Author: Meggan Kessler

Getting the refrigerant charge right isn’t just good practice — it’s essential. From system performance to energy efficiency and long-term reliability, charge accuracy is crucial. Whether you’re servicing air conditioning units running on R-32 or handling a refrigeration system using R-134a, the rule is the same: the system charge needs to be accurate.

A properly charged system:

• Runs more efficiently
• Maintains stable temperature control
• Protects the compressor from unnecessary wear

But an incorrect charge – whether too little or too much – can lead to poor system performance, excessive wear and even premature failure.

 

Undercharging: A Slow Burn Toward System Failure

Undercharging an HVACR system does not just impact the performance of your system—it will also actively damage the system’s components and ultimately lead to costly failures. When a system is undercharged, it lacks the proper volume of refrigerant needed to absorb and move heat efficiently. This will result in poor cooling or heating performance as the evaporator cannot reach the temperature required to facilitate the needed heat transfer.

Undercharging can also place significant stress on the compressor. With an insufficient amount of refrigerant returning to the compressor, the pressure on the suction side will drop. This can cause the compressor to operate at higher temperatures, increasing the risk of the compressor overheating. One of the more dangerous outcomes of an undercharged system is the freezing of the evaporator coil. As the pressure and temperature drop too low, moisture condenses and freezes on the coil, eventually blocking airflow. Once airflow gets restricted, pressure starts to build up, and the compressor has to work much harder, pushing the whole system further away from the operating range.

 

Why Overcharging Can Lead to Liquid Slugging and Total Compressor Failure

On the other hand, overcharging a system can be just as damaging and comes with its own set of problems. With too much refrigerant in the system, pressures throughout the circuit rise. This elevated pressure forces the compressor to work harder than necessary, increasing energy consumption and reducing overall system efficiency. Over time, the strain can lead to compressor overheating, damaged valves, or even mechanical failure. Unlike undercharging, which often presents slowly over time, overcharging can sometimes lead to immediate shutdowns if high-pressure safety controls are triggered.

A particularly harmful result of overcharging is liquid refrigerant making its way back to the compressor — a phenomenon known as liquid slugging. Compressors are designed to compress gas, not liquid, and when liquid enters the compressor it can cause internal components to break. This kind of failure is catastrophic and typically leads to total compressor replacement.

 

Get the Charge Right – Every Time

How do you make sure the refrigerant charge is accurate? The best practice is to follow the equipment manufacturer’s installation and service manuals. Depending on the system type and metering device, refrigerant charge is set by superheat, subcooling or by refrigerant weight. Plus, you will need to take into account the airflow at the indoor unit.

Whether the system uses R-134a, R-410A or any other refrigerant, the core principle remains the same: the charge must be precise. Even a slight deviation can throw the system out of balance, compromise performance and reduce the system’s life span. Get the job done right by using field-tested tools like the Fieldpiece JL3KH6 Job Link®  charge and air kit and the SR47 digital refrigerant scale.

Accurate charging doesn’t just help systems perform better – it saves your customers money and helps prevent call backs.

When you’re handling service calls and installations with pre-charged line sets, reach for a wireless probe kit for the most efficient and practical way to tackle the job. Lightweight, hose-free and packed with functionality, these kits give HVACR pros the flexibility to work smarter, not harder; all while ensuring every job is documented and done right.

 

Lightweight Convenience, Heavyweight Performance

Manifolds and hoses have their place, but wireless probe kits like the JL3KH6 Job Link® Probes Charging and Air Kit, JL3KR4 Job Link® Probes Charge Kit and JL3KM2 Job Link® System Dual Port Manometer Probe Kit are designed to be compact and easy to carry. Whether you’re working on a rooftop, in a crawl space or simply moving from service call to service call, these kits lighten your load without sacrificing performance.

 

Direct Connection Where You Need It

With wireless probes, you tap into the system right where you need the measurements. This means faster setup and quicker readings. Whether you’re checking pressure, airflow or temperature, probes give you instant access.

 

Minimal Refrigerant Loss

Every time you disconnect hoses from a system, you lose valuable refrigerant. Using wireless pressure probes can significantly reduce refrigerant loss. With direct attachment and no long hoses to trap refrigerant, you maintain the integrity of the system and protect the environment.

 

System Data in the Palm of Your Hand

With Fieldpiece wireless probes you’ll have full system diagnostics right on your smartphone or tablet with the Job Link® System App. Get real-time data on pressures, temperatures, airflow in one convenient snapshot. Plus, easily generate professional reports for your customers.

