It's June.  Air conditioners will be sorely tested over the next three months.  Unfortunately, not all ac's will pass the test.  Some, will invariably, fail during this time.  If your ac stops cooling, what should you do? 

As I have mentioned in previous blogs, there are a couple of things you can try before calling to schedule an ac repair.  Check and replace your furnace filter if dirty.  Also, check both the furnace and ac electrical service breakers.  Note :  Do not continue resetting a breaker that repeatedly trips as you could cause a more serious problem to your furnace or ac.  If your ac is still not cooling there is one more thing you need to do.  This is very important....TURN IT OFF and call your HVAC service provider to assist you. 

We always tell our customers to turn off an ac that is not cooling properly.   Then we set up a service appointment to diagnose and repair the ac in question.  I can't count the times that I have shown up for an ac repair appointment only to find the ac still running (or trying to).  The logic goes something like this :  "It's cooling a little bit, so I will leave it on so that I can have a little bit of cool air".  Huge mistake!  There are a couple of problems with this.  If the system is frozen or iced up (which may not be apparent), then there is nothing we can do to diagnose and correct the problem until the ice is thawed.  Which can take an additional hour or two of our time (= higher cost of repairs), or require us to reschedule the repair for another day to give the system time to thaw out naturally.  This occurs more frequently than I care for. 

Another problem occurs when an ac with a relatively simple problem is left to run which puts stress on the ac and causes a more serious failure.  A blown capacitor is one of the most common ac repairs.  The good thing is that it is relatively simple and inexpensive ac repair.  But, if the system is left running with a defective capacitor it puts stress (and creates an high temperature overload condition) on the outdoor fan motor and compressor.  Last week, I went on an ac repair appointment with this exact problem.  After replacing the capacitor, the outdoor fan motor began to operate properly, but the compressor was not coming on due to the overheat condition.  Luckily, the compressor kicked on a few hours later after it was allowed time to cool.  Another customer had the same problem last year, but was not so lucky.  They allowed the ac to run all weekend knowing that it was not cooling properly.  It also had a defective capacitor, but the compressor was damaged by allowing the ac to operate in a disfunctional state.  That customer ended up replacing their entire air conditioner system. 

So please, turn off your ac until the repairman arrives.  If you live in columbus ohio or the surrounding neighborhoods, you can call Minutemen Heating and Cooling, Inc. at Phone 614-837-5062 to set up an appointment for an ac repair for Columbus Ohio.

Thanks,

Jim Harless

Do it yourself ac repair is a bad idea.  The same goes for furnace repair, maybe even more so due to the fact that you are dealing with combustible gases and possible carbon monoxide issues.  Sorry to start with my conclusion, but I feel strongly about this.  I can't remember how many times over the last 17 years I have been called in to correct a problem that was created by someone trying to "do-it-yourself".  Or maybe they called a non-licensed person (moonlighter) to fix their ac in an effort to try and save a few bucks.  In the end, they end up paying more by having a licensed professional do it right.  I will give some examples of this. 

When I was green behind the ears (about 1 or 2 years experience), I went on a service call.  When I arrived, I found nearly all of the furnace wiring disconnected and hanging out of the furnace.  The homeowner had tried to repair the furnace himself without success.  The furnace schematics (wiring diagram) was faded and illegible.  So, I had to start from scratch and figure out how to rewire the furnace.  And, there were quite a few wires too.  It looked like a spaghetti mess lol.  I spent about 2 hours rewiring the furnace before I could even begin to diagnose the original problem.  Once I had the furnace wiring back in place, it only took a few minutes to diagnose and correct the problem.  The homeowner paid more than he would have paid if he had called in the first place instead of trying to fix it himself.

A common DIY ac repair is the thermostat.  I will admit that people have more DIY success with thermostats than other HVAC related repairs.  That said, I have gone on quite a few service calls where someone has replaced their thermostat but still had a problem.  In some cases, people assume that the cause of the ac or furnace malfunction is the thermostat when in actuality it is the furnace or ac itself.  Which means they wasted money replacing a thermostat that did not need to be replaced.  In other cases, the homeowner incorrectly installed the thermostat and created a new problem that did not exist before.  Namely, shorting out the transformer or fuse on the furnace.  And, sometimes the new thermostat itself is damaged by the incorrect wiring.  Which ends up costing more in the long run to correct.

