Fixing Common Thermostat Problems

Most homeowners have little HVAC knowledge beyond using the thermostat. If your thermostat fails, many people end up calling a Denver HVAC company thinking there is something wrong with their air conditioning equipment when in reality, there is something wrong with the thermostat. When the AC refuses to turn on, it can be hard for someone who is not an HVAC expert to determine if the problem is in the equipment or in the thermostat.

However, before you call a Denver HVAC company, try and follow this troubleshooting guide to see if you can get to the root of the problem. Even more advanced digital and zone-control thermostats really just function as thermometers that switch the HVAC system on and off depending on the temperature. As an electronic switch, the thermostat needs to be hooked up to power in order for it to work and communicate with the heating and air conditioning equipment.

Usually the power for the thermostat comes from the air conditioning unit itself. So any break along this line could cause the thermostat to turn off. You can check the circuit breaker in the air handler or heating split system to see if it has flipped off. Sometimes the handling unit also has a power switch outside the unit that looks like a light switch. Some digital thermostats have two different power sources: battery and wired from the external unit. The batteries power the display, so if the batteries go out, the display stops working but the ac unit does not stop cooling. You can save yourself a lot on calling a Denver air conditioning repair company by simply replacing the batteries. The batteries are there to maintain your programmed thermostat settings in case the power goes out.

If the problem with the thermostat is not the power, it could be the location the thermostat is installed. Except in very advanced models with multiple temperature sensors over the building, most thermostats have the thermometer built in. That means if the thermostat was built into an area that does not represent the air temperature in your home then it will give false readings.

Thermostats with mercury bulbs need to be level to give accurate temperature readings. Heating anticipatory can also get out of whack when not properly calibrated. The anticipatory needs an amp meter in mechanical thermostats to adjust to make sure it properly keeps the blower running past the burner time to get excess hot air out of the ducts.

Air Conditioner Condensing Unit

The air conditioner condensing unit is one half of the cooling cycle with the evaporator coil. The condensing unit's job is to diffuse and reject heat, while the evaporator coil absorbs heat. All HVAC technicians learn this as the first step in their cooling education. The condenser is located in the big boxy exterior unit at most buildings. Heat pumps also use condensers, but most people North of Denver do not use heat pumps because the efficiency of heat pumps decreases as the temperature drops.

The condenser along with the compressor is the main transferor of heat between the outside air and the air blowing through your house. To do this, the compressor must be sealed inside the cooling cycle, and that is why compressor replacements are so common. It is very hard to try and repair something that is sealed within the system. On the other hand, there are many things you can do to try and maintain the life of your condensing unit. If not properly maintained, the condenser and most other air conditioning parts will go into a downward spiral before they self destruct. As the parts become worn and less efficient, the compressor and blower motor will start working harder to try and keep cooling despite reduced ability. Eventually parts overheat and fail.

One thing you can do to maintain your Denver HVAC system to to check the outside cooling unit before summer starts and it is in heavy use. I recommend calling a Denver air conditioner company to perform the check, but if you feel handy and know how to operate around electricity, then go ahead. The first step before doing any work on a condensing unit is to shut of the breaker supplying electricity to the unit. Spin the fan and see if it turns. Then turn on the power and switch on the thermostat and make sure the fan starts blowing upward a good deal. A common problem with these condenser motors is bearing failure, which will stop the fan from spinning properly.

The main reason you want to check the condenser fan motor before you operate the system is because it is connected to the compressor. A failure at the fan can overload the compressor, and the compressor is a much more expensive part than the condenser motor.

Just like evaporator coils, condenser coils can build up dirt and gunk which will decrease efficiency. Just like everything else in central air, as efficiency goes down, the system tries to work harder to compensate until it fails. The solution is to call an air conditioning services Denver company to clean the condenser coils. You can also do it yourself, but you will need to turn the thermostat and breaker off and pull the plug on the condenser electrical box. You will need to spray the condenser with enough pressure to remove dirt without bending the fins. A little soap can help too. The key to maintaining performance with these units is maximizing airflow. So the condenser should be clean and the exterior unit should have clear airflow.

Filter Role in Maintaining HVAC Performance

Many homeowners with central heat are unaware that they even need a filter for their HVAC system. The filter cleans the air for two primary reasons: to keep you healthy, and to keep your heating and air conditioning equipment healthy.

For your central air system to work properly, air should easily circulate through the ducts, vents and evaporator coils. All of these parts can become clogged by dirt and other foreign particulate matter. Clogged air works means the compressor and blower have to work harder to push air through the system. They will heat up and eventually work at high energy, sub-optimal cooling modes, then fail. Dust inside the evaporator clings to the moist coils and stops the heat transfer between he air and coil coolant. You can get a recommendation for a good quality HVAC filter from your local Denver air conditioning service company. A poor quality filter will not strain out enough particulate matter to be effective.

These quality air filters also make a big difference on the quality of air you breath in your home. Your filter should stop pollen, dirt, harmful chemicals and allergens from being circulated though your home's Denver HVAC system. Along with the traditional physical filters you can also get electronic air cleaners and electrostatic filters. These offer much more filtering ability and do not need to be regularly replaced.