 

Which Fieldpiece Kits Are Right for You?

• JL3KM2 Job Link® System Dual Port Manometer Probe Kit: Essential for fast, accurate static pressure readings and airflow diagnostics.
• JL3KR4 Job Link® Probes Charge Kit: Perfect for quick, reliable pressure readings and checking superheat and subcooling.
• JL3KH6 Job Link® Probes Charge and Air Kit: A full solution – includes pressure, temperature and airflow probes – for total system checks on the go.

Each kit offers a lightweight design, direct connectivity and seamless integration with the Job Link® System App that makes your service calls and installations faster, cleaner and more professional.

 

Bring a New Level of Professionalism to Every Job

Fieldpiece probe kits not only make your work easier, they show your customers you’re using cutting-edge tools to ensure their systems are serviced to the highest standards. In today’s competitive HVACR market, standing out with precision, efficiency and professionalism isn’t optional – it’s a must!

 

Ready to streamline your service calls and installs? Explore the full range of wireless probe kits and see how Fieldpiece helps HVACR pros like you work easier, faster and better every day.

With the installation of A2L refrigerant systems gaining momentum, precision, documentation and professionalism matter more than ever. Fieldpiece is here to help you stay ahead with the Job Link® System App, a powerful tool designed to make installations and service calls more efficient, verifiable and customer-ready.

 

When it comes to A2L systems, thorough documentation isn’t just a best practice – it’s critical for compliance and verification to avoid costly callbacks. The Job Link® System App connects seamlessly with Fieldpiece wireless tools, empowering contractors, service managers and technicians to create a complete record of each job, right on the job site.

 

Why Documentation Matters More Than Ever

With A2L systems, following proper service and installation procedures is vital to maximize system efficiency and safety. Using the Job Link® System App to document critical details provides:

• Verification & Compliance: Instantly record pressure test results, vacuum measurements, decay test integrity, electrical checks, airflow measurements and superheat/subcooling.
• Fewer Callbacks: Eliminate guesswork and after service post-mortems. Your team can document each step as it’s completed, ensuring no detail is overlooked.
• Professionalism: Deliver a polished, complete report to your customers, giving them confidence in your work and reinforcing your company’s reputation for quality.

 

Best Practices: Document Every Critical Step

Some service steps previously only thought of as best practice are now requirements with A2L systems, like purging the system with nitrogen before cutting and brazing lines and conducting a leak and pressure test for a minimum of 60 minutes before charging. The Job Link® System App can track and record essential steps, including:

• Pressure Test: To verify the integrity of the line set.
• Evacuation: To pull a vacuum to the manufacturer-recommended micron level.
• Decay Test: To check the system’s ability to hold vacuum, ensuring no leaks.
• Electrical Check: To confirm proper volts, amps, and power to protect the system.
• Refrigerant Charge: To introduce and weigh in refrigerant accurately; critical for system efficiency.
• Airflow Check: To measure Delta T and static pressure to verify proper airflow.
• Superheat & Subcool Verification: To ensure the system is operating at manufacturer specifications.
• Complete Documentation: To back it all up with time-stamped, organized data that supports your tech, your business and your customer.

 

Support Your Techs, Your Business and Your Customers

For service managers, the Job Link® System App offers an easy way to ensure your team consistently follows best practices and provides accountability across all service calls. For owners, it protects your brand by reducing costly rework and complaints. For techs, it’s a safety net that provides proof that every job was done by the book.

 

Fieldpiece understands that staying competitive means being faster, smarter and more professional on every call. That’s why our Job Link® System App doesn’t just streamline your work – it takes it to a whole new level. As A2L systems become more common, the ability to verify and document every installation and service is no longer optional. It’s essential.

 

Stay Ahead with Fieldpiece

Visit fieldpiece.com to learn more about the Job Link® System App and how Fieldpiece tools are helping HVACR pros lead the way during the A2L transition and beyond.

2025 ushers in a new phase of the transition to A2L refrigerants for the HVACR industry. In case you missed it, the big change is a transition to A2L refrigerants with a low global warming potential (GWP) and phase down in production of hydrofluorocarbon (HFC) refrigerants with a high GWP. This change in refrigerant production, the new HVACR equipment required and resulting new regulations are being mandated by the EPA in execution of the AIM Act. Exactly how and when these new regulations impact you will vary based on the type of systems you install and service.

HFC Equipment Availability
As of December 31, 2024, manufacturers can no longer produce R-410A split systems, marking a major milestone in the HFC phase-down. In one year, December 31, 2025, will be the last day to install these systems. If you are doing a new installation of a residential or light commercial system you will need to plan accordingly.