In the summer of 2011, I went on an ac repair call.  The homeowner had paid a handyman (moonlighter) to repair his ac about a month earlier.  The moonlighter replaced the outdoor fan motor which had failed again.  During the diagnosis, I found that the motor he used was not an O.E.M. motor, but an aftermarket motor.  In some cases, an aftermarket motor can work, as long as it matches the specs of the O.E.M. motor.  O.E.M. stands for "Original Equipment Manufacturer" specifications.  But, the motor that the moonlighter installed did not match O.E.M. specs.  The capacitor size was different (not an insurmountable issue), the rotation did not match the existing fan blade (which required a new fan blade), and the biggest issue was that the O.E.M. specifications require a motor enclosure that is "totally closed", but this enclosure was "open".  The picture above is from this service call.  You can see the open enclosure.  Also, he clamped and taped the capacitor to the side of the motor instead of installing the capacitor in the control box where it belongs.  Long story short, I had to replace the motor, the dual-run capacitor, and the fan blade all with O.E.M. parts to repair this.  The home owner paid more for my repair because replacing the fan blade is usually not necessary for this type of repair plus whatever he paid the handyman to repair it the first time.

Another example illustrates the necessity of having a competent professional service your furnace and/or ac.  Several years ago, I went on a furnace repair call for a tenant property.  The landlord had a "maintenance" guy try to fix it before calling us.  I found that the furnace "flame roll-out safety" had been by-passed.  Right now, all HVAC professionals reading this are gasping!  You never, ever by-pass safety controls.  They serve a vital role.....SAFETY!  A furnace running with a by-passed "flame roll-out safety" poses a fire hazzard.  When safety controls fail, it is usually when they are detecting the condition that they are designed to prevent.  Which is the worst time to by-pass the safety control.  It is critical in this situation to get at the root cause unlying the problem.   In this case, the furnace had a defective heat exchanger causing the flame roll-out condition. 

I have many more examples, plus some I'm sure I have forgotten, but I think the point has been made.  Always hire a licensed, bonded, and insured professional to service your furnace and/or ac.  It can save you time, money, headaches, and maybe your life!

Thanks,

Jim Harless

Spring is just around the corner, and before you know it those 85+ degree days will be upon us!  Now is the time to consider servicing your air conditioner for the up coming cooling season.  Air conditioner service is the last thing most of us think about until that moment that we desperately need it.  Don't wait until the outside temperature reaches 85 or 90 degrees.  By then, you may have a hard time finding a contractor as our industry gets log-jammed during that time of the year.  Once the outside temperature reaches 70+ degrees, that's the time to call and set up an appointment to have your air conditioner serviced for the cooling season. 

Why 70+ degrees?  Outdoor air temperature has a considerable effect on air conditioner performance.  At temperatures below 60 degrees it becomes difficult to determine if the freon level is correct.  A warm outdoor temperature creates a "load" that will elevate freon pressures into the correct operating range.  So, remember to call for a spring tune-up as soon as the outdoor temperature reaches 70 degrees. 

What are the benefits of servicing your air conditioner annually?  First, servicing your ac will insure that it is operating efficiently and that you are not wasting money on electricity.   And second, some (not all) failures can be prevented by having your air conditioner serviced annually.  The things our service tech inspects include :  filters, coils for dirt build up, freon level, compressor amperage draw, fan motor amperage draw, freon superheat (or sub-cooling), indoor coil temperature drop, damaged or corroded wiring, relays for charred/pitted contacts, capacitors for proper capacitance readings, and thermostat operation.  If anything is out of spec, it can be addressed before a more serious problem arises.  Thirdly, performing annual maintenance on your air conditioner will insure its longevity. 

Here is a good example illustrating point number one :

Two years ago we picked up a new customer who had not serviced her ac in quite a while.  She signed up for our Annual Maintenance Agreement.  The previous summer (2010) she had high electric bills.  During our inspection, we found several issues with her ac.  Her ac was still running and cooling (to some degree).  But, she had a dirty filter inside, a dirty condensing coil outside, a weak dual-run capacitor (outside specs), and was about 0.5 lb low on freon.  We addressed all those issues for her.  Upon returning later that fall to inspect her furnace, she let me know how happy she was that she had the air conditioner serviced.  She said that her electric bill for the summer of 2011 was about half her electric bill the previous summer.  This is a good example of the first point. 

