The Ice Machine

Ice machines are high profile. When one goes down, people take it personally. The old folks at Windmill Manor? If they lose their ice machine in the cafeteria? They lose their minds. Believe me. The kitchen manager at Blackstone? He has to personally make ice runs to Hy Vee when his machine is down. Six hundred pounds a day. Buff’s Game Day in Solon? They need ice if they’re going to sell alcohol. Nobody says, “Fuck it. Just give me a G-n-T straight up. Warm. No. Really. That’s how I want it.”

I had three ice machine calls in one morning last week. One at Blackstone, one at Pleasant Valley Golf Course, and one at Hilltop Tavern, the oldest bar in Iowa City. The first one, Blackstone, was a callback. I had replaced the ice thickness sensor on their Manitowok two days prior. It ran for a few cycles, and then, not long after I drove away, it quit again.

What Manitowok does is, they have a sensor that emits a high frequency sound wave at the evaporator plate. As ice is formed and the gap between the sensor and the ice decreases, the frequency feedback changes. At a certain feedback frequency, harvest mode is initiated. But this one was constantly at that higher frequency and it always wanted to harvest.

I went through the steps by myself — checking the DC signal from the board, checking the frequency on the service menu, scratching the mic to see if the signal changed — and then I went through the same steps with technical support over the phone. The guy from tech support said unequivocally that I had a bad ice thickness sensor.

“But I just replaced it,” I said. “You think it’s bad from the factory?”

“It happens,” he said.

“How do you know it’s not the board?” I said.

“We’re getting a perfect voltage from the board,” he said. “The voltage couldn’t be better from the board. It’s not the board.”

It always makes me feel better when someone in authority is unequivocal about stuff like this. I feel armed with The Word. I can tell the customer that the tech support guy direct from whatever factory told me whatever whatever, and I tell myself that his word sort of relieves me from the responsibility of whatever might happen once I do whatever he told me to do. Even though that never really does protect me from anything. Let’s be honest.

Regardless, I couldn’t let this one go. First, I didn’t want to wait two days for the same part to arrive again. Second, something didn’t seem right about the diagnosis. I removed the control board from its nylon clips, yanked off all the wires, turned it around and checked the backside. Sometimes you can find a solder joint that has melted or somehow come loose. But this one looked pristine. I removed the ice sensor and inspected it. No cracks. I shook it. No water inside. I checked the wire harness and found a tiny strand of ground wire that was reaching across and shorting against one of the DC wires. I cut the strand, reinstalled the sensor, and tried it again. It worked. For two days. Then I got another callback.

So I replaced the fucking ice thickness probe again just like the fucking tech support guy told me to fucking do.

But that didn’t work. The board still thought it should try to go into harvest mode the minute it went into freeze mode. And if it’s ice you want, that’s no good. So I did the thing any mechanic does when they’re at the end of their tether. I ordered a new control board.

Troubleshooting and then repairing a piece of equipment isn’t for people of a mystical bent. You don’t want to be asking the Great Spirit for guidance. You don’t want to be drawing tarot cards in an attempt to determine whether this machine is a five of pentacles this week or a nine of swords. That shit doesn’t flush. The idea is you rid the machine of mystery. Clear the mystery away. There can be no mystery. Because with mystery comes uncertainty. And with uncertainty comes callbacks. And callbacks are the worst thing that can happen to a mechanic.

Luckily, I enjoy solving mysteries. It makes me feel important.

That said, ordering a control board is a capitulation to the great mystery of the universe. Nobody knows exactly what happens inside those things. Especially us mechanics. What we’re saying when we finally throw up our hands and throw down $1,000 for a board is, “I don’t know exactly what the problem is in there. All I know is I don’t think this thing is doing what it’s supposed to do. I really don’t. I $1,000 don’t.”

The ice machine worked fine once I replaced the board.

That was Monday. Now it’s Sunday. The machine is still making ice. Which means the board was the problem.

I guess.

Not sure why exactly.

Anyway, the machine will keep on working until something else goes wrong with it. And when that happens, I’ll be there. God willing. To strip away whatever stink of mystery hovers about that thing. If I can. And if I can’t? I’ll order another board.