters, look at your furnace to see if you have a pilot light.  If you do, it is almost certain to be over 25 years old!

Rising gas and electric prices are not the only reason for high bills.  Furnaces often lose their efficiency as they age especially if they have not been properly maintained.  As a result your furnace may run longer to provide the same amount of heat.  This will cause your gas & electric bills to go up.  The money you pay the gas & electric company every month could be used to pay for new furnace. 

Furnaces are like cars.  As they age, you can replace one part only to have to replace another part next year.  It doesn't take long to spend $500 just to keep the old furnace running.  Furnaces incur the most breakdowns in the last 2 years of their lives.  Another repair sign is whether you had to wait to get parts replaced.  As a furnace ages, it gets harder to get replacement parts.  This waiting can really be cold on a below zero night. 

Do you feel that some rooms are too cold while others are too hot? Or are you always trying to adjust your thermostat to make your home more comfortable? This is a sign that your furnace lacks the ability to properly distribute the air to keep you comfortable in your home. 

A yellow or flickering flame may be a sign that poisonous carbon monoxide could be created by your furnace.  Other possible signs of carbon monoxide are: Streaks of soot around furnace; Absence of an upward draft in your chimney; Excess moisture found on windows, walls, or other cold surfaces; Excessive rusting on flue pipes, other pipe connections, or appliance jacks; Small amount of water leaking from the base of the chimney, vent, or flue pipe; Rust on the portion of the vent pipe visible from the outside.

Old furnaces often start to make some strange noises as they get toward the end of their life.  Have you heard any banging, popping, rattling, or squealing noises coming from your furnace?  This could mean that you are in need of a much need furnace service or repair.  Another noise is when you hear the furnace blower running excessively.  Does your blower turn on & off frequently or does it blow cold air sometimes? If so, this is a sign that your furnace may need to be replaced Furnaces as they age run the risk of developing cracks in the heat exchanger inside your furnace.  Carbon monoxide, if present, could leak into your home undetected.  Signs of this may be frequent headaches, a burning feeling in nose or eyes, nausea, disorientation, flu-like symptoms.  Should you experience any of these, air out your house, open a window to the furnace room and immediately call a gas service technician.  Cracks in the heat exchanger can occur undetected which is why no one advises waiting until they occur.

Old furnaces often lack the ability to moisturize and clean the air in your home.  Your house air may feel stuffy or stale.  Does anyone in your family suffer from allergies to airborne dust, mold, pollen, viruses or dander? Or does anyone suffer from dry nose, dry throat, or dry skin? Other signs may be frequent dust accumulation, static shocks, drooping plants, furniture cracking and musical instruments that do not stay in tune.  These signs all suggest that your old furnace is not capable of providing you with the comfort you and your family may want or need to be safe and not sorry.

Furnace troubleshooting, servicing, and repairing

The first thing that is supposed to start when a furnace starts up is the draft inducer.  If the draft inducer does not start then you probably either have a thermostat , thermostat wiring problem, electrical problem, control board problem or a bad draft inducer.

You should use electrical black or duct tape the blower door safety switch shut and set your thermostat so it is calling for heat.  Us a volt meter set to “Volts AC” and test between terminals W usually white wire and C Com and see if you are getting 24 to 28 volts between these two terminals.  If you are getting 24 to 28 volts between the W and C terminals then your thermostat and thermostat wiring are in good shape and doing what they are supposed to be doing.  If you aren’t getting any voltage then you might have a bad thermostat, bad thermostat wiring, not getting 110 volts to the furnace make sure switch on furnace is flipped on and blower door safety switch is pushed in or a blown fuse on the control board.  Most of the time you can get these fuses at a local hardware store.  You would be surprised how many people go without heat or cooling for hours and days and all the problem they have is the switch on the side of the furnace is not turned on or the blower door is loose after they change a filter! I try to go over this with my customers before I make a service call.  If the fuse on the control board is blown this usually means that you have a short in the low voltage circuit of the furnace.  Most of the time I find that the animals have chewed through the thermostat wires and shorted them out or the thermostat wires over time have been pinched around the body of the furnace or air handler which has caused them to short out.  You will probably need to replace your thermostat wire if you find it has shorted the fuse out.  If the fuse does not fix the problem with the low voltage then you may have burnt out the transformer.

