The call I almost didn't take
It was a Tuesday in late July 2019, and I was about to leave for a steakhouse compressor hunt. The phone rang. The caller was the owner of a two-location bubble tea shop a few blocks away. Their countertop ice maker had stopped making ice, and the backup fridge was running warm. The ticket in my book said “restaurant ice maker repair.” I almost told him I couldn't come until Friday.
I remember thinking: small shop, small ticket, probably just a clogged water valve. I didn't say that to him, but I felt it. When I first started running my own service van, I assumed big commercial accounts were the ones that mattered. Small restaurants and bars were just fill-in work.
That assumption cost me about $780 and most of my professional confidence.
R290 isn't just “the flammable one”
By July 2019, R290 was all over small commercial refrigeration. A bar shop freezer, an under-counter bottle cooler, a bar bubble tea ice maker—if it was new and compact, there was a good chance it used R290. I knew it was propane. I also thought knowing that was enough.
The bubble tea R290 refrigerant system on that machine wasn't exotic. It was a small hermetic system with a tiny charge. I want to say the charge was less than 100 grams, but don't quote me on the exact spec because that model is long gone. The point is: it's easy to overcharge a system like that without realizing it.
According to ASHRAE Standard 34, R290 is classified A3—low toxicity, higher flammability. ASHRAE Standard 15 and UL 60335-2-89 set parts of the safety framework for commercial refrigeration. I knew the alphabet soup, but I didn't connect it to the little ice maker behind a bubble tea counter. I do now.
What happened when I tried to top it off
The owner told me the ice maker had been getting weaker for a week. I found low pressures and a data plate that said R290. Then I did the thing I now tell every tech never to do: I added refrigerant to a partially charged system without finding the leak.
I used a bulk cylinder and my “experience.” No scale. No leak check. I was going by the frost line on the suction line, which is already a bad idea on fixed-orifice systems. The unit ran well for about two hours—or rather, about two hours and forty-five minutes. Then the compressor started making a low, expensive knock.
The owner called me that evening. By the time I got there, the compressor had failed. I had turned a small leak into a compressor replacement.
We replaced the compressor, the filter drier, and the leaking Schrader valve. Total cost: about $780 in parts and labor, plus a courier fee for the compressor. I refunded my original service call. No one got hurt (thankfully), but that was luck, not skill.
It's not enough to know R290 is flammable. You have to respect the service rules around it—or you're gambling with somebody else's business.
The after-sale R290 refrigerant checklist I keep in my van
After that failure, I built a checklist. It's not an official document, but it keeps me from repeating my own stupid mistakes.
- Verify the refrigerant on the nameplate before connecting anything.
- Use a hydrocarbon-compatible leak detector. Many old electronic sniffers won't catch R290 reliably.
- Recover the remaining charge before opening the system. Never release it to atmosphere.
- Find and fix the leak. Topping off a flammable system is not a repair.
- Weigh the charge to the manufacturer's spec. With small charges, even 10 grams makes a difference.
- Work in a ventilated area with no ignition sources nearby.
The after-sale R290 refrigerant reality is that this checklist is the boring but vital part of the job. Most service failures I see are not exotic. They're from techs who didn't clean the condenser or didn't leak-check and assumed the gas was just “low.”
The bar shop freezer case came a few months later. A tavern owner had paid someone to add R290 to a freezer three times in one year. The fix wasn't refrigerant at all. The condenser coil was half clogged with grease and dust, and the fan blade was loose. I cleaned it, replaced the fan motor, and that unit has run ever since.
The anti-rust hotel refrigeration lesson
The next year, a small hotel taught me the second big lesson. Two reach-in refrigerator units kept losing temperature, and a previous tech had quoted two compressor replacements. That seemed wrong to me, so I went through the system carefully.
The units were four blocks from the ocean. Salt air, humidity, and cleaning chemicals had rusted the condenser coils from the outside. I found pinhole leaks in three different spots. The compressors were fine. New compressors would have been a $2,800 mistake.
What the hotel needed was anti-rust hotel refrigeration: coated coils, corrosion-resistant cabinets, and fans built for that environment. We swapped to an epoxy-coated model and did the install right. Those units have run without the same failure since.
Small accounts taught me the biggest lessons
The technical part of this story is about R290, but the bigger part is about attention. I almost skipped that bubble tea shop. I could have lost that account forever. Instead, two years later, that owner had six locations—and we service all of them.
There's something satisfying about that. Not just the growth, but the trust. Small doesn't mean unimportant—it means potential.
Now, when I start a job, I check my assumptions at the door. Whether it's a restaurant ice maker repair or an anti-rust hotel refrigeration install, I ask the same questions: What is this unit telling me? What am I missing? Am I respecting the refrigerant and the customer?
As of this writing (March 2025), the standards landscape for R290 is still evolving. I always check the current version of UL 60335-2-89 and ASHRAE 15 before doing work on unfamiliar equipment. I'm not a regulator. I'm a repair guy who learned the hard way that the smallest jobs deserve your full brain.