If you plan to check the pressure on your heating and cooling appliances on your own, you’ll need what’s known as an HVAC gauge.
Also known as manifold gauges, these appliances can detect low pressure, high pressure, and so forth and are primarily used as diagnostic tools. You can use one to determine if there’s a leak in your air conditioner or heat pump before calling the technician.
Digital gauges are particularly common today as they are easier to read, thanks to the LCD screens. The digital manifold also offers more precise readings. If you plan to acquire one, this guide will help you pick the right one.
Let’s begin with a review of 10 of the best digital HVAC gauges based on performance, price, and customer support.
What’s an HVAC Gauge?
An HVAC gauge, also known as an HVAC manifold gauge or just an HVAC manifold, is an HVAC pressure-checking kit. It’s purposely designed to check or monitor the pressure of refrigerants in cooling and heating appliances.
The HVAC gauge can be small or reasonably large, depending on the application. Smaller handheld gauges target individual DIYers who’d like to check the pressure on their air conditioners and heat pumps independently. In comparison, larger gauges mostly target technicians who work with larger HVAC systems in commercial settings.
The typical HVAC gauge can be used in the following ways
- To check the pressure in AC lines
- To determine if there’s a leak
- To add small amounts of refrigerants
- For refrigerant evacuation
- In HVAC system troubleshooting
- To replace cooling and heating systems
Remember that, although every HVAC gauge measures refrigerant pressure, each gauge can only measure the pressure in specified refrigerants. The good news is that most manufacturers clearly state the refrigerants supported by each of their products.
Since all heating and cooling systems carry a stamp stating the refrigerant used, all you need to do is cross-check to ensure that the gauge’s list of supported refrigerants includes your AC/heater’s refrigerant.
How Do HVAC Gauges Work?
It’s a straightforward process. But to fully understand it, you first need to understand the different parts of a digital pressure gauge.
While manifold gauges will differ slightly depending on the manufacturer and model, they share a few common traits. A standard manifold comprises two gauges – a blue low-pressure valve on the left and a red high-pressure valve on the right. The valves attach to a center manifold.
The center manifold typically consists of three or four ports, i.e., a low-pressure port that connects to a blue hose for vapors, a high-pressure port that connects to a red hose for gases, and a center port that connects to a yellow service hose for recovery and recharging.
The center area where everything is connected is called the manifold, which explains the name “manifold gauges.” This manifold has two functions. One, it serves as a porting station. Secondly, it permits gases and liquids to flow through its molded body. The flow is controlled by valves attached to the manifold.
The following is a summary of how the pressure measurement process works for pressure reading, vacuuming, and adding refrigerants;
- Pressure reading: Connect the red hose to the HVAC high-pressure line and the blue hose to the low-pressure line. Then look at the gauges and record the desired readings.
- Vacuuming: Connect the yellow hose to the vacuum pump and the blue hose to the unit. Leave the blue valve open so that the vacuum can run. Then, record the readings.
- Adding refrigerant: Connect the yellow hose to the external refrigerant bottle and the red hose to the HVAC unit. Then monitor the refrigerant top-up and stop the process when you’ve added enough refrigerant.
Analog vs. Digital HVAC Gauges
There are two main categories of HVAC gauges – analog and digital. Analog HVAC manifold gauges, also popular as mechanical gauges, have been around longer. They often feature a round dial and needle appearance and comprise inner mechanical gear and shaft assemblies.
The analog manifold gauge is a compound gauge, meaning that it measures pressure above and below zero. As such, the manifolds must be calibrated at zero according to your elevation level.
A key advantage of analog manifolds is the low maintenance costs. For one, these devices don’t need batteries or recharging.
Digital manifolds are, however, the more popular of the two options. They operate on the same principles as analog manifolds but are superior for obtaining accurate pressure readings. Also, the pressure readings can be automatically converted to saturation temperatures.
Built-in pressure and temperature charting software, thermostats for measuring liquid and suction line temperatures, and clamps that enable faster readings are the other significant advantages of digital manifolds. More-modern digital HVAC manifolds can also connect wirelessly to smartphone apps via Bluetooth or Wi-Fi for remote reading.