You should have a constant 24 to 28 volts AC between the R red and C com terminals on the control board no matter how the thermostat is set.  This is the power coming right off the low voltage transformer.  If you do not have 24 to 28 volts between R and C then you probably need a new transformer.  Many control boards have a fuse located on them to protect the board from getting burned up if you have a short to ground.  The fuse is usually a 3 to 5 amp fuse similar to the fuses that you might find in a car’s fuse box.  Please see picture below of the furnace control board: If you find that the control board or draft inducer is at fault we sell many different types of control boards and draft inducers.  Please send us your furnace’s model number and we will be glad to look it up and see which control board or draft inducer your furnace uses.

When we arrive on a jobsite in which a unit’s fan motor is not working or the high-limit switch has tripped, the first thing to check is power to the motor and or unit.  If there is proper voltage, check the low-voltage control circuit.  Check for proper voltage at the transformer and check for a fuse in the low-voltage circuit.  Make sure the circuit breaker is not tripped (or the fuse is not blown).  If the circuit breaker is tripped (or fuse is blown) or if the transformer is bad, it could indicate a short in the motor.  In that case, check the windings in the motor before turning the power back on.

To check the windings of a motor for an open or a short, you’ll need to measure the ohms.  If the unit has a 120V motor, it will most likely have three or four colored wires (black, red, yellow, and blue are common), a white wire, and two brown wires.  Do a resistance check between the white wire and each of the colored wires.  The higher the resistance, the lower the speed, with each color representing a different speed: i.e., four colored wires, 4-speed; three colored wires, 3-speed.

You want to see a resistance reading.  If you get a zero reading that means the motor winding is shorted and may be the cause of the tripped fuse.  If you get an infinite reading overlimit or OL on most digital meters , that indicates an open motor winding.  If either of these conditions exist you will have to replace the motor.  When checking the ohms on motor windings, many technicians have difficulty determining an open winding vs.  a shorted winding.  But it’s really not hard to tell the difference between the two.  Read the ohmmeter.  It should show a resistance.  If it shows a zero reading it probably means the windings are shorted out.  If it shows an infinite reading, that means the windings are likely broken or open. 

A good trick to remember this is that an infinite reading means the greatest resistance in the world.  It’s like an open door leading to infinity — in other words, an open winding.  Meanwhile, a zero reading means the load is taking a short cut around it — in other words, a short.  That’s just a simple trick to help you remember that a zero reading means a short, and an infinite reading means an open or broken winding.


Set your meter to volts AC, turn your furnace on so it is calling for heat.

There should be either two or three wires going into your pressure switch.

Probe one lead of the pressure with one lead of your meter while touching the other lead of your meter to ground.


Verify that all wire connections are secure from the furnace to the hot surface igniter.  Does the hot surface igniter have any visible abnormal spots on it.  Does the hot surface igniter glow when the furnace cycles.  You will need a multimeter to check the resistance of the hot surface igniter.

A hot surface igniter uses resistance just like a light bulb to glow hot in order to light the gas.  It typically has a life span of 2 to 3 years depending on the usage and the conditions of the furnace.  Set the multimeter so it can properly measure a resistance of 10 to 200 ohms.  Disconnect the hot surface igniter from the control board and measure the resistance.  A good hot surface igniter will have a resistance of 40 to 90 ohms.  Greater than 90 ohms indicates a failing or failed hot surface igniter.  If your hot surface igniter is good, then you need to verify power from the control board or ignition controller.  Disconnect the hot surface igniter and measure the voltage coming from the controller.  A good reading is 115 to 120 VAC.  If there is no voltage and the furnace is cycling for a call for heat, then the furnace control board or ignition controller needs replaced.