In conclusion, performing annual maintenance and servicing your air conditioner can pay for itself in the long run by improving efficiency, preventing failures, and increasing longevity.  So what are you waiting for?  Call us now to set up an appointment this spring for an air conditioner service inspection at phone 614-837-5062.

Thanks,

Jim Harless

Minutemen Heating & Cooling, Inc.

Hello everyone, I hope 2013 is starting out well for you!  I have some good news.  The Energy Tax Credits for installing high efficiency heating and cooling equipment that expired Dec 31, 2011 are back!  And, they are retro-active to Jan 1, 2012.  So, if you installed a new high efficiency heating and cooling system in 2012, then you may qualify for a tax credit this year.  

A gas furnace with an annual fuel utilization efficiency of 95% or higher can qualify for a credit of $150.00.  If your indoor unit has an advanced circulatory fan (a.k.a. a variable speed motor) you can qualify for an additional $50.00.  And, if your outdoor unit is 16 SEER or higher (15 SEER for heat pumps) then you may qualify for a $300.00 tax credit.

Go here for more info :

http://www.hvacdist.com/current-tax.asp

And here :

http://www.energystar.gov/index.cfm?c=tax_credits.tx_index

Jim Harless

The Dept. of Energy Rescinds Regional Standards for Residential Gas Furnaces.  A few months ago I talked about the Direct Final Rule from DOE that would require HVAC contractors in 30 northern states to install condensing gas furnaces with efficiencies at or above 90% A.F.U.E.  80% A.F.U.E. non-condensing gas furnaces would no longer be permitted to be installed.  Recently, the D.O.E. has decided to rescind that rule for the time being.  They are looking at a more reasonable revision for next year.  So, 80% A.F.U.E. non-condensing gas furnaces will still be availabe as an option for the remainder of this year.

The blog where I discussed this rule originally is titled "Furnace Efficieny".

You can find out more about this change here

https://www.acca.org/archives/news-and-media/news-room/press-releases/8232

Jim Harless

Minutemen Heating & Cooling, Inc.

Phone 614-837-5062

Why furnace maintenance is important!  Proper maintenance of your gas furnace can insure that your furnace is operating safely and efficiently.  Scheduling an annual preventative furnace maintenance inspection can also reduce the likelihood of costly breakdowns and repairs.

"Out of sight, out of mind."  "The squeaky wheel gets oiled."  These cliches come to mind when I think about the level of consideration most people give their furnace.  I have been in the HVAC trade for over 16 years now, and I know that before then, I never even thought about my heating and cooling equipment until there was a problem.  As long as it's doing it's job and not squeaking or making weird noises, it doesn't even come to mind.  But we will see why having annual preventative maintenance performed on your furnace is important. 

Taking good care of your furnace is not only good for your pocketbook, it's good for your health as well.  One of the primary concerns when performing a furnace maintenance check on your gas furnace is inspecting the condition of the furnace heat exchanger.  A crack or hole in the furnace heat exchanger can allow combustion products such as carbon monoxide to enter your home.  Carbon monoxide can cause drowsiness, headaches, and in some cases death.  I highly recommend that you have carbon monoxide detectors in your home.

For more info on carbon monoxide safety click here

http://www.safetyathome.com/home-safety/home-safety-articles/test-your-carbon-monoxide-iq-and-protect-your-loved-ones/

 The heat exchanger can be inspected in several ways.  Visual inspection with a mirror or videoscope is one way.  Also, a trained technician can tell by observing the burner operation.  Abnormal burner operation such as "flame deflection" or "flame roll-out" can be an indication that there is a crack or hole in the furnace heat exchanger.  Carbon monoxide tests can be performed on the flue gas to determine how much carbon monoxide is being produced and also on the house air stream to see if any is leaking into your home.  These are only some of the ways a technician can determine if your furnace heat exchanger is defective.  

Another potential source of carbon monoxide can be from a blocked flue.  A flue without a cap can allow birds or other animals access to the flue.  If they get in the flue, they can create a blockage that can prevent the combustion products produced by your gas furnace and/or water heater from venting properly from your home.  Also, most newer homes have a fresh air intake that replaces air lost from your home.  Appliances such as gas furnaces, gas water heaters, dryers, bath and kitchen exhaust fans all rob your home of indoor air and create a negative pressure inside which can interfere with the operation of your appliance.  Most furnaces have draft safeties and pressure sensors to prevent your furnace from operating if the flue is blocked or if the air pressure in your home is less than the outdoor air pressure. These fresh air intakes usually have a screen that filters the outdoor air that is brought back into the home.  If these screens get dirty, they can prohibit the airflow. 