Top Considerations When Choosing the Best Digital HVAC Gauge
The specific features and considerations when choosing a digital HVAC manifold will depend on your needs. However, the following are some of the most important factors;
- Durability: The best digital manifolds are made from metal for durability. Aluminum and brass are some of the best materials as they are rust-proof. Plastic fittings are undesirable as they develop leaks quickly and tend to corrode faster and
- User-Friendliness: Choose an HVAC manifold that you’re comfortable using. An instruction manual to help you understand the system and color chart to guide you through the different color codes are especially important.
- Refrigerant types: The number and specific refrigerants supported is also critical. You want a manifold that supports a lot of different refrigerants. More importantly, it must support the refrigerants you use most often.
- Sighting glass: The sighting glass allows you to watch what’s going inside the manifold and are especially valuable when recharging a system in its liquid phase. You can easily monitor the progress of the recharging process.
- Bluetooth/smart connectivity: Not all digital HVAC manifolds are smart. If you want to send readings to your smartphone from the manifold remotely, make sure it has Bluetooth connectivity and, ideally, an app.
- Other considerations: Extra features, such as USB ports, integrated adapters, alarms, temperature clamps, and hose parks, are also important. Don’t forget to consider the warranty too.
HVAC Gauge Frequently Asked Questions
How do HVAC gauges work? HVAC manifold gauges work by reading the pressure of various liquids and gases in home cooling and heating systems.
What is purging in HVAC? Purging is the process of clearing an air conditioner’s internal lines and hoses. It’s often done before recharging.
How bad is Freon for you? Freon is a tasteless, mostly odorless gas. When inhaled in substantial quantities, it can cut off the oxygen supply to the cells and lungs.
What is the PT chart used for? The pressure-temperature chart is used to set coil pressure to generate desired temperatures, check the amount of sub-cooling below the saturated liquid condition, and check superheat levels above the saturated vapor condensation.
Best Digital HVAC Gauges Reviews
1. Testo 550 Digital Manifold Kit for Air Conditioning
- Efficient: The testo 550 with its sturdy housing and 2-way valve block was particularly created for harsh environments and offers data storage for up to 60 refrigerants
- Accurate: Thanks to two temperature compensated pressure sensors, the wireless manifold determines high and low pressure as well as evaporation and condensation temperature
- Multiple functions: The digital manifold features the display of temperature difference, temperature compensated leakage tests and calculation of superheating and subcooling
- Set: Includes two pipe clamp temperature probes for reliable measurement of the pipe temperature, as well as three 5 feet long hoses suitable for all common refrigerators
- Smart App: Conveniently follow the measurements via Bluetooth from a smartphone or tablet. Send results directly from the job site for a more convenient documentation
If you’re a non-expert in HVAC maintenance/repairs or just getting started in the industry, the Testo Model 550 is one of the most popular digital manifold kits, and for a good reason.
The Model 550 is a robust gauge designed with 2-way metal valve blocks with three connections and three hose parkers. It also features a suspension hook, an illuminated display, and rugged housing to boot. These features make it an excellent choice for harsh working conditions.
The gauge stores 60 different refrigerants in just one instrument and accurately measures high and low pressure as well as evaporation and condensation temperatures. An automatic heat mode means you don’t need to switch refrigerant hoses.
Attached to the two temperature inputs is a pipe clamp probe that reliably measures pipe temperature while simultaneously providing superheating and sub-cooling values.
Remember that Testo has a handy refrigeration app from where you can find all these readings. The app works from up to 60 feet away, offering a convenient way to monitor measurements graphically or in raw numbers remotely. You can swiftly send the app readings to the job site via email.
It measures pressures up to 60 bar and can also be used for temperature-compensated leakage tests. A 2-year limited manufacturer warranty backs the gauge.