The electric charge on an electrostatic filter pulls dust to it out of the air. The dust is attracted from a distance, instead of having to get caught up in a tangle of webbing like a traditional filter. A HEPA (high efficiency particulate air) filter is the Denver heating professional's choice when it comes to air filtration. These filters are certified by the Department of Energy as being very effective at removing small airborne particles.

The first filters were created for work on the atomic bomb to stop the spread of radioactive particles. HEPA filters are well used in hospitals and research labs, these filters will stop most airborne viruses, mold and bacteria. Hospital filters may include a ultraviolet light to kill all organisms in the air. Airlines used to be a prime location for the transmission of disease untill HEPA filters were installed. Now airline cabins have lower dangerous organism rates than the average home. Residential HEPA filters are also available and you HVAC company would be happy to help you install one.

Heating Your Home With Solar Energy

One of the cheapest, most environmentally friendly, and efficient ways to heat water is to use solar water heating. A new advance in the HVAC community is solar energy for heating homes. Even in the winter, the sun still bathes the earth with an incredible amount of free energy. The main limitation for solar heating is the climate. In cloudy areas like London, solar heating my not be the best choice. However HVAC in Denver is a great place for home solar energy because of the nearly year round appearance of the sun.

Solar heating is divided into active and passive systems. Passive systems use architecture and smart building design to allow the sun to heat a building. This is not the place for Denver heating companies because passive heating does not use any mechanical equipment.

Active heating collects either heat or solar energy in the form of electricity to heat a house. Then pumps or a HVAC system pushes the heat around the house from the stored heat source. A simple device that can heat a whole house is the non-concentrating flat plate collector. These collectors use a simple plate of some sort of heat-conductive material like metal to absorb solar heat which is then pumped through the house. If your furnace is broken, instead of calling your Denver furnace repair company, consider installing a flat panel solar heat collector. These devices are actually cheap and simple. Not only will you be saving the environment through reduced energy use, but the Denver heating devices pay for themselves after several years of service.

A little more advanced design is the concentrating collector, which uses mirrors or some other device to concentrate all the solar energy to heat a smaller absorbing area. The final and most technically advanced design is using photovoltaic cells to convert solar energy into electrical energy. These systems can be integrated into your house's whole power supply, so it will supply you with electricity for uses other than HVAC.

These solar cells are becoming increasingly efficient and user friendly. A common design has the cells hooked up to batteries to continue to provide power even when the sun is not out. Solar cells create DC current which must be converted to AC to run appliances in the western hemisphere. Any heating device worth the price should be able to continue providing heat at night and on overcast days. Otherwise, you can just use your solar heating device as a supplement, to reduce your energy bills on sunny days.

How TXV thermostats work

If you are smart and want to save money, you have a programmable thermostat; a thermostat that monitors air temperature and controls heating and cooling digitally. Most Americans however, have an old fashioned thermostat with a wire thermostatic expansion valve. If your thermostat is round or square and says "Honeywell" you are in the same boat with most Americans with their wire thermostatic heating controls.

These thermostats work by monitoring the size of a coiled length of wire. As the temperature increases, the wire expands, and as it decreases, it contracts. Although not the most accurate, these thermostats have been a staple of Denver HVAC for over 50 years. Inside the actual cooling apparatus, there is another kind of thermostat that regulates the equipment. This is a thermostatic expansion valve, or TXV.

Instead of measuring the ambient air temperature, the expansion valve controls the refrigerant as it flows into, and boils out of the evaporator. This split separates the high and low pressure sides of the system. Although still mechanical, the TXV is a little more complex than the Honeywell on the wall, because it must balance three different forces: the bulb pressure trying to open the valve, the spring pressure which tries to keep it closed, and the evaporator pressure, which also forces the valve closed.

All certified Denver air conditioning services technicians learn these forces early on in their HVAC training. With the advent of central air conditioning and heat pumps, many thermostats ore more complex. However the simple thermostatic expansion valve will close if evaporator pressure increases and bulb pressure is stable, and will open if the bulb pressure increases.

Superheat is a Denver air conditioning term that refers to gaseous refrigerant that is still maintaining excess heat. This increases pressure on the bulb, which opens the valve to allow more refrigerant into the evaporator. A problem with your TXV will send your air conditioning out of line because the pressure differential essential to the cooling cycle cannot be maintained if the valve is stuck open or closed. A Denver HVAC technician can identify problems like this relatively quickly. The thermostats come from the factory already calibrated, but the settings may not match your local air conditioner use profile very well.

EPA Standards for HVAC Equipment

The majority of the US is in a temperate climate. This means that although the temperature does not reach extremes found in tropical and arctic latitudes, there are major seasonal weather variations. Most Americans choose to use a central air or HVAC system to control interior temperature. For large HVAC jobs like schools and warehouses, the cost of ventilation means that careful planning must go into designing the systems. Average temperatures, energy savings, humidity, local and national codes and indoor air quality are just some of the factors that most be considered on public works projects.