If there is no voltage read at the output of the transformer as read by a voltmeter, and power is available on the input side, the transformer has failed. 

As a double check, an ohmmeter can be used.  There probably will be 2 wires for the 24 volt side and 2 or more on the 120 volt side.  The color code for the 120 volt side sometimes varies but usually will have one white and one black wire.  The color code is written on the transformer(see left).  Place the probes on the wires or terminals.  The ohmmeter will read a resistance if the winding is good.  Check both windings.  Many transformers have a fuse on the 24 volt side.  If the fuse is open, the ohmmeter will read no continuity.  There is a probably a short in the 24 volt circuit.  Replacement of the transformer will not solve the problem.  The new transformer will also fail.

I recommend using a transformer without a built in fuse.  An inline fuse may be installed. 


Once this problem was recognized, the next step was the development of the electric pilot safety switch.  With this device, a thermocouple was put in the pilot flame.  The flame should cover 3/8 to 1/2-in.  of the thermocouple tip.

The thermocouple is a device made of two strips or wires of dissimilar materials.  (See photo.) They are welded together at one end; this is called the hot junction.  The pilot flame then heats the hot junction, generating a dc voltage on the other end of the two strips or wires.  This is called a thermoelectric reaction.

The output of a single thermocouple is 20 to 30 millivolts dc (1,000 millivolts = 1 V).  The voltage at the cold junction energizes an electromagnet, which closes a circuit on the electric pilot safety switch.  The way it works is, you open the “B” cock and light the pilot.  There is a button, usually red, on the pilot safety switch.  You hold it down for 30 sec, which gives the thermocouple a chance to heat up and send the necessary voltage to the electromagnet to close the circuit.  If the pilot goes out, the circuit opens.

This switch would get wired in series with the other safety and limit controls on the gas valve; nice and simple, no pilot, no main gas.  Don’t forget, back in the old days all the gas valve was, was an electric solenoid valve.

Most valves you run into now are combination gas valves.  The solenoid valve, regulator, and pilot safety are all built into one valve.  On a standing pilot model we still use a thermocouple, but in a different way.  The pilot valve is also built into the combination gas valve, so there’s no more “B” cock.

To light the pilot, you hold down the button on the gas valve to start the flow of gas to the pilot burner.  By holding the button down, you are allowing gas into the valve and, at the same time, blocking the flow of gas to the main burner outlet port while allowing it to flow to the pilot burner through a pilot tube coming from the gas valve body.  You light the pilot and hold the button down for 30 sec, and when the thermocouple sends the voltage to the gas valve, an electromagnet holds the main safety shutoff in the open position.  In this position, pilot gas will always flow and main gas will flow on a call for heat.  If the pilot goes out, no gas will flow into the valve.

The only difference between the pilot safety switch and the combination gas valve is that the pilot safety switch is shutting the gas off electrically, and the thermocouple in the gas valve is shutting the gas off mechanically.


Check your thermostat to make sure it is in the "On" position.

Stand at the thermostat while an assistant stands at the furnace.

Raise the thermostat heat settings slowly.

Turn off the breaker to your furnace.


What is a Fan Limit Switch?

A furnace has two switches called a fan limit switch and a high limit switch, these switches can be separate or in one package called a combination switch.

High limit switch

A high limit control switch will turn off the gas to a furnace if the temperature becomes top high.  For example if the blower motor stopped running then no air would move through the unit.  The flames would raise the temperature inside the unit and have no place to go getting hotter and hotter.  As a safety the high limit switch turns the gas off when the temperature becomes too high.

Fan control limit switch

The fan switch reads the temperature inside a furnace and once the temperature becomes warm enough turns the blower motor on sending warm air into a home.  This is used so that cold air is not blown in to a house waiting for the gas flames to heat up enough before the blower turns on.

 Depending on the furnace these two switches can be separate or together in what is called a combination switch.

 Some furnaces will have two or even three high limit switches wired in series and checking the temperature at deferent points in the furnace.