- Robust design for harsh conditions
- supports Bluetooth
- Supports remote monitoring with mobile app
- Enjoy a 2-year warranty
- It maxes out at 60 refrigerants
2. FieldPiece SMAN460 Wireless 4-Port Digital Manifold with Micron Gauge
- Extra rugged design. Units of Measurement- Psig, kPa, MPa, bar, inHg, and cmHg. Measures-2 Pressures, 2 Temperatures
- Live real-time adjustments with wireless measurements
- Micron vacuum gauge with alarms, stopwatch, and rate indicator
- Large 3/8" full bore and VAC port.4 Ports for one time hookup:Connect to high side, low side, vacuum pump, micron gauge, and recovery machine (or refrigerant tank). Then use the valves as needed to recover, evacuate and charge the system
- All measurements on screen at one time
Another exceptional gauge to consider is the model SMAN460 from FieldPiece. It’s a wireless manifold with multiple useful features that make it a good value for the price.
For one, it offers automatic calculations of the desired superheat, synchronized sub-cooling, and actual superheat temperatures, as well as nine more readings on a single screen, so you can find all the information you need in one place.
Another valuable feature to look forward to is the 4th port that allows you to make the vacuum faster and collect gas from the system. This function, combined with the wireless ability that gives you real-time readings, allows you to know what’s happening inside your refrigerator or other systems while it’s charging.
A built-in vacuometer allows technicians and professionals to set the alarm or stopwatch (you can even set up both simultaneously) to track micron levels and the resolution rate. You can activate the alarm for high micron readings, in which case the timer freezes when the system reaches the selected micron level.
There are many other exceptional qualities about the model SMAN460 from FieldPiece. For instance, the large size 3/8-inch vacuum hole allows faster retrieval and evacuation. The extra-rugged design also makes it more attractive for unnatural applications.
- The four ports allow for one-time hook-up
- All-in-one display
- Maximum pressure up to 60 bar
- Compatible with 64 different refrigerants
- Backed by a 1-year warranty
- The handle quality is average
- A bit expensive at close to $1,000
3. AUTOOL Digital Refrigerant Manifold Gauge set HVAC with Hose
- The intelligent electronic refrigerant group instrument is an auxiliary instrument for the installation, testing and maintenance of refrigeration equipment such as air conditioners,fridge and cold storage. The instrument has double pressure test, dual temperature test , digital readout, multi-unit switching, multi-mode function and built-in refrigerant database.
- Measures double pressure at the same time, as well as dual temperature measurement , equipped with automatic multi-unit pressure conversion, automatic conversion of temperature Celsius / Fahrenheit, to facilitate different needs. Built-in 89 kinds of refrigerant pressure-evaporation temperature database, also calculate the subcooling superheat, to facilitate direct reading of operating process data.
- Large-size liquid crystal display, LCD backlight support, data display clear and easy to read, convenient light operation. Long-life valve switch, 1/4-inch standard interface design to ensure that the instrument's durability and versatility.
- Also it tests percentage of vacuum measurement; pressure leak measurement, leak time speed record. It is deserved to have this multi-functional, accurate and simply operated digital manifold let you do the job effciently.
- Uses high-strength engineering plastics and flexible non-slip silicone design, the whole machine is solid and comfortable to hold. Built-in 32-bit digital processing unit and high-precision data acquisition unit, high data and stability. To ensure your shopping experience, we free provide 3 years warranty for all AUTOOL main unit products. Please purchased it without worries.
The best digital HVAC gauges tend to be a bit pricey. A quick check shows that the majority are priced over $200. If you’re looking for something more affordable without losing too much quality, this feature-packed AUTOOL model would be an ideal pick for installing, testing, and maintaining refrigeration equipment such as air conditioners, fridges, and cold storage units.
The instrument has double pressure tests, dual temperature tests, a digital readout, a built-in refrigerant database, multi-unit switching, and a multi-mode function, among other features.
It also features a built-in 32-bit digital processing unit and a high-precision data acquisition unit for increased accuracy and stability. You can use it for pressure leak and leak time speed tests.
A large Liquid Crystal Display (LCD) backlight support clearly displays all the above information, while the long-life valve switch and ¼-inch standard interface design ensure the instrument’s durability and versatility.
However, a key quality that stands out about this gauge is the fact it supports up to 89 different refrigerant types. This is more than even some of the more expensive HVAC gauges. An automatic multi-unit pressure conversion function makes your work easy.
