Rant: The day our walk-in cooler died during a full Saturday service

Last weekend in Portland our walk-in just gave up around 5pm, right when we had 40 covers on the books and a full prep list. The compressor sounded like a dying lawnmower for a couple days, but I ignored it because we were slammed. By 7pm the temp hit 60F and I had to move everything into the basement fridge and two ice chests we borrowed from the bar next door. We lost about $300 in fish and dairy before I could re-route orders to the local supplier. Ended up calling an HVAC guy at 9pm who found a bad relay switch, cost me $450 for a part that probably needed replacing years ago. Any other kitchen folks here learned the hard way that your walk-in tells you it's sick way before it dies? What's your cutoff for calling a repair tech vs. trying to limp it through the week?