For refrigeration professionals, the timelines differ slightly:

• Self-contained refrigeration units: Sales are allowed until January 1, 2028.
• Cold storage warehouses or supermarket refrigeration: Full system installations with HFC refrigerants will be prohibited starting Jan 1, 2026 and Jan 1, 2027, respectively.

The technology transition for variable refrigerant flow systems is moving on a slower schedule. There may be some relief from current implementation dates, but the EPA has not yet communicated those dates.

A2L Equipment & Install Changes
The transition to A2L refrigerants introduces important design and installation considerations:

• Due to A2L refrigerants’ mildly flammable nature, systems must include leak mitigation strategies such as automatic leak detection, shutdown mechanisms and blower fans to dissipate the refrigerant.
• A2L line sets will also require “Risk of Fire” labels and comply with local building codes. Consult your local building officials to understand all the new code requirements for A2L system installations to ensure compliance.
• Gray A2L cylinders have a red band or stripe to indicate the presence of the mildly flammable refrigerant. These cylinders require reverse-thread adapters, like the Fieldpiece A2L adapter extension, to differentiate them from HFC threads.

Recover, Recycle, Reclaim
Under the AIM act, the EPA outlines its goals to bolster the supply of HFC refrigerants in the United States by supporting recycling and reclamation, and mandating leak repair provisions for certain appliances. By 2028, the EPA is requiring reclaimed refrigerant be used for servicing existing equipment in addition to initial charges in certain systems for HVACR and heat pump equipment. This means that there is a need to recover and return HFC refrigerants to distribution. If you can reclaim and not mix refrigerants, you may receive money as well.

Documentation
Proper record-keeping remains essential when disposing of refrigerants. Ensure you log the following:

• Recovery location and date
• Type of refrigerant recovered
• Monthly totals of refrigerants recovered and sent for reclamation

For appliances containing 50+ pounds of HFC refrigerants, technicians must provide documentation of the amount added and any inspections performed to the equipment owner.

Stay Ahead of the A2L Transition
As everyone in the industry transitions to this new landscape, Fieldpiece is doing everything to ensure its tools are ready for the transition. Visit fieldpiece.com to see all the tools that are A2L-compatible. Fieldpiece will continue to support you every step of the way – helping you work easier, faster and better.

Why is it important to calibrate your combustion analyzer?

Calibration of your combustion analyzer is crucial to ensure accurate readings and ultimately, safe heating appliance operation. Combustion analyzers measure critical parameters like oxygen (O₂), carbon monoxide (CO), and combustion efficiency to help HVAC pros assess the performance of heating systems. Over time, sensors can drift due to exposure to gases, dust, and other contaminants, which can lead to inaccurate readings.

Without proper calibration, an analyzer might give false readings that could either falsely indicate that a system is operating within safe limits or fail to detect hazardous levels of CO. Inaccurate readings could also result in suboptimal efficiency adjustments, increased energy costs for customers or even cause equipment damage. In some extreme cases, incorrect calibration can lead to serious safety risks, including carbon monoxide poisoning. This is why regular calibration is not just a good idea—it’s essential.

Is combustion analyzer calibration mandated in certain regions?

Yes, in some cases, local jurisdictions have their own requirements for calibration frequency and documentation to comply with safety codes and emission standards. These rules can vary by country, state, or even municipality, and some locations may require proof of calibration to ensure that analyzers are providing accurate data, especially when used in industrial or commercial settings.

For example, certain safety authorities and organizations, like the Environmental Protection Agency (EPA) in the U.S. or other local building code authorities, may mandate that all combustion analyzers be calibrated annually and used in their certified state. It’s a good idea to check with your local HVAC or safety authority to determine what specific calibration requirements apply in your region.

How often do you need to calibrate your combustion analyzer?

The general recommendation is to calibrate your combustion analyzer annually, though some manufacturers might recommend more frequent calibration depending on use. Heavy usage in harsh environments, or frequent exposure to high concentrations of gases, may require more frequent calibration to maintain accuracy.

Annual calibration helps to ensure that the sensors remain accurate and that any drift in the readings is corrected. Fieldpiece combustion analyzers, like the CAT45 and CAT85, are equipped with long-life sensors, backed by a 4-year warranty, but you will still need to comply with regional calibration frequency requirements.

Does field-swapping the sensors mean it’s calibrated?

