HVAC Maintenance Checklist: Trane Thermostat Reset, Air Filters, and Ice Machine Cleaning

I've been on the purchasing side of a commercial building services company for six years. Six years of tracking every HVAC repair invoice, which works out to roughly $180,000 in cumulative spending. Here's what the paperwork taught me: most of that money wasn't for dramatic failures. It was for small problems that were quietly ignored until they became expensive.

So here's the checklist I hand to every site manager we hire. It takes about 90 minutes per location if you're systematic. It won't catch everything, and it's not a replacement for a licensed technician. But it catches the issues that generate the invoices I hate paying.

Step 1: Replace Air Filters on a Schedule, Not by Their Looks

Every tech I've talked to says the same thing: the air filter is the cheapest insurance your HVAC system has. I ignored it for the first two years and paid for it in blower motor repairs and reduced cooling efficiency.

The part most people miss is that a dirty filter doesn't die all at once. It makes the system work harder—higher static pressure, longer run cycles, bad heat transfer. On our 15-ton Trane package units, those clogged filters push the whole system into early retirement.

The fix is embarrassing in its simplicity:

• Write the date and MERV rating on the filter frame before sliding it in.
• Set a calendar reminder. 30 days for 1-inch fiberglass, 90 days for pleated filters. Trust me on this one—the eyeball test lies.
• If your system has pressure drop gauges, read them. If not, stick to the calendar.

ASHRAE Standard 62.1 recommends a minimum MERV 8 filter in most commercial buildings, which is what we use now. We standardized on a 90-day replacement cycle and our airflow-related callbacks dropped noticeably. I can't give you a clean percentage because I didn't track it meticulously back then, but the difference showed up in the invoice pile.

Step 2: Know the Trane Thermostat Reset Button Before You Call Anyone

This one has saved us more service call minimums than I want to admit. A lot of Trane thermostats freeze up in an odd way—the display goes blank, or it ignores temperature changes, or the schedule mode gets stuck and won't save anything.

Before you book a technician, try the reset procedure:

1. Use a paperclip or the tip of a pen to press and hold the reset button—it's usually in a small pinhole on the front or side of the unit—for 5 to 10 seconds.
2. Release it and wait. The screen will go through a boot sequence, sometimes going blank before coming back on.
3. Give it two or three minutes to reconnect with the HVAC equipment.
4. Reprogram your settings, or leave the defaults if you just want the system running.

Now the honesty part. Not every thermostat has a reset button, and a reset isn't a repair. If the same problem comes back every few days, the issue is probably wiring or the equipment itself, not the thermostat. That's when you call someone. There's a difference between a hiccup and a symptom, and learning to tell them apart is what this whole checklist is about.

Step 3: Watch the Weak Spots on a 15-Ton Trane Package Unit

These units are workhorses—we run two 15-ton Trane package units and they handle more than half of our cooling load. The purchase cost isn't the problem. The problem is the maintenance invoices that sneak up on them.

Condenser coil cleaning is the one vendor always wants to upsell, and it's actually worth doing. When the coil fins pack with dirt, head pressure climbs and the compressor draws more current. Compressor failure on a 15-ton unit means a four-figure replacement. We clean coils twice a year—spring and fall—with a coil cleaner and a garden hose. About $40 in materials and an hour of labor.

Also check the supply fan belt tension quarterly, especially before peak season. A loose belt slips, the motor overheats, and if I remember correctly, the spec is roughly half an inch of flex at the midpoint of the belt span. Not much. If nobody on your team is comfortable on a roof, pay for a semiannual preventive maintenance visit. That's not waste—that's buying certainty.

We almost switched maintenance contractors once because one firm came in 20% cheaper. The spreadsheet said it was a no-brainer. But something about their reference calls felt off—too scripted, too uniform. We stuck with our existing vendor. A year later, a site manager at another building told me that cheap contractor's inspections were famously shallow. The math would have gone sideways on us.

Step 4: Clean the Ice Machine Monthly (Yes, You Actually Have To)

This is the step everyone skips, and I have the inspection notice to prove it. Two years ago, a routine food safety audit flagged our break room ice machine. The issue was biofilm—a thin, slippery film on the inside of the bin. You can't see it if you're not looking for it, but it's there.

Here's how to clean an ice machine properly:

1. Turn the machine off. Remove the bin door and the ice scoop.
2. Empty the bin. Do not mix new ice in with old—the first batch after cleaning gets discarded anyway.
3. Remove the vent panels and drain any standing water from the reservoir.
4. Mix an approved ice machine cleaner with water according to the label directions. Never pour concentrated cleaner directly onto the bin surfaces.
5. Wipe down the evaporator plate, bin walls, door, and gasket with a soft cloth. No wire brushes—they scratch the plastic and give bacteria places to hide.
6. Rinse thoroughly. Then rinse again. Residual cleaner affects the taste of the ice and can be a health code issue on its own.
7. Let everything air dry before reassembling and restarting.
8. Throw away the first batch of ice produced after the cleaning cycle.

Commercial ice machines are covered under NSF/ANSI Standard 12, and under the FDA Food Code, an ice machine is a food contact surface. If you're serving food or drinks to the public, this is not optional. We now do this on the first Monday of every month and it's just on the calendar, done.

Step 5: Descale the Tankless Water Heater Before It Gets Expensive

The tankless hot water heater is the other overlooked piece of equipment on our properties. It reads as low-maintenance because there's no tank to rust, but hard water slowly coats the heat exchanger with scale. When that heat exchanger fails, you're looking at a serious repair—or a full replacement.

We flush ours every 6 to 12 months depending on water hardness. The general process: shut off the gas and water supply, connect a transfer pump to the service ports, circulate a descaling solution until it runs clear, then flush through with clean water. Exact steps vary by brand and model, so check the manual. I'm not going to recite it from memory because they genuinely differ.

The cost here is about $60 in pump rental and descaling solution. The cost of ignoring it is a failed heat exchanger at $2,000 or more. One caution: I can only speak to our situation. If you're on well water or your water tests above 10 grains of hardness, your flush interval should be shorter. Get a water test before you decide you're fine.

What Most People Get Wrong

The biggest mistake is skipping a step because the equipment looks fine. Visual inspection only catches maybe half of the problem. The ice machine looked perfectly clean until the audit. The air filter looked okay until we measured static pressure across it.

The second mistake is trying to turn a 15-ton package unit into a DIY project. There's a clear line between routine maintenance and a real repair. I'm not a technician and I've stopped pretending to be one. The vendors who are honest about that boundary get our bigger contracts. One of them once told us "this isn't our strength—here's who does it better" for a specialized refrigeration job, and that honesty earned them our trust for everything else. I'd rather work with a specialist who knows their limits than a generalist who overpromises.

The most expensive service call I ever paid for was the one where nothing was actually wrong—just a thermostat that needed a reset and a filter that needed replacing.

When to Skip the Checklist and Call a Professional

If any of these show up, stop reading and make the call:

• Recurring breaker trips on the package unit—a thermostat reset won't fix that.
• Refrigerant leaks, whistling lines, or frost building up on the suction line.
• Oil stains on or around the compressor.
• Any work involving gas lines, combustion venting, or heat exchanger integrity.

This checklist is what I use. It's not the whole story, and your situation will be different—your climate, water hardness, roof access, and your team's comfort level all change the equation. But if you track your maintenance costs for the next year, I think you'll see what I saw: expensive emergencies are almost always preceded by cheap maintenance that just never got done.