Saturday, 16 December 2017
Don’t Throw Away Your Old Thermostat!

You’ve probably heard us talk about the benefits of using a programmable thermostat, or have read our head-to-head comparisons of the Nest and Honeywell smart thermostats.  We’ve touted that swapping out your thermostat can be a do-it-yourself project, but, any time you replace a thermostat, you’re left with what to do with the old one. 



what should I doYour first inclination is to place it in the trash – especially if the reason you’re replacing it is that it no longer functions.  STOP!  Did you know that thermostats contain hazardous mercury that can contaminate the environment and can be fatal?  While installing a new smart thermostat helps protect the environment, throwing your old thermostat in the trash does just the opposite!

Since the 1830’s, thermostats have contained mercury – a metal that is liquid at room temperature and gives off vapor if not contained.  The new electronic thermostats do not contain mercury.  Although mercury thermostats are the largest source of mercury in homes, other sources of mercury include CFL and fluorescent light bulbs, batteries, and thermometers.  But there is no concern with exposure to mercury inside these devices, as long as the mercury is contained.  The problem arises when you throw them into the trash: the trash goes through a compactor, and then is taken to a landfill, so it is likely that the mercury bulb within the thermostat will bust at some point, and the mercury will escape.  Mercury does not break down.  It gets into the ground water, our lakes and streams, fish and birds, and becomes concentrated in our food supply, and in people.

Mercury contamination, Health Hazards of Mercury, Toxic mercuryAccording to the World Health Organization, mercury exposure is a major public health concern.  It can result in neurological and behavioral issues, kidney toxicity, and digestive tract and lung issues.  In utero and in children, it affects development, language, memory, cognitive thinking, motor and spatial skills, and attention.  It can be fatal if inhaled or ingested.  

mercury recycling, mercury in trash, banned thermostatsMany states have already taken steps to ban mercury-containing thermostats from being sold or installed.  In most states, including TN, it is illegal to throw out thermostats in the trash.  Although mercury cannot be destroyed, it can be recycled and reused.  However, mercury-containing products cannot be recycled by simply throwing it in your curbside recycling container.  So, what should you do?

Place your old thermostat in a sealable container such as a ziplock bag or plastic tuperware container.  This is so that if the mercury bulb breaks inside the device, its vapors will not be breathed in.

Check online for the nearest hazardous materials drop-off site.

thermostat installation, thermostat recycling But the easiest thing to do is to give it to us or any HVAC contractor.  We are all obligated to recycle the thermostats for you.

So, next time you’re getting your Spring or Fall maintenance visit, give us your old thermostat.  Or better yet, call on us to install a new thermostat for you, and we’ll take your old one with us when we leave.

If you live in the Nashville and surrounding area, call on us at 615-832-8500. We’re here for all your heating and cooling needs.

Posted on 12/16/2017 8:04 AM by cherylaustin
Friday, 1 December 2017
Worst Heating Advice: The 7 “Deadly Sins”

podcast, audio, heating adviceHere is a sample of some of the worst advice we’ve heard over the years when it comes to heating your home. These mistakes may cost you money, damage your system, or sacrifice your comfort.

