Episode 405. 5 Things To Check Before Needlessly Replacing a Compressor
The Refrigeration Mentor Podcast
Release Date: 06/18/2026
Episode 420. CO2 Oil Management: Preventing Compressor Failures with Jonas Linnemann of Vitalis (Part 1)
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at This is the first of a 2-part episode in our “CO2 Unfiltered” series covering what causes compressor failures and how to prevent them, featuring Jonas Linnemann, Vice President of Technology at Vitalis. Jonas explains why oil return is more challenging in CO2, and covers topics like primary vs secondary oil circuits, separator efficiency and compressor oil carryover. He also shares practical service and maintenance tips that will help refrigeration techs prevent recurring compressor failures. In this...
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Episode 419. Daikin 2-Stage CO2 Condensing Unit Servicing and Troubleshooting with Massimo Pellizzari (Part 2)
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at This is the second of a 2-part episode in our “CO2 Unfiltered” series where we’re joined by Massimo Pellizzari, Senior Commissioning Engineer at Daikin, for an in-depth look at Daikin’s two-stage CO2 condensing units (link to Part 1 below). Here, we cover wiring, as well as troubleshooting via the onboard display and buttons, alarm code structure, and conditions like wet operation, high-pressure switch trips, and how the controller can detect overcharge or refrigerant shortage. This 2-part episode is...
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Episode 418. Daikin 2-Stage CO2 Condensing Unit Servicing and Troubleshooting with Massimo Pellizzari (Part 1)
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at This is the first of a 2-part episode in our “CO2 Unfiltered” series where we’re joined by Massimo Pellizzari, Senior Commissioning Engineer at Daikin, for an in-depth look at Daikin’s two-stage CO2 condensing units. Massimo explains the design philosophy behind these systems, how they differ from traditional refrigeration equipment and the best practices for installation, commissioning, evacuation, charging and servicing. Whether you're new to CO2 or looking to sharpen your troubleshooting skills, this...
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Episode 417. CO2 Rack Troubleshooting & Fine-Tuning: Lessons from the Refrigeration Mentor Community
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at This episode includes highlights from a recent live Refrigeration Mentor Community meetup where we covered real-world CO2 rack issues, system tuning, troubleshooting, and startup strategies, sharing practical techniques we've learned in the field. We covered gas cooler fan tuning, transcritical operation, oil separator maintenance and service valve tips. This meetup featured experienced CO2 technicians Patrick Gregory, Noah Walker, Andrew Freeburg, Billy Carlson and others sharing valuable insights that can help...
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Episode 416. CO2 Liquid Overfeed Pump Problems
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at This episode is the first of a 10-part “CO2 Unfiltered” series, where we’re joined by Ernesto Rodriguez to discuss hermetic CO2 pumps. Ernesto has decades of practical knowledge to help technicians understand how CO2 pumps really work and why so many failures can be prevented through proper design and installation. Here, we cover pump selection and sizing, and troubleshooting, including how to recognize cavitation and flash gas, avoid common piping mistakes, optimize pump performance, and commission CO2...
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Episode 415. Advanced Copper and Copper Alloy Brazing with Mike Belanger
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at In this episode, we’re teaching advanced brazing and soldering skills for copper piping with Mike Belanger from the Copper Development Association. Mike teaches soldering and brazing fundamentals: proper cutting, reaming, cleaning, minimal fluxing, full insertion, correct heat application. This session also covers vital tips for how to properly braze starting with the foundations of what refrigeration techs need to know and how to make better joints and prevent leaks. In this episode, we discuss:...
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Episode 414. Breaking the Stigma and Learning to Love CO2
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at In this episode, we’re talking about how techs are breaking the common fears and apprehensions around CO2 refrigeration as it grows and systems become more controls-heavy. I’ll share my own early intimidation with CO2, including having to call for senior help. We’ll discuss how learning critical CO2 refrigeration pillars like P&IDs, wiring diagrams, I/O schedules, and refrigeration schedules will help techs get more comfortable with CO2 and learn faster. In this episode, we cover: (00:48) My First...
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Episode 413. My 4-Pillar Framework to Learn CO2 Refrigeration Faster
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at In this episode, I’m breaking down my 4-pillar framework used in my supermarket and CO2 refrigeration training programs. These pillars include understanding system design, electrical, the input and output (I/O) schedule, and the refrigeration legend/schedule. Building your refrigeration knowledge on these pillars is critical for technicians to identify what’s normal, verify issues systematically, and solve harder problems faster. In this episode, we cover: 01:52 The 4-Pillar Refrigeration Mentor...
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Episode 412. Live Group Troubleshooting: Working Through Issues Fellow Techs (Community Meetup Replay)
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at This episode is a replay of a recent Refrigeration Mentor Community Meetup where we helped fellow techs with some technical CO2 refrigeration troubleshooting. The live group discussed a problematic CO2 store with high superheat, recurring low-temp oil issues, phase-loss/current-imbalance alarm and others. You’ll hear solutions, tips and advice from the fellow techs on the call, including Mikaela Law, Patrick Gregory, Andrew Freeburg, Billy Carlson, Noah Walker, and others. Interested in joining the next meetup?...
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Episode 411. Fast-Tracking as a New Supermarket Refrigeration Tech with Jacob Decker
The Refrigeration Mentor Podcast
Learn more about Refrigeration Mentor Customized Technical Training Programs at In this conversation, I sit down with Supermarket Refrigeration Technician Jacob Decker to discuss how newer technicians can land opportunities and gain experience faster. Jacob shares how he moved from residential work and tech school into commercial refrigeration and a full time career with Walmart through connections, overcoming fears, learning form mistakes, and how he benefited from mentorship and structured training. We also cover common challenges for new techs, plus practical habits to build that will...
info_outlineLearn more about Refrigeration Mentor Customized Technical Training Programs at www.refrigerationmentor.com/courses
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In this episode, I’m outlining five things refrigeration techs need to check before replacing a compressor to avoid an unnecessessary change out. Between 30-40% of swapped compressors are found to have no real issue, and these checks will help technicians uncover root-cause issues and potentially avoid costly and time-consuming work that might not be needed. This episode details the five checks: oil level and oil management, compressor superheat, electrical health, operating conditions, and controller/sensor accuracy. We also cover key readings and how to better understand failure modes and prevent repeat failures.
In this episode, we discuss:
(00:48) How to Avoid Replacing Good Compressors
(03:16) Check 1: Oil Management
(04:27) Check 2: Compressor Superheat
(06:13) Check 3: Electrical Health
(07:14) Check 4: Operating Conditions
(08:19) Check 5: Controllers and Sensors
(09:56) Inspecting a Failed Compressor
(12:14) Documentation and Preventing Repeated Failures
Helpful Links & Resources:
FREE GUIDE: System and Compressor Troubleshooting Guide
Episode 115: Understanding Compressors: What You Need To Know
Episode 329. The Ins & Outs of Compressors
Episode 388. Step-By-Step Compressor Change Out (Service Call Recap) with Andrew Freeburg