The answer to this will depend on the product manufacturer. In some cases, new sensors may need to be 3^rd party calibrated to ensure they align with the analyzer’s electronics and software. However, the Fieldpiece CAT45 and CAT85 field-replaceable sensors are plug-and-play, sealed and pre-calibrated for the device. If you don’t need a 3^rd party calibration certificate, replacing the sensors may be the fastest solution, but not the most economical.

Where can I get my Fieldpiece CAT45/CAT85 calibrated?

If you’re using a Fieldpiece CAT45 or CAT85 combustion analyzer, the best option is to send your analyzer to a Fieldpiece-authorized calibration center. Fieldpiece partners with certified facilities that are equipped to calibrate your analyzer according to factory standards. Centers will calibrate the O₂ sensor, the CO sensor, verify temperature measurements, update firmware if required and provide a certificate of calibration. You can locate authorized calibration centers through the Fieldpiece website or by contacting customer support (714-634-1844).

Regular calibration of your combustion analyzer is key to maintaining safety, accuracy, and efficiency when installing and servicing combustion heating appliances. By following the manufacturer’s guidelines and getting your analyzer calibrated annually, you’ll ensure reliable readings and avoid potential hazards. Whether you’re using the CAT45 or CAT85, keep your tools up to standard by using authorized services to maintain peak performance year-round!

Okay, we know soap bubbles are the traditional method for refrigerant leak detection on HVACR systems and they can be a very tried and true indicator. But when you need to pinpoint micro-leaks fast, an electronic detector with a higher sensitivity than bubbles can be the ticket.

The four main types of electronic leak detectors available to HVACR techs include: heated diode, corona discharge, infrared and ultrasonic. The following is a snapshot of how the different technologies work and the ins and outs of each to help you determine which is the best fit for your toolkit.

 

Heated Diode Detectors

With a heated diode detector, sampled air is heated to a high temperature, ionizing halogenated refrigerant gases. The resulting charged chlorine and fluorine ions, even in trace amounts, generate current through the diode which then triggers an alarm. Heated diodes detect leaks of HFC, CFC, HCFC, HFO, H2N2 (Tracer Gas) and other refrigerant blends. The Fieldpiece DR58 Heated Diode Leak Detector performs particularly well with R410A and sniffs refrigerant leaks as small as 0.03 oz/yr – that’s 20 times more sensitive than soap bubbles.

Heated diode detectors are not prone to false alarms, but their sensor life may be affected by excessive refrigerant exposure and contaminants like oil. The sensor should be checked regularly with a calibrated reference leak. It is recommended to replace to the Fieldpiece DR58 sensor after approximately 300 hours of use.

 

Corona Discharge Detectors

In a process similar to heated diode detectors, corona discharge detectors also react to a change in current flow from ionized gases. However, they pull sample air through an electrical field around an electrode. Gases are broken down by the electric arc (corona discharge), causing a change in electrode current which then signals a leak.

False alarms can occur with corona discharge detectors because they do not trigger on specific refrigerant compounds. Response times are slightly slower than heated diodes and corona sensor life can be as short as 24 hours of use.

 

Infrared Leak Detectors

Infrared detectors shine a beam of infrared (IR) waves through potentially contaminated air to detect and analyze trace amounts of refrigerant and signal a leak. Because light absorption in the IR spectrum is gas-specific, they are the least susceptible to false-positive alarms and considered highly accurate across all refrigerant types. Infrared detectors also have the edge with newer refrigerants that contain less chlorine and fluorine, the trigger for heated-diode sensors.

When considering the cost of ownership of a leak detector, the long life of the infrared sensor will factor in the equation. For example, the sensor life is approximately 10 years for the Fieldpiece DR82 Infrared Leak Detector.

 

Ultrasonic Leak Detectors

An ultrasonic leak detector is also known as a “listening detector.” When refrigerant escapes from a pressurized system, it creates tiny sound fluctuations in the form of high-frequency sound waves that the sensor picks up.

These detectors can hear very small leaks on high-pressure systems and their sensors last for a long time. However, when a system has low pressure, these detectors are not as accurate or effective. Ultrasonic leak detectors can also be affected by jobsite noise.

 

Techs have multiple options when looking for electronic leak detection tools, including heated diode, corona discharge, infrared, and ultrasonic. While each has its merits, the tool that’s right for you will depend on the refrigerants you work with now and expect to work with in the future, the accuracy desired, and your sensitivity to overall cost of ownership. An electronic leak detector is an investment that makes your job easier, so it’s worth the homework to figure out which one needs a spot in your tool bag!