A few years back, I had a customer who had an older furnace without draft safety controls.  They also had a fresh air intake to balance air pressure in their home.  Their carbon monoxide detectors were going off, so they gave us a call.  We found the flue was back-venting at the dilution air hood on the furnace creating the carbon monoxide problem.  We found the flue to be clear of blockages.  It turned out that the only problem was a clogged screen on the fresh air intake.  Once we cleaned the screen, the flue began venting properly.  Thankfully, they had carbon monoxide detectors in their home.  As you can see, there is more than one way a furnace can create a carbon monoxide problem.  One thing to take note of, all newer furnaces have draft safeties and flame-roll-out safeties that can shut your furnace down if these type of problems arise.  Also, just last year, we removed close to a dozen dead birds from a flue.  That furnace was over 20 years old, but had a draft safety which shut down the furnace due to the blockage created by the birds.  The furnace was vented into a masonry flue which did not have a flue cap.  I have a picture of the birds, but out of respect for anyone who might be eating while reading this, I decided against posting it ;)

The furnace safety controls should be checked to insure that they are operating properly.  Most furnaces have the following safety controls :  flame rectifying sensor, flame roll-out sensors, high temperature limit switch, and draft pressure and temperature sensors.

Next, we will look at furnace efficiency.  Things that can have a negative impact on the combustion efficiency of your furnace include improper gas manifold pressure, insufficient combustion air, too much combustion air, burners out of alignment, dirty burners, and a dirty manifold.  Also, a combustion analysis of the flue gas can be performed to determine if you are getting the proper efficiency from your furnace. 

Airflow can also affect the efficiency of your furnace.  Things that can affect airflow include the furnace filter, blower wheel, evaporator coil, and duct system.  In addition to visual inspection of these components, a temperature rise across the heat exchanger to determine if the furnace is operating in the correct temperature range can be an indicator of proper airflow.  If the filter, blower wheel, or evaporator coil are dirty, a higher than normal temperature rise can be expected.  If the cause of the high temperature rise is not addressed it can lead to big problems in the near future such as :  heat exchanger failure, blower motor failure, and/or high temp limit failure. 

So far we have discussed the importance of inspecting the furnace heat exchanger, burners, flue, safety controls, and airflow components.  There are some other important things to check that can be preventative in nature.  These include :  ignitor ohms, capacitor capacitance, inducer amperage, and blower amperage readings.  Measurements outside of manufacturer's specifications may indicate that now is a good time to address a potential issue.   

I could go on, but I think it is fairly obvious at this point that having annual furnace maintenance can prevent breakdowns, improve efficiency, and insure that your furnace is operating safely.

If you would like to schedule a furnace maintenance inspection, you can call us at 614-837-5062.

I hope this blog has been informative.

Thanks,

Jim Harless III

With new efficiency rules going into effect next year for gas furnaces, this is a good time to discuss furnace efficiency and how those rules will impact homeowners.

First, let's look at the differences between standard efficiency gas furnaces and high efficiency gas furnaces.

Standard efficiency gas furnaces are generally rated at or near 80% A.F.U.E. which stands for "Annual Fuel Utilization Efficiency". This means that 80% of the heat produced through combustion is used to heat your home while the remaining 20% is lost with the combustion products through the flue. The "flue" is the vent that escorts the combustion products out of your home. Those combustion products include steam (water), carbon dioxide, carbon monoxide, and various other gases. The flues for the standard efficiency gas furnaces are typically one of two types. They are "Mason" or "B-Vent". Mason flues are brick or masonry block chimneys that vent the combustion products to the roof. B-Vent flues are double-walled metal pipe that also vent the combustion products to the roof. Both "Mason" and "B-Vent" flues may be "common vented". Which means they provide venting for more than one gas appliance. Typically, you will find a furnace and water heater "common vented". 