The first thing to check is the furnace filter.  A clogged up filter will block air flow into a furnace and raise the temperature inside it.  If the temperature inside the unit becomes to high the High limit switch will turn the gas off to the unit.  Be sure the filter is good.

 The next thing to check is if the blower motor is working or not.  If the blower motor is not working and no air is being blown through the unit it will overheat and the high limit switch will turn the gas off.

 One way to check this is go to the thermostat and turn the FAN setting from AUTO to ON.  If the blower motor blows air out the vents when manually set to ON then you know that the blower motor itself is good and something else such as the limit switch is causing the problem.  If the blower motor doesn’t turn on than that doesn’t mean the motor is bad, other components can cause a blower motor to stop working.  Before testing the limit switch power off the furnace wait a few seconds and power it back on.  Some furnaces will try a set number of times to start (Usually three) if it fails then it will have to be reset with a power off before it works again.

 Keep in mind other things can also cause this problem we are simply trying to eliminate the blower motor and filter as possible problems, as these are the most common.


Once you know the blower motor is working, and filter is clean then the limit switch will need to be tested.  There are different types of limit switches the first is the electromechanical switches that have a circular dial with a mechanical low set point and high set point that can be adjusted.  With these type of switches one side will have 120 volts for the fan and the other side will have 24 volts for the gas valve.  To test it a multimeter will have to be used to see if there is continuity when it reaches the preset temperatures on the low and high side.  Another common type is the solid-state high limit switch which is smaller an circular in design.  The solid-state switches sometimes have a reset button that should be checked for before replacing.  These also should be tested with a multimeter for continuity.  Although not recommend some service techs in the field will use a jumper wire to jumper the connections on these type of limit switches, to see if the switch has gone bad.  Don’t use a jumper switch unless you know what you are doing.  If both the blower motor and limit switch test good than other possible problems may be the contactors, circuit board, or gas valve and possibly the thermostat.


Clean your flame sensor with steel wool or emery cloth (fine sand paper).  If you have a meter that will measure micro amps then you can test the flame sensor with a multi-meter.


To understand the problems, you need to understand what draft is.  Draft is what we name the effect of how the air flows up the chimney.  It’s measured in “inches of water column.” Draft then is the combination of volume, speed, and pressure of the flue gasses.  And temperature of the gasses comes into play here as well.

For matters of this discussion, chimney draft is usually thought of as the speed at which the vented gasses travel up the stack, or pressure of the gasses.  This can also be referred to as the stack effect.  A common question might be “how strong is the stack effect?” Good draft conditions mean that the vented gasses are traveling up the chimney quickly rather than slowly or not at all.

The reason smoke (or other flue gas) goes up the chimney at all is because of the vacuum in the chimney.  The question you should ask now is “a vacuum relative to what?” The general answer is that it’s relative to the air in the house.  Don’t read too much into that because it gets tricky (for example, how does replacement air get into the house?- because the house environment is a relative vacuum to the outside.  Yet the inside of the house is not a vacuum compared to the chimney.) Let’s keep this simple and just talk about the chimney.  The pressure in the chimney is typically less than that inside the house.  Thus, the draft effect is caused by air inside the chimney being pushed up the chimney by the house air.

And why is there a difference in pressure in and out of the house, or in and out of the chimney? There can be a few reasons, but the biggest and most important reason is the temperature difference from one place to another.  Remember that when air is heated it expands? The same amount of air occupies a larger space, or you could say the same amount of space has less air (fewer molecules of air.)

The air outside the house in the winter is colder and heavier than the warmer air in the house.  It pushes its way into the house (or is it pulled, depending on how confused you want to be.) The air in the chimney just came from a fire so it’s really hot and expanded and being pushed up the chimney to the cooler air outside where warm air rises, right? That’s buoyancy.  Problems occur when these processes don’t happen correctly.

Draft is measured with a pressure meter that has a probe which goes into the smokepipe.  The meter should register a negative number, and generally speaking for residential heating appliances that number would range between -0.02 to -0.04.  Zero or a positive number means the gasses are not going up the chimney.  And too large a negative number can have its own set of consequences; but that isn’t usually the problem.  Mostly “a draft problem” means the gases are not going up the flue, this is merely a minor chimney repair.