- Flexible, non-slip silicone design
- Supports up to 89 different refrigerants
- Offer maximum pressure rating of 60 bar
- Backed by a valuable 3-year warranty
- No remote app/Bluetooth operation
4. Uniweld USMAN5 SmarTech Wireless Digital Manifold
- 5 Ft. Hoes Set Included: 5 ft. red EZ Turn hose, a 5 ft. blue EZ Turn hose with a EZ Access "T" Fitting built in for micron gauge connection, a 5ft. 3/8" hose for 3x faster evacuation of the system
- BLE (Bluetooth Low Energy) wireless module connects to your iOS and Android smart device through Uniweld's SmarTech App (Free Download). Smartphone pictured not included
- Superheat and Subcool Automatically calculated in real time by the SmarTech App
- Export a SmarTech Verified Report and email system performance data as a PDF or CSV file
- Protective Rubber Boot and easy access double zipper padded case with storage pockets
Uniweld’s USMAN5 SmarTech wireless digital manifold combines the superior craftsmanship of Unweld manufacturing and the wireless capabilities of your Android or iOS device to make it easy to install, test, and maintain your HVAC appliances. It pairs effortlessly with your smart devices via Bluetooth through Uniweld’s SmarTech app (downloadable for free).
Once connected, the instrument allows you to monitor target, and actual superheat and sub-cooling calculations in real-time as the temperature and pressure levels rise and fall. A color-coded Smart Charge Zone feature takes the guesswork out of the equation by allowing you to differentiate the charge levels.
RED signals an overcharged system, BLUE represents undercharged, and GREEN means adequately charged.
You’ll also appreciate that the gauge supports 111 different refrigerant types. You can create a list of your most commonly used refrigerants in the app. More importantly, you can export a SmarTech Verified Report and send to the job site the system performance data as a CVS or PDF file.
The Uniweld USMAN5 kit includes a 5-foot red EZ Turn hose, a 5-foot blue Turn hose with EZ Access “T” Fitting built-in for micron gauge connection, and a 5-foot 3/8-inch hose for 3-times faster system evacuation. A protective rubber boot and easy-access double-zipper padded case with storage pockets mean the instrument is ready to go anywhere.
- 3/8-inch refrigerant tank adaptor included
- 2 x K-Type bead probe thermocouples included
- Bluetooth support for wireless smartphone app use
- Compatible with 111 refrigerant types
- Backed by a 2-year warranty
- Pressure rating up to 20 bars
- It comes with a high price tag
5. FieldPiece SM380V SMAN Manifold Gauge Set
- SMAN Manifold Micron Gauge (3 Port)
- Newly designed SMAN manifold
- Replacement for SMAN300 series
- Three valve manifold with micron gauge
- Toughest, most advanced digital refrigerant manifold on the market
For about half the price of the SMAN460, you can acquire another excellent FieldPiece manifold gauge set – the Model SM380V SMAN.
This manifold gauge set is a three-port system (instead of the SMAN460’s four ports) with a micron gauge. It replaces the SMAN300 series (including the SAMAN320, SMAN 430, and SMAN360) and doesn’t require the JL2 transmitter for wireless connections.
The manifold set is packed with power and experience, combining feedback from years of A/C and refrigeration with FieldPiece’s laser focus on continuous improvement to bring you the toughest, most advanced digital refrigerant manifold gauge set.
The heavy-duty casing, reinforced hook, impact-resistant screen, water-resistant proof design make it the ideal choice for unnatural applications, while strategically positioned thermocouple ports and hermetically sealed sight glass ensure the SM380Vcan withstand the rigors of field use.
Advanced features, including data logging to store up to 9 jobs internally and tightness test checks for leaks, streamline your job for the best experience.
An easy-access USB port makes it easy to download the data you need, while the large LCD screen displays the percentage of free storage.
You can log continuously for the whole week (7 days). Among others, the screen allows you to view pressure differential, track duration of tests, and track temperature compensated with SL, and receive wireless measurements.