High efficiency gas furnaces, also known as "Condensing Furnaces", generally fall between 90% and 97% A.F.U.E.  For example, if your furnace is rated at 95% A.F.U.E., then 95% of heat produced through the combustion process is used for heating your home, while only 5% is lost through the flue.  High efficiency condensing gas furnaces differ from the standard efficiency models in several ways.  The primary difference is the manner in which they are vented.  Since the heat lost through the flue of a high efficiency condensing furnace is a lot less than the heat lost through the flue on a standard efficiency furnace, the steam is much cooler on the high efficiency condensing furnaces.  So much cooler that the steam condenses into liquid water.  This is a big problem for venting into masonry or b-vent flues.  The solution is to vent the flue gases through water-tight, sealed pvc piping.  This requires a dedicated pvc flue and does not allow for a "common vent" option.  The pvc exhaust and intake (when necessary) are usually sidewall vented as shown in the picture above.  The high efficiency gas furnaces also require a condensate drain to remove the water produced by the furnace. 

 Now that we have an understanding of some of the differences between standard efficiency gas furnaces and high efficiency condensing gas furnaces, let's look at the new "Direct Final Rule" enacted by the U.S. Dept. of Energy that will be taking effect May 1, 2013.

This "Direct Final Rule" is known formally as "Residential Furnaces and Central Air Conditioners and Heat Pumps Direct Final Rule" can be found here :

http://www1.eere.energy.gov/buildings/appliance_standards/residential/residential_furnaces_cac_hp_direct_final_rule.html

 Also, you can find info on this site to bring awareness to the end consumer :

http://www.appliance-standards.org/product/furnaces

The most important impact of this rule that will affect residents of the state of Ohio and other northern states is the requirement that the minimum efficiency for new furnaces will be 90% or higher.  This means that the standard 80% efficiency furnaces will no longer be allowed to be installed after May 1, 2013. 

When I first heard of this rule, a problem immediately came to mind.  Some residences do not have an exterior wall near the furnace to pipe the sidewall vent required for the high efficiency condensing gas furnaces.  In particular, multi-family dwellings such as apartments, townhomes, and condos typically have a centrally located utility room with no access to an exterior wall for the sidewall vent.  I see this creating an additional expense to the homeowner in addition to the normally higher cost of installing a high efficiency condensing gas furnace.  The piping will need to be installed thru living rooms, kitchens, etc... and then soffitted to enclose the piping from view.  Other alternatives would involve replacing an existing standard efficiency gas furnace with an electric furnace and/or heat pump.  Personally, I would not consider that an improvement, just a way around the sidewall venting issue.  I am hoping that an ammendment to rule will be coming in the future, but I'm not holding my breath.  I'm all for conserving our energy, but feasibility must be considered.  I would think that excluding multi-family dwellings from the rule would go a long way in helping alleviate the problems that will arise from this rule.  Also, maybe a provision for certain single family homes without a good option for the sidewall venting as well.  And, then only for retrofit installations.  New builds can plan the high efficiency model furnaces into the contruction.

 There is more I could say, but I think this will suffice.

If you have an older standard efficiency furnace and have no access to an exterior wall, then now may a good time to consider installing a new standard efficiency model while there is still time left.  The last day to install a standard efficiency furnace is April 30, 2013.

In light of everything mentioned here you would think I don't like high efficiency furnaces, but not so.  I always look the high efficiency option first for my customers and give them all the of the pros and cons to allow them to make an informed and educated decision for themselves.  Usually, the only downside to the high efficiency models is the higher cost.

If you live in the central ohio area, you can call us for a free estimate to replace your existing furnace at 614-837-5062.

-Jim Harless III

It's that time of year!  Temperatures outside are dropping.  You set your thermostat to "heat" expecting your furnace to do it's job.  Only to discover hours later that the temperature in your home is dropping too.  Now what?  Well, before you call Minutemen Heating & Cooling, Inc. to assist you with this crisis, there are a couple of things you can do that may resolve the problem.  By the way, the furnace pictured here is beyond furnace repair and ready for recycling!

Safety first!  If you notice a strong odor of gas throughout your home, get everyone out.  Then, call your local fire department and your local gas service provider.  They are experts in dealing with gas leaks.  If you notice only a slight odor of gas and only near the furnace, then call us, we can help.

First of all, check the furnace air filter.  Replace or clean the filter if it is dirty. 