Now there are other reasons for draft problems.  One is called Dynamic Wind Loading.  or “DWL.” DWL is caused when the wind blows on one side of the house and causes a positive pressure, and creates a corresponding negative pressure on the other side of the house.

If the windward side of the house is tight and the lee side (negative pressure side) isn’t, the vacuum resulting from the wind can suck air out of the house.  And the most likely source of that air is the chimney; it’ll pull down on the chimney, smoke and all and keep it from exiting your house! Or if a gas furnace is being vented you won’t see smoke but you still get the carbon monoxide.

The way to deal with that is to tighten up the lee side of the house and then put in an outside-air source.  There are kits for that or you can just crack a window on the windward side of the house.

The other large reason for bad draft is when chimneys have to overcome fans in the house.  Kitchen fans, bathroom fans, radon fans.  It doesn’t take much of a fan to overcome a natural draft appliance (such as a fireplace or woodstove) Again, the best answer is to allow “make up air” into the house.

The problem with that of course is that you don’t want a draft across the floor and you hate to purposefully introduce freezing cold air into the very house you’re trying to heat.  It’s a Catch 22, but I can tell you CO poisoning is a bad thing, and smoke in the house is a bad thing.  You just may have to make some choices

Finally, sometimes air actually blows down the chimney, but less frequently than you’d guess- it’s usually something else.  But maybe your chimney is short and next to a larger part of the house or a bigger building.  The same problem occurs if your house is located at the base of a mountain.  If you have this problem, a Vacustack is a good solution if you can’t raise the chimney to the proper height.


There are good reasons for changing your furnace filters on a regular basis.  If you do not change them regularly, you may be losing some of the protection that they provide.  Filters can become full of dust and other particles and then they will not trap the new particles that come through.  This means they will be released into the air and you will be breathing them in.  In addition, your furnace will have to run harder and will be less energy efficient if your filter is dirty.  So how do you know when to change that filter? Here are some general guidelines that can help you determine how often is best for you.

Animals are one thing that will affect when your filter needs to be changed.  If you have multiple animals then you will change your furnace filters more often than if you have none.  Generally those with multiple animals will change a one or two inch filter every month.  A four inch filter will need to be changed every two months and a five inch filter every three months.  If you only have one animals then you can change that and change the filters every two, four and six months depending on the size of your filter.  No animals means you can change every three, six and twelve months.

Dust is another thing that can affect the performance of your filter.  If you get a lot of dust in your home then you will want to change more often.  For one and two inch filters you need to change once a month.  Four inch filters can go two months and five inch filters can go three.  Moderate dust will change those numbers to two, four and six.  If you have no dust and no other factors then you change your filter every three, six or twelve month depending on the thickness.

If you always have it on then you will want to change your one and two inch filters monthly.  If you sometimes have it on, they can be changed every couple of months.  If it is never on you can wait three months.  Four inch filters will be changed every two, four or six months depending on whether the fan is on constantly, sometimes or rarely.  Five inch filters will be three, six and twelve months

Smoke can be detrimental to the filter and will make you have to change it sooner.  Multiple smokers mean that one to two inch furnace filters should be changed monthly, four inch filters every two months and five inch filters every three months.  One smoker changes those numbers to two, four and six.  If there are no smokers then filters can be changed every three, six or twelve months based on the thickness of the filter.

Since this lets a lot of dust and dirt inside, it can impact how often a filter should be changed.  If the doors and windows are open a lot, change those one and two inch filters monthly.  Change four inch filters every two months and five inch filters every three months.  If you only keep them open sometimes then you can change every two, four and six months.  If you never have them open then you change filters at three, six and twelve months based on your thickness.

When you change your filter is based on more than simply your filter.  While the thickness plays a prominent role, so do the factors in your home.  Quality Furnace Filters provides high quality replacement filters with top MERV ratings so that you get the best results in both air quality and energy efficiency.