The purpose of this HVACR training project is to visually show your students the change in the amount of liquid flowing through a TXV or...

When servicing an air conditioner or heat pump, we often notice a low airflow problem which needs to be fixed. If there is no indoor air...

If you suspect that an evaporator coil is clogged with dust but cannot visually see it, such as when you can't directly inspect on a...

Measuring airflow is one of the most commonly missed or ignored topics in HVAC when commissioning or diagnosing problems in systems. I...

Today most people are aware of the invisible, odorless, poisonous gas of Carbon Monoxide or CO for short. Now we know that even low...

Problem #1: No Power to the Package Unit On all HVAC systems, power is critical to operation, and a package unit is no different. There...

This article covers the ten most common locations where refrigerant leaks may be on an air conditioning system. An electronic leak...

It is certainly important to have good training and/or experience in the field prior to applying for an HVAC/R position. However, some do...

This article covers the 10 most common reasons the blower fan does not turn on! A blower motor may be installed in a forced air gas or...

In this article, we discuss the accumulator tank, its function, why its used, and its location in the system. The photo below shows the...

Swaging tools are used to expand the end of a copper tube to accept the next section of tubing. This is done prior to making a permanent...

The Purpose of a Start Capacitor A start capacitor can be found in the electrical compartment of most single speed heat pumps and some...

Basic Characteristics of a Good Instructor "The hardest year of teaching is the one you are currently in." ...

If a furnace or air conditioning system develops an airflow problem, there are several items to visually inspect. If visual inspection...

An attic fan is used to lower the temperature within the building shell between the roof structure and the living space. The fan's job is...

There are four methods for bending soft copper tubing. Copper tubing can be bent to the correct measurement using a lever type bending...

Fuel gases such as Propane or Natural Gas are a regular part of everyday life for many. Whether it is used to heat a home, cook a meal,...

On a natural gas or propane furnace, there are typically 6 main reasons why a blower fan motor may not shut off and just continues to...

This article explains how to troubleshoot a refrigerator or freezer compressor that does not start. There are different components that...

In this HVAC Training Article, I discuss how to perform electrical troubleshooting on an HVAC/R compressor to determine if it is bad. Too...

A Cad (Cadmium Sulfide) Cell is a photo conductive flame detector that changes its electrical resistance depending on how much light is...

This article explains the "Top 5 Problems" that can occur on a contactor and how to troubleshoot them! The HVAC Contactor is a device...

Just because your company only uses one type of port cap doesn’t mean you won’t be called to service a system with another manufacturer’s...

When installing a new HVAC system, replacing an existing HVAC system, or only replacing one part of the system, there is a sequence of...

Downloadable Wiring Diagrams and the measurement layout are available at the bottom of this page. Instructors are always looking for a...

The question we are looking to answer is, should we install the TXV bulb before (upstream) or after (downstream of) the external...

In this HVAC training article, we will be discussing how to adjust the fan speeds on an indoor ECM variable speed blower motor and an ...

In this HVAC training article, we will be discussing how to adjust the fan speeds on an indoor PSC blower motor in furnace and air...

This article explains how the thermocouple, gas valve solenoid, and pilot flame work on a water heater. I will be discussing 10 problems...

In this HVACR Training article, we are using electrical resistance measurements on the PSC compressor terminals in order to determine...

In this article, we will be discussing methods to test the safety switches in a gas furnace using a multimeter. These switches include...

In this HVAC training article, I discuss 20 AIRFLOW Problems that you may find on ducted gas furnaces, air conditioners, heat pumps, air...

In the world of HVAC, low voltage shorts are a common occurrence on a service call. Low voltage shorts occur when an electrical circuit...

A refrigerant leak may be easy to find when the leak is a large one but when the leak is small, finding it can be tedious and time...

In this step-by-step installation, we will be covering the full installation of a ductless Mini-Split heat pump system. This system...

In order to troubleshoot a gas furnace, the technician must have a thorough knowledge of each component that could be in the unit....

Diagnosing if a control board is bad on a furnace, air conditioner, or heat pump may seem difficult but here are some simple tips and...

How can you tell if you have a clogged liquid line filter drier? If there is a noticeable temperature drop from one side of the filter...

Is there an easy way to tell if a mini-split ductless unit is low on refrigerant? Yes, if the Delta T is low and the system continues to...

I put this list together to make sure that HVACR technicians don’t have to undergo the same frustrations, loss of time, and expenses that...

Can you check the charge on a system without checking pressure? Sure, remember that the only reason we check pressure is to convert it to...

In this article, we will discuss an HVAC unit’s refrigerant pressure on both the high side and the low-pressure side while the system...

In a dry climate, certain considerations must be taken prior to installing or servicing air conditioning systems. A TXV metering device...

There are many ways that technicians have tried to get around actually checking the charge of air conditioners and heat pumps with...

On a mini-split ductless system, two copper tubes are needed to transport the refrigerant. These copper tubes are referred to as the line...

A question that I get asked frequently is “Can I check the charge of a mini-split ductless unit with superheat and subcooling the same...

Most technicians in the HVAC field know the normal range of operation for the low-pressure side of an air conditioning system. This tends...

In this article, we will define both superheat and total superheat, calculate total superheat, explain how to use total superheat to...

In this article, we will define subcooling, calculate subcooling, explain how to use subcooling to check the refrigerant charge, and show...

Regardless of the type of system or brand of thermostat, it is important to understand that there are many issues that can prevent a...