- It’s a three-valve manifold with micron gauge
- A rugged design ideal for field use
- Has USB port to download your data
- Log data continuously for 7 days
- It feels a little complex
6. MasterCool 99872-A Blue R134A Digital Manifold Gauge Set with 72-Inch Hose
- USER FRIENDLY DESIGN allows the technician to obtain refrigerant and oil capacity readings for the most popular automobile manufacturers
- LARGE EASY TO READ LCD displays temperature, pressure and vacuum readings for R134a
- LONG LASTING PERFORMANCE AND DURABILITY provided by manifold case which is constructed of ABS material and protected by a rugged rubber boot
- PERFORMS SYSTEM LEAK CHECK at the conclusion of the evacuation process
- COMPLETE KIT INCLUDES R134a digital manifold, (3) 72” R134a hoses and a set of manual couplers packaged in a blow molded case
MasterCool is a household name in the HVAC industry and makes some of the best climate systems gauges. The best part is that their pressure gauges are color-coordinated for convenient use. Model 99872-A is one of the company’s best creations to date.
It’s designed with a large LCD screen that displays all the important readings (pressure, vacuum, and temperature) and packed with multiple features to help get the job done fast.
It’s also a very durable instrument. A manifold case designed for ABS materials and secured by a rugged rubber boot means you can take it pretty much anywhere.
Besides the standard functions, the Model 99872-A performs system leak testing at the end of the evacuation process and provides all the information you need to make important maintenance decisions.
The user-friendly design allows the technician to obtain refrigerant and oil capacity readings for the most popular automobile manufacturers.
The complete kit includes an R134a digital manifold, (3) 72-inch R134a hoses, and a set of manual couplers packed into a bow-shaped case. At under $200, it’s one of the most value-for-money manifold sets.
- Large LCD screen for easy reading
- User-friendly design
- Durable design with all metal parts
- Complete for out of the box use
- Meets UL, SAE, and EPA requirements
- Backed by a 1-year warranty
- There have been complaints about accuracy
- Only supports 44 refrigerant types
7. Testo Model 0563 557 Digital Manifold Kit with Bluetooth and Set of 3 Hoses
- Efficient: The testo 557 is ideal for servicing air conditioners, refrigeration systems and heat pumps and replaces the multitude of tools needed by HVAC/R contractors and technicians
- Versatile: Accurately measure high and low pressure, evaporation and condensation temperature and take advantage of the automatic calculation of superheating and subcooling
- Convenient: Thanks to the 4-way valve and automatic heat pump mode, there is no need to switch over to different refrigerant hoses, which enables a quick and easy application
- Set: Includes two pipe clamp temperature probes, one external pirani probe for vacuum measurement and a set of four hoses, as well as a protective hard-shell case
- Refrigeration App: Follow all measurements remotely via Bluetooth from a smartphone or tablet. Send results directly from the job site for a more convenient documentation
We’ve already mentioned one Testo gauge, the model 550. The model 0563 is a slight advancement of the 550, offering more features and greater accuracy.
The two thermistor probes and vacuum gauge guarantee exceptional accuracy, while the 4-way valve block, large backlit display, and sight glass combine to ensure unmatched flexibility.
Better still, the model 0563 557 comes with a complete kit that includes four hoses, each 5-foot long. Three of the hoses (red, yellow, and blue) have 7/16-inch UNF, while the fourth (yellow) hose has 5/8-inch UNF. It supports 60 different refrigerants. The kit also includes two pipe clamp temperature probes, one external Pirani probe for vacuum measurement, and a protective hardshell case.
This innovative manifold gauge set reviews measurements via Bluetooth on your smartphone or tablet with the Testo refrigeration app up to 65 feet away, allowing you to quickly and conveniently document your job and send reports via email to the job site.
The app also allows you to directly upload new refrigerants into the manifold and generate lists, trending graphs, and tables to analyze system performance. A 2-year warranty backs it.
- Features 2-line backlit display
- Compact design with rugged body
- It comes with a complete kit
- Convenient refrigeration app
- Backed by a 2-year warranty
- It’s one of the pricier Testo gauges
8. BELEY Refrigeration Digital Manifold HVAC System Gauge Set
The Beley single-gauge intelligent toolset is an auxiliary instrument for installing, testing, and maintaining refrigeration equipment such as air conditioners and fridges.
