Your browser is out of date.

You are currently using Internet Explorer 7/8/9, which is not supported by our site. For the best experience, please use one of the latest browsers.

How to Read HVAC Gauges

Keeping your HVAC system tuned helps it work more efficiently. Maintenance and repair technicians use specific tools to test and update cooling equipment. A gauge set is one of these tools. This device tests the pressure of gases and liquid in a cooling system. This tool can also be used to read vacuum pressure. Gauge sets are a necessity for anyone testing and diagnosing problems with an air conditioner.

Types of HVAC Gauge Sets

An HVAC gauge set is also called a manifold or a manifold gauge. There are two types of manifold sets. One is digital, and the other is analog. Digital manifold gauges are popular because the testing process is easy and happens quickly. The data from a digital gauge is highly accurate.

An analog manifold gauge set has two gauges instead of a digital readout panel. The technician must be able to read the gauges properly to get the necessary information. Analog gauges provide a general understanding of what's happening. Conversion errors by the technician can cause a misreading.

HVAC Components and Parts

Analog gauge sets have two gauges at the top. The manifold body sits below the gauges, and hand valves are found on either side of the manifold body. A set of hoses attaches to the bottom of the manifold body. Digital gauge sets have a digital panel with a series of operational buttons instead of actual gauges. A manifold body is attached below the digital panel. Hand valves are located at either end of the manifold body.

Property owners in Grove can get assistance from B & B Heating & Air Conditioning for all their HVAC problems. We're available to solve your repair and maintenance needs on central air conditioners and packaged systems.

Choosing the Right Gauge Set

Choosing between a digital or an analog gauge set is a personal preference. Digital sets are often designed to do far more than an analog set. However, for simple reference and general use, an analog gauge set may be a good solution.

The most important characteristic of a gauge set is the type of refrigerant it's designed to test. Refrigerant types are noted with an R placed before the refrigerant number. Some AC refrigerants, such as R22, have been phased out of use. Safer refrigerants are being used in high-performance AC equipment. Most technicians carry more than one set to help them do their work. The three basic sets are a R410A manifold gauge set, a R22 manifold gauge set and a R134a manifold gauge set.

Color Coding on HVAC Gauges

The high pressure side of the gauge is red. The low pressure side of the gauge is blue. The middle hose is not used to read pressure. Instead, it is used as a disposal line to discharge refrigerant. This is an industry standard that helps prevent accidents. Most gauge manufacturers thread and size each side differently, so the user doesn't connect them incorrectly.

Connecting the Gauge Hoses

You should read the manufacturers specification to understand the correct use of your gauge. It is relatively simple to do. First, turn off unit, and then connect the high pressure gauge hose to the high pressure connection on the unit. Next, connect the low pressure gauge hose to the low pressure connection. Finally, turn on unit, let run for about 15 minutes, and then use the gauge to take the readings.

When it's time to remove the connections, make sure the AC unit is turned off. Be aware that pressure has built up during the reading process. During hose removal, proper placement of the hands is necessary. Your hands and fingers can receive a refrigerant burn if they aren't in the right position.

HVAC Safety Certifications

Mishandling of AC and HVAC equipment and a manifold gauge can cause the release of refrigerant into the air. A refrigerant is an odorless gas that is harmful when inhaled. Make sure your technician has the proper EPA certification before servicing your unit.

B & B Heating & Air Conditioning Grove has been named one of the top 25 Lennox dealers in America. We're a locally owned and operated service company, and we've been delivering professional results for more than 30 years. Our AC and heating team is filled with experts on solar-ready systems, heat pumps, air handlers and much more. Call us today to schedule an appointment for your home in the Grove area.

About Us

B & B specializes in both the Residential and Commercial Markets for Heating & Air-Conditioning products and services. We also are pleased to offer a variety of Indoor Air Quality Products.

Learn More

Resources

For the benefit of our customers, resource information on a variety of topics, products and services is available including: Federal Tax Credits, Financing & Rebates, Special Offers, Product Videos, and more.

Learn More

Let's Work Together

Get in touch with us and send some basic info about your project.

BOOK NOW

Local Same-Day Service Guaranteed!