  1. air filtersAir Filters:  Some folks buy the higher quality air filters – like the ones that filter allergens – and then mistakenly think that since they are higher quality, they won’t need to be changed as often. All air filters need to be changed at a minimum every 3 months to avoid damage to your air handling system. Actually, a case can be made that the higher quality air filters may need to be changed more frequently, since they trap more particles and are apt to get clogged up sooner!
  2. Vacationing:  Many folks try to save money by turning their heat off when they’re going to be away for an extended time. But if temperatures drop below freezing, your pipes could burst causing costly repairs!  Instead, turn the heat down to no lower than about 55 degrees. In fact, it's a good idea to turn off the water to the house (via the main cutoff valve), and then open up all the faucets so there is no possibility of frozen pipes. That's because if the power goes out while you're gone, the heat won't work anyway.
  3. Sacrificing efficiency: Many folks will crank up the thermostat to keep warm. But by making your system work harder than it has to, you’re decreasing its lifespan, which will leave you without heat sooner. Take advantage of ways to increase your heating efficiency like reversing your ceiling fans, opening drapes during the daytime and closing them at night, using a programmable thermostat, unblocking air vents, adding attic insulation, and sealing up air leaks. This will make you feel warmer without having to raise the thermostat as much.
  4. Closing off unused rooms: This is a mistake many homeowners make which only causes more stress to your system. Unless you intend to completely seal the unused rooms (including the air gap under the door) and the return air grille is not located in or near that room, a better solution would be to create a separate zone for that room (see: Is Zone Control for Your HVAC the Answer?).
  5. Using a fireplace or other local heat source to supplement your HVAC system:  Some people think that it will help keep their house warmer if they use their fireplace in addition to their HVAC system. However, the fireplace causes already warmed room air to be sucked up the chimney and creates drafting which actually makes the house colder and makes your HVAC system work harder. Running exhaust fans for an extended period of time has a similar effect.  Furthermore, using the fireplace greatly increases indoor air pollution (particulate, soot, and toxic chemicals in the air, which can trigger allergies). Using space heaters, candles, or kerosene lamps to supplement your central HVAC system also carries the added risk of house fires.
  6. Covering your outdoor unit to protect it from rain and snow:  While the unit is on and operational, it must have good air flow all around it in order for it to operate, and you will damage the unit if you operate it with the cover on. You’ll need to keep the fall leaves off the unit, too!  The only time it may be covered is if it's turned completely off at the circuit breaker. Keep in mind, a covered unit makes the perfect living space for small critters that can gnaw at your wiring and insulation, and it’s also a perfect environment for mold to accumulate.
  7. Skipping maintenance visits:  Annual service is cheap compared to the cost of a breakdown. Having preventive maintenance will keep your system running at peak performance and efficiency (thus keeping you warmer), and will prevent future problems (thus saving you money). Plus, it could detect a potential health hazard, such as a carbon monoxide leak (see our posts Deadly Carbon Monoxide from Cracked Heat Exchangers  and Your Furnace Can Kill You!). Don’t just ignore danger signs like unusual smells or noises – call a professional!  

If you live in the Nashville and surrounding area, call on Interstate AC Service for all your heating needs, at 615-832-8500. We want to help keep you warm and safe this winter! 

Posted on 12/01/2017 7:00 AM by cherylaustin

Important Tips & Advice



You often don't think about your heating or air-conditioning system until something goes wrong. But there is so much you can do to help keep your system from breaking down. We regularly post information to help you learn what you can do to keep your system running, to save money and energy.  Search our many posts, videos, and podcasts, for valuable information that is never a sales pitch. Subscribe to receive an email when something new is posted, so you won’t miss any important tips.

Choosing a Repair Company

Whether you’re talking about heating or cooling, repairing or replacing a system, you want a company that can advise you reliably based on what is in your best interest, not based on what is convenient or what earns them the most money (commissions). We'll help you choose the best solution to fit your needs. Check out our many posts at HVAC News You Can Use and our podcasts.

Going Green

We're concerned about the environment and know all the latest technologies - such as geothermal systems, LED lights, and smart thermostats - that can reduce energy and put more "green" in your pocket!  We've provided HVAC systems in certified LEED buildings and written many posts on ways to Go Green.

The Sign of Service

We are a repair company performing a full range of commercial and residential heating, air conditioning, energy management and comfort products service, maintenance, and installation. We are a locally-owned company serving Nashville-Davidson County and the surrounding counties including Williamson, Rutherford, Wilson, Sumner, Robertson, and Cheatham.

Who We Are

Our service technicians are fully trained and experienced.  We can tackle the most complicated system to the simplest of systems – from large commercial plants to single-family homes.  Our ownership group of Eddie Hutton, Tony Anderson, Roger Eldridge,  Swaney Powers and Alan Seilbeck have over 125 years combined experience as leaders in the HVAC industry.


We are proud of our dispatchers that respond to your telephone call. When your system is down they make things happen. Our trucks are loaded with most parts needed for a quick repair. You can call day and night 7 days a week. Our normal weekday hours are 7:00AM to 5:00PM. Click on the button below to schedule a service call online. Emails and forms can only be answered weekdays from 7-5.”  

615-832-8500 Online Service Call


Did you know you should service your HVAC on a regular schedule – just like you would your car?  We have specialized maintenance programs to ensure the clean, energy efficient and safe operation of your HVAC systems.  This helps minimize service interruptions/breakdowns and maximize your equipment's lifespan.  All maintenance contract customers are assigned a primary technician that will get to know your facility and equipment and will treat it like his own.  You’ll receive discounts on repairs or new installations, and get priority service when it is cold or hot outside and you need service promptly.  Plus, maintenance contract customers are never charged overtime rates for emergency services after-hours, weekends or holidays. We’ll teach you how to save on maintenance costs by showing you things you can do yourself and when you need a technician. Here are some good posts:  Repair vs. Replace, Things to Try Before Calling for Service, Springtime Tips that Pay Off.


Our team takes on HVAC projects for office, school, retail and industrial facilities. Check out these case studies:

Replacement of a 250-ton Cooling Tower

Ductless HVAC at Brentwood Middle School