It can measure dual pressure and dual temperature readings simultaneously and features an automatic multi-unit pressure conversion function as well as a function to automatically convert temperature from Celsius to Fahrenheit and vice versa to facilitate different needs.
The manifold set supports 89 different kinds of refrigerants and has a pressure-evaporation temperature database. It effortlessly calculates sub-cooling and superheat levels and can test the percentage of vacuum, pressure leaks, and leak time speed. All the data is displayed on a convenient LCD backlit screen.
The Liquid Crystal Display (LCD) screen clearly displays data for easy reading. It’s a ¼-inch standard interface that’s backlit so that you can use it even in the dark. The switches are designed for life.
Durability is vital when selecting a manifest gauge set, and this BELEY instrument guarantees many years of worry-free use. It’s made from high-strength engineering plastic and features a flexible, non-slip silicone design. Most importantly, each purchase comes with a 24-month limited manufacturer warranty for your peace of mind.
- A high maximum pressure rating of 60 bar
- Compatible with up to 89 different refrigerants
- Durable build and non-slip design
- Backed by a 2-year warranty
- It’s a low-quality build
- No app/Bluetooth control
9. Elitech PT-500&PT-800 Wireless Refrigeration Digital Manifold Gauge Set
There are many great digital manifold gauge sets to consider, but very few can match the EliTech range of products for simplicity. You don’t need any special technical knowledge to hook the model PT-500&PT-800 or interpret readings on the screen. Moreover, you can view the measurement data on your smartphone, allowing you to complete the job quickly.
The EliTech manifold gauge’s key features include support for multiple refrigerants and units and automatic calculation of superheating and sub-cool measurements. The instrument measures up to 140 different refrigerant types, the highest on this list.
It can also be alternated between seven measurement units. The calculations, recording, reporting, analysis data, and more are directly passed to your smartphone via Bluetooth up to 99 feet away.
The free-to-download EliTech Pressure Gauge app quickly receives remote notifications when readings move beyond predetermined values. You can set alarms within the app as appropriate for high/low pressures. Data from the app is saved and can be exported in Excel and PDF format to your personal computer and the workstation.
The pressure gauge is made by ABS and PPT and boasts a waterproof level of IP65. It’s accurate to +/-10% and offers a decent maximum pressure rating of 55 bar. Buyers get 24/7 US technician support via email and phone.
- Supports up to 140 different refrigerant types
- Smart control via mobile app (iOS and Android)
- Waterproof to IP65
- Backed by a 1-year limited manufacturer warranty
- It’s very affordable
- The app is underwhelming
10. DUI DY517A Refrigeration Digital Manifold Gauge Meter with Test Clip and Pipe
Finally, the DUOYI DY517A is a dual pressure test, dual temperature test instrument with digital readings and multi-unit switching capabilities, plus a built-in refrigerant database.
It’s a durable unit built from high-strength engineering plastic and features a flexible non-stretch silicone design, making it solid and comfortable to hold.
A built-in 32-bit digital processing unit ensures exceptional accuracy and high data stability, while the large backlit LCD screen makes it easy to read measurements even in the dark. The long-life valve switch guarantees equipment durability.
This pressure gauge is designed to measure up to 10 mph (bar). Make sure to confirm the rated pressure value of the equipment under test before testing. If the rating exceeds the range of the instrument, find a different measuring instrument.
You’ll appreciate that the DY517A supports up to 89 different refrigerant types, a lot more than some expensive alternatives. It also calculates superheating and sub-cooling to simplify direct reading. Besides the normal applications, this instrument can be used for vacuum measurements, pressure leak measurement, and leak time speed checks.
The manufacturer strictly prohibits using or storing the instrument in high temperature, high humidity areas, or places with a strong magnetic field as these conditions can compromise the performance.
- Durable build
- Full kit with test clip and pipe
- Measures double pressure simultaneously
- Multi-mode functions
- No mention of warranty
If you plan to recharge and troubleshoot your heating and air conditioning systems on your own, you’ll need an HVAC manifold gauge. You can always choose analog models, but the modern digital models are easier to read and more accurate.
Make sure it’s a durable, user-friendly, and smart model that performs automatic calculations and sends reports to your email. Above all, make sure it supports the types of refrigerants you frequently use.