Did you know that clogged air filters are the primary cause of heating and cooling system problems? Dust and debris in a home air filter restrict air flow, which forces your furnace to strain and use more energy to heat or cool your home. Just like replacing your car engine’s oil and air filter every 3,000 miles, a clean HVAC air filter protects your furnace system from becoming damaged and, ultimately, failing entirely. But how can such a simple and relatively inexpensive component have such a big impact on energy consumption, equipment life and air quality? In other words, how can a $15-30 filter protect a $2,500-$3,500 heating and cooling system? To answer this question, we first need to understand how your home is heated and cooled and then how air filter clogs prevent your system from operating efficiently. A forced-air system, which is the most common heating and cooling system, uses a heat exchange to heat or cool incoming air that is then blown through metal/flexible ducts to the various rooms in your home.

As the warmed or cooled air flows into the rooms, the unit’s fan pulls existing air out of the rooms via a separate set of “return” ducts and toward the heat exchange (where it is again heated or cooled). 6 ton air conditioner unitThis circular cycle continues until the desired temperature is reached.how much should a 4 ton ac unit cost Here’s a good guide on how often you should change your air filter.booster for ac unit When your air filter is clogged, your air handler must work harder to compensate for the blockage of air flow. In addition to driving up your utility bill, the reduced air flow through your heating and cooling system can cause your heat exchanger to overheat and shut off too quickly, preventing your house from warming up.

If that happens too often, the electronic "limit switch" safeguard can fail, and then the furnace won't fire up at all. This service call and new part can easily cost you $175. So what’s the big deal? Does an air filter really matter?  In an effort to answer this, let’s take a look at what happens if you do not routinely change your heating and cooling filter.  Here are some clogged furnace filter symptoms: Because the system relies on the constant recirculation of air, the performance of your heating and cooling system’s blower fan can have a big impact on your home’s energy consumption. The harder this fan has to work to draw air throughout your home, the higher your energy bills will be. In fact, a clogged filter can use 15% more energy, according to the Department of Energy. This inefficiency increases quickly as the filter becomes more and more clogged, or until the filter is serviced. If your air filter clogs during the summer cooling season, this can cause the evaporator or cooling coil to freeze up because not enough air is moving past the coil to dissipate the condensation that is normally produced during the cooling process.

Lack of adequate airflow causes this condensation to freeze – reducing the unit’s ability to remove heat from the air (e.g., cool your home) and, most likely, eventually causing your air conditioner to break down. Blower fans push the air through the filter. If the filter becomes too clogged with dust, dander and debris,then the blower has to strain harder to pass the air through a clogged filter. With reduced airflow you can experience hot and cold spots in your home, and it can be difficult to reach your desired indoor temperature levels. With less air flowing through the system due to the clog, the central air conditioning and heating system will run longer in an effort to heat the home, raising energy usage. In fact, according to a study by the Florida Public Service Commission, the number two cause of high energy bills in the summer was a clogged air filter. A clogged air filter will allow all that dust and debris that should be filtered out to be re-circulated back into your home.

This can cause chronic allergies and especially be dangerous for people with asthma or other respiratory conditions. If you own pets or keep many chemicals around the house, the indoor air quality will be even worse with a clogged filter. You might not notice a sniffle here or there, but over time, poor indoor air quality will impact your health in a very negative way. Can a clogged air filter cause a heater to stop?  The answer is yes, and likely the costliest result of an improperly changed air filter may be the internal damage it deals to your central air conditioning and heating system. According to the Diamond Certified Organization, a clogged furnace air filter is the primary cause of equipment failure. Essentially, that overworked air blower discussed above may give out entirely, causing the whole system to fail, an outcome that can cost thousands of dollars to repair! Here’s a good guide to know how to change your home air filter. Check out how valuable clean air filters are for your home:

When you think how much can go wrong when you have clogged air filters, you take to heart the benefit that an air filter clog detector offers. Our thermostat died yesterday, but after replacing the dead batteries with fresh batteries, and confirming the LCD screen was operable, our AC no longer turns on. I have attempted a factory reset on the thermostat, and I do hear a quiet but definitive "click" when I believe it is attempting to activate the HVAC unit, but that's as far as it gets. One theory I have is that the batteries were long dead, and the thermostat was getting it's power from the wiring directly, which means it could be the HVAC unit that died. However, it's one of the first times I've had to deal with a HVAC unit personally, so I'm guessing. I reset the breaker a couple times to see if that would do it, but it's a no go (it is clearly marked on my panel with a aluminum bridge between both breakers). Anything else I can try before I call a pro? Sounds like you may not have power from the transformer.

You can check this using a multimeter, by testing the voltage between the red R wire and the blue C wire. You should read somewhere around 24VAC, though depending on the system it could be anywhere from about 6VAC to 30VAC. Most thermostats only use the batteries to power the thermostat itself, LED display, programming, date/time, etc. Thermostats with a C wire (like yours seems to have), sometimes only use the batteries to remember your settings during a power outage. The actual power for signalling heat/cool, is supplied by a transformer in the furnace itself (the red R wire). If there is no power on the R wire, the thermostat has no way to call for heat/cool. In this case you'll have to have an HVAC tech troubleshoot, and possibly replace the transformer. You could use your multimeter to verify the furnace itself is getting power, though this is slightly more dangerous since you'll have to open the service panel on the furnace. This could put you in danger of electrocution, and should be avoided if you are not familiar with HVAC systems.

The only other thing I can think for you to check, is to look for a serviceman switch and make sure it's in the ON position. A serviceman switch is a switch on the feed line to the furnace, that allows servicemen to turn the power off to the furnace to service it. It should be located very close to the furnace, and within line of site of the furnaces service panel. If there is line of sight from the furnace service panel to the breaker panel that feed the furnace; or this is an old installation, you may not have a serviceman's switch. Your best bet, is to simply call in an HVAC technician to service the furnace. So I had the same issue and called my buddy who is a certified HVAC technician and he helped me trouble shoot the problem. First he had me check to make sure all the wires were secure behind the thermostat, but they were secure. Then he had me take off the panel on the heater/AC Unit and push in the door trigger to see if there were lights. There were lights, which meant that power was going to the unit, just not making it to the thermostat.

Then he had me check a fuse on the main circuit board that had the number 3 on it. The fuse was not blown. Next he asked me to check the AC condensation overflow pipe to make sure that there wasn't a clog because if there is a clog the safety valve will cut off power to the thermostat. Sure enough, this was the issue. There was a 1 inch PVC pipe running up along the left out-side of my AC/heater that went down into a water pump that was clogged. I simply unclogged it and the AC cut on immediately. I just had this exact issue. I called the HVAC emergency service number and the technician called me back. He advised to unscrew the bottom of the kill switch or float. There is a yellow wire that leads to it. Once I drained all the water ,the system turned on instantly. My A/C stopped working because the batteries in my (Honeywell) thermostat needed to be replaced. I replaced them and plugged it back in the wall mount. The A/C still did not work, but the LCD lights were on. I had to remove the face plate and replug it back into the mount.

This time I pressed the center of the LCD screen and got it fully connected which turned on the A/C unit. Make sure you put the batteries in right. Don't let the springs fool you like they did me. I put both batteries in with the - (minus) sides on the springs. Put one battery with the + side on the spring. It should show you the + signs on the battery holder. Before anything, try reset button at the furnace itself hidden behind the cover. It's one of those that activates when the cover is on and deactivates when the cover is off. My problem was exactly that. I put brand new Panasonic batteries in my thermostat and it did nothing. However, it worked with the old batteries, one of which was Energizer, and the other was Duracell. Clearly it takes a stronger battery.I didn't read all the responses, but thought this would help. If your thermostat has a R and Rc, then there has to be a physical wire (jumper) connecting the R and Rc, along with the red wire going into the R slot.