If your furnace is doing nothing at all, then try the following.  Check furnace breaker switch.  If it is tripped, reset it and try the heat again.  If it trips again immediately, do not try resetting it again as you could cause more damage to the furnace.  Call us to help you.  Also, even if it is not tripped, try turning it off and back on again.  Another thing, look for a switch that looks like a common light switch near the furnace.  This switch may not seem to affect any lights.  On occasion, I have gone on a service call and found that this switch had been unknowingly turned off .  It is a power switch specifically for the furnace.  Easy fix for me and a "doh!" moment for the homeowner.  Similarly, the furnace doors must be in place properly as well.  There is a safety shut off power switch that is engaged when the doors are in place.  Next, check to see if your pilot is out.  Some furnaces more than 15 years old will have a standing pilot.  This is the type of pilot that is always lit.  Only standing pilots can be re-lit.    Your furnace should have instructions on how to light the pilot.  If it does not, then you should not attempt to light it yourself.  Newer furnaces have electronic ignition systems which are self lighting and should not be lit manually.  If you still have no heat, then a furnace repair will be necessary.  

If your furnace is running, but not heating, then try the following.  Cycle the power to the furnace off and back on again.  Most furnaces have a diagnostic lock-out feature.  Cycling the power to the furnace resets this and the furnace will attempt another heating cycle.  If it still fails to heat, then call us at phone 614-837-5062 to schedule an appointment to repair your furnace.

If you have a heat pump system, and you have no heat, then you most likely have a problem with the indoor unit.  A problem with the outdoor unit may go undiscovered for some time because the indoor unit will usually switch into auxilliary heat mode when the outdoor unit fails to provide heat.  This problem will usually show up in a higher than normal electric bill (if your indoor unit is electric heat).  If this happens, check the outdoor unit.  If it is not running (give 5 minutes for delay timers), then check the breaker to the outdoor unit.  It will be a different breaker than the breaker for the furnace.  If it is tripped, reset the breaker.  If it trips again, do not reset it.  You can create a larger problem if you keep resetting it over and over again.  For example, a customer called us for a service call after repeatingly resetting his breaker.  Upon arrival, we found that a high voltage wire leading to the compressor had shifted up against a hot refrigerant line.  Over time the wire melted through and shorted against the copper refrigerant line creating a short that tripped the heat pump breaker.  Now, the initial short would have been unlikely to damage the refrigerant line.  But, the repeated resetting of the breaker burnt a hole through the copper and released all the freon from his system.  Had he called after resetting the breaker once or twice, the repair would have been a simple wire replacement.  But, in this case, we had to repair the refrigerant line and re-charge the freon as well which was definitely more costly.  Another thing to watch for with heat pumps is excessive frost build up on the outdoor unit.  By excessive, I mean 1-2 inches or more.  A light coating of frost can be normal.  The most likely causes for this excessive build up of frost is a defective defrost control or a low freon charge.  In which case, you will need to call us to set up a service call to repair your furnace or heat pump.

I hope this discussion on furnace repair has been informative and helpful.

If your furnace is still not working properly, call Minutemen Heating & Cooling, Inc. at 614-837-5062 to schedule an appointment for a service call to get your furnace repaired so that it will operate safely and efficiently  Also, we are available for after hours emergencies as well. 

-Jim Harless III

Welcome to the blog for Minutemen Heating & Cooling, Inc.  This is my first blog.  The purpose of this blog is to inform and educate consumers regarding their HVAC system.  HVAC is an acronym for Heating, Ventilation, and Air Conditioning.  In the weeks and months to come I will be discussing topics such as furnace maintenance, air conditioner maintenance, furnace repair, air conditioner repair, furnace estimates, air conditioner estimates, furnace filters, humidifiers, single stage vs multi-stage, variable speed motors, thermostats, indoor air quality, and new laws affecting the hvac industry and consumers alike.  The frequency of my blogs may vary depending on time and ideas.  The more time and ideas, the  higher the frequency of my blogs. Occasionally, I may entertain as well, but don't count on it ;)  Thanks for visiting the blog for Minutemen Heating & Cooling, Inc. 

-Jim Harless III

The typical 1” thick furnace filter usually indicates that it is good for “up to” 90 days. The key wording is “up to.” Depending on frequency of use and cleanliness of your ductwork, you may get 90 days out of your furnace filter. But, usually the filter needs to be replaced sooner than that. We recommend checking your furnace filter monthly and replacing when the filter has a noticeable layer of dirt across the surface.

This will improve the performance of your system and prevent costly breakdowns which can occur when the system is left to run with a clogged furnace filter. The filters will pay for themselves in the long run if replaced regularly.