Common Air Handler Problems & Maintenance Schedules

Common Air Handler Problems - Air Handling Unit installed in a tight attic.

With proper maintenance, you can avoid common air handler problems

Common Air Handler Problems - Everyone loves to be comfortable, so when there is a problem with the HVAC system, we can become very uncomfortable. The air handler in the HVAC system has electrical and mechanical components inside it that can experience problems from time to time. Some of the most common problems with air handlers can help you identify the problem and possibly fix the issue — many common air handler problems you can avoid with regular air handler maintenance.

Although some of the issues listed will need the attention of a professional HVAC technician to repair the air handler, after all, an HVAC technician will have all the tools and likely the parts available to make a fast and efficient repair. Furthermore, since every air handler is different it is possible the problems described here do not apply to your situation.

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Refrigeration Pressure Switches | HVAC Systems

What you will learn from Refrigeration Pressure Switches

  1. A question from one of our readers - What are refrigeration pressure switches and how pressure switches protect the refrigeration circuit.
  2. All about high-pressure refrigeration switches
  3. All about low-pressure refrigeration switches
  4. Benefits of refrigeration pressure switches
  5. Refrigeration Pressure Switch Settings
  6. Refrigeration Pressure Switch Wiring Diagram
  7. Lots of related links to help you learn more

Richard - What are pressure switches used in refrigeration circuits and how do pressure switches protect the system from further damage? (more…)

Variable Speed ECM Condenser Fan Motors | HVAC Refrigeration

Variable Speed ECM Condenser Fan Motors are used in condensers for the high efficient models so that the fan speed for the condenser can be modulated according to the load of the system. The ECM variable-speed fan motors are used in condensers that have a modulating compressor. They are also used in condensers that have two compressors or two-stage compressors. The ECM motor adds to the efficiency of the system by modulating the condenser fan motor. The speed matches the compressor that runs based on demand. (more…)

Variable Speed ECM Blower Motors | HVAC Heating & Cooling Systems

Variable Speed ECM Blower Motors

An ECM Variable Speed Blower Motor in a squirrel cage blower

Variable Speed ECM Blower Motors - Variable speed ECM blower motors have become increasingly popular in residential air conditioning and heating systems. From an engineering perspective, these motors increase the efficiency of the systems and offer a whole range of other benefits that help the system and the consumer. Furthermore, comfort is enhanced using ECM blower motors along with noise reduction. (more…)

Condenser Fan Motor Repair | Air Conditioners & Heat Pumps

What you will learn from the Condenser Fan Motor Repair article:
1) Specific description of a motors job along with some technical details
2) Air Conditioner & heat pump fan motor operation
3) fan motor troubleshooting basics
4) Condensing unit fan motor repair warning and disclaimer - Turn the power off before working on the fan
5) Replacing or repairing the motor
6) Why you should replace the capacitor when you replace the motor
7) Conclusion along with lots of resources and related links so you can take a closer look and learn more. (more…)

Thermostat Wiring Colors Code | HVAC Control

Thermostat Wiring Colors Code Page Navigation

    1. Essential Thermostat Wiring Color Guide Including Manufacturers Instructions
    2. Thermostat Terminal Designations Quick Guide - Detail Wiring Color Guide Below
      • Red-Wire - connects to the R terminal with the red wire
      • RC-Wire - connects to the RC terminal RC red
      • RH-Wire - connects to RH terminal RH heat
      • Y-Wire - connects to the Y terminal and is for cooling stage 1 with the yellow wire
      • Y2-Wire - connects to Y2 terminal and is for cooling stage 2
      • W-Wire - connects to W terminal and for heat stage 1 with the white wire
      • W2-Wire - connects to W2 terminal and for heat stage 2
      • G-Wire - connects to G terminal and for fan operation with the green wire
      • C-Wire - connects to C terminal (common 24v power) with the C wire
      • O or B-Wire - connects to O or B terminal and is for reversing valve operation
      • E-Wire - connects to E terminal and is for Emergency heat
      • X or Aux-Wire - connects to X terminal and is for auxiliary
      • S1 and S2 Wires - connects to S1/S2 terminals and is for outdoor temperature sensor
    3. Thermostat Wire Color Code Chart
    4. Tracing the Wire to the Source
    5. Additional Resources

    What you will learn in the Thermostat Wiring Colors Code article:

    1. First, what thermostat wire colors is likely to go to which terminal on the thermostat in your heating and cooling system
    2. Secondly, the function of each wire terminal on the average thermostat highlighting some of the differences in those HVAC system functions from manufacturer to manufacturer as recommended for thermostat wire color
Sometimes, the thermostat is not the problem. Please check this article for a checklist of things to check before calling a heating and cooling repair service.

Thermostat Wiring Colors Code | HVAC Control


Thermostat Wiring Colors CodeAlways follow the thermostat manufacturer’s instructions whenever changing the thermostat. Always turn the power off at the air handler and the condenser and make sure there is no voltage at the transformer before proceeding.

  • Furthermore, the thermostat wire colors below are the most likely colors used for most installations; however, your thermostat wire colors may be different than what the indication is here. There is no official standard for thermostat wire colors. Additionally, thermostat wiring colors are not standardized. However, these are the most wiring methods used based on my years of experience in the HVAC field, where I successfully wired a lot of thermostats and as recommended by manufacturers and common sense for thermostat wiring colors code.

    For instructions on how to wire a thermostat, please see how to wire a thermostat page. Refer back to this page for thermostat wire colors.

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  • Trane Versus Carrier Air Conditioners | Brand Model Reviews

    Trane Versus Carrier Air Conditioners - The first thing we need to do when comparing a Trane Versus Carrier is to make sure we are comparing similar models with similar features.

    Each manufacturer makes various models from a builder’s grade unit, which is usually the HVAC manufacturer’s cheapest model up to the unit that has bells and whistles, and some of these have bells and whistles for the bells and whistles. You want to make sure you are comparing apples to apples and not an apple to an orange.
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    Heat Pump Frost Ice BuildUp | HVAC-Troubleshooting

    Heat Pump Frost Ice Buildup. Hi. I noticed that one of my outside heat pump condensing units was laboring throughout the night. This morning I found ice frost buildup on the heat pump condenser fins. I live in Tucson, Az. It has been colder than normal (below freezing) with a bit more moisture in the air than usual as of late.

    Can you please tell me what causes this frost ice buildup, and how I go about rectifying it? Does this mean that the condenser pump is shot? I’m originally from the Midwest and have never experienced this before. What should I be doing? Thank you for your help. (more…)

    Start Capacitors for HVAC Compressors | Motor Start Assist

    Start Capacitors for HVAC Compressors - Start Capacitor with Potential Relay
    Start Capacitors for HVAC Compressors - HVAC single-phase compressors always come hooked up to a run capacitor. This helps the compressor when it is running, however, very few HVAC compressors come with a start capacitor. Most HVAC technicians know HVAC compressors pull a lot of amps on startup. This large amperage draws on startup is referred to technically as locked rotor amps or inrush current. It can be as much as 40,000 watts or more of pure power to get an HVAC compressor started. (more…)