The first step for a large building is using central air handling units, instead of individual ventilators in each room. In some instances like a isolated field house, a unit air conditioner may be a better choice because they take up less floor or roof space. Individual units are harder to maintain in a group and cause other ventilation and moisture problems when combined with a central unit. Central heating is especially popular with teachers because it is quieter and therefore they do not mind using it in the classroom. Denver air conditioning companies installed central heat in Denver high schools over 30 years ago and the system has been a success. Central heat is less prone to drafts because of multiple sources of air. A professional HVAC company can maintain a central unit and tweak the global settings to control humidity.

The consolidated design of central units allow them to be serviced without disturbing the work in a building- and they generally take up less interior space. To meet EPA certification for government buildings, HVAC systems must meet certain requirements. Coils must have sloped non corrosive drain pans to prevent water from stagnating or rusting the system interior. They should be in a wall cabinet with easy access that also reduces sound. This means double wall replacement doors with tight seals. EPA filters are always at least two inches thick. A well designed filter bank will take these high performance filters over a large area for max lifetime. Air filter monitors notify Denver HVAC techs when to replace the filters, as well as any major problems in the system.

To maintain indoor air quality, the easiest solution is to increase air flow from outside. This must be balanced with cost, because to increase air flow, your HVAC system must run longer. The minimum government standard devised by www.ashrae.org is 15 cubic feet/min of airflow per person in schools. Many systems just meet this standard for minimum cost. Energy recovery equipment can minimize the cost from increased ventilation airflow. Energy recovery is popular in Air conditioning in Denver and the east because the technology in this option saves money on large scale HVAC systems.

HVAC FAQ

Air conditioners are measured in "tons." A 1-ton HVAC system is the equivalent of 12,000 BTU/H. Depending on the spatial layout of your home and the insulation quality of the house, you can expect every ton to cool between 300 and 800 square feet of space. Although tonnage estimates are good for initial pricing and product research, the only way to know for sure if the system is a good size is to have the home professionally evaluated by a Denver HVAC technician.

"Does an Air Conditioner's "SEER" Value Matter?

SEER stands for "Seasonal Energy Efficiency Rating." Although some air conditioners have simple EER values, seasonal values are more accurate because they measure how efficiently a cooling system will operate over an entire season according to Energy Star, a service of the EPA and U.S. Department of Energy. SEER values are important because a more efficient air conditioner will waste less energy over time, leading to decreased electricity bills. When comparing central air conditioning units, look for a SEER rating of at least 15.

Is Central Heating better than installing a heat pump?

In terms of efficiency, water transfers energy at a much higher rate than air although radiant heat has been found to be more comfortable for the human body than warm air heating from a heat pump. A weak heat pump will generally only heat one room, using fan forced air, where as a central heating system can heat the whole house with a radiator system.

Why Have Your Air Ducts Professionally Cleaned?

Contaminants in your Heating Ventilation Air Conditioning (HVAC) system can aggravate asthma and allergies. Duct Cleaning can help eliminate bacteria and fungus to improve the air quality in your home. Cleaning your air ducts can protect everyone in your home from breathing contaminated air. Cleaning your air duct system can help maintain a cleaner home, requiring less dusting. Cleaning your air duct system helps your HVAC system run more efficiently, resulting in less run time and lower heating and cooling bills. Cleaning your air duct system can also extend equipment life. You should consider having your ducts cleaned if there is substantial visible mold growth or any other physical contaminants inside sheet metal ductwork or on other components of your heating and cooling system.

What should I do if my Pilot Light goes out?

Pilot lights do go out occasionally. Some people even shut them off in the summer. Every homeowner should know how to light his or her pilot so you do not have to call a Denver HVAC technician. It isn't too difficult and there are usually instructions printed on the equipment itself. Many of today's systems don't have a pilot light, they use spark or electronic ignition. Always follow the instructions on the appliance before anything else. Turn off furnace, boiler, or water heater at thermostat or power switch. Locate the gas valve and turn knob to "pilot" position. Hold down the red button, which sends gas to the pilot burner.At the same time hold match to pilot burner. Continue holding button for 60 seconds. Now let go of button, pilot should stay lit. If not, you need to call for service. Turn gas valve knob back to the "on" position.Turn on appliance, turn up thermostat, main gas should light. Remember to put back metal cover if your system had one. If your pilot light goes out more than once a season there could be a problem.
How often should I change my air filters?
For best performance of your system your air filters should be changed every three months although this depends on the conditions in your home. If you have to dust your furniture once a week then you should stick to the quarterly filter changes. You can tell when to change an air filter by inspecting the back side of the filter, any dirt or discoloration on the back side indicates the filter is fully loaded and is releasing dirt into the air stream.
Will a programmable thermostat really save me money?
Generally, as with anything, this depends on how it is used. The more you set the thermostat to adjust the temperature above or below your standard setting, especially when you expect to be out, the more you save. Adjusting the temperature just a couple of degrees while your sleeping will save you money alone but if your home is unoccupied during the day then the savings can be substantial. You can expect a basic programmable thermostat to pay for itself within the first year under the best circumstances and easily within two to three years in circumstances where the adjustments are minimal.