Packaged rooftop units (RTUs) are the workhorses of the industry. Enduring rainstorms, snow showers, extreme heat and cold, and much more, the units provide conditioned comfort inside large enclosed areas season after season.

Even though the boxed bondservants take a licking and keep on ticking, the day will eventually come when the system finally reaches its breaking point. While it may cost a few more pennies initially, properly maintaining a rooftop unit will help ensure the device continues to provide peak performance, saving a consumer a collection of pennies in the long run.

Service Agreements

Due to their location, rooftop units may be difficult to reach. Long winters may leave the device covered in snow, and scorching summers may make the units too hot to handle. Even if technicians are able to access the units, correctly diagnosing or fixing problems poses an entirely different challenge.

To prevent these emergency situations, many contractors are encouraging facility managers to purchase service contracts. While these contracts may cost a bit more upfront, contractors insist the agreements ensure maintenance is performed properly, and on time.

“Much of our business is maintenance agreements on commercial or industrial refrigeration, HVAC, and controls,” said Bruce Boyd, owner, Rocky Mountain Mechanical Systems Inc., Denver. “These agreements are beneficial to our customers because it helps their heating and cooling system remain functional. Our technicians also benefit because it offers a bit of work for them during the slower months.”

Boyd said these agreements are especially important to his bigger customers whose business relies on operational commercial refrigeration.

“Our critical refrigeration customers have millions of dollars in products cooled by these refrigerators and these systems simply can’t go down,” he said. “While we can’t control Mother Nature, we do the best we can to ensure continuous operation through remote computer access and constant observation.”

Andrew Beeker, owner, Klondike Air, Costa Mesa, Calif. said service agreements serve as a great way to save money on an energy bill, and on out-of-pocket expenses.

“Service agreements provide several benefits as we won’t charge these customers for an additional service call, they get top priority service in case of a heat wave, and discounts are offered on parts and repairs,” he said.

System and maintenance costs should be projected and included in a consumer’s operating budget, said Rick Fenske, owner, Dynatek Ind. Inc., Woodstock, Ill.

“The average life of most systems, in general, is 15 to 20 years, depending on operating conditions,” said Fenske. “Poorly serviced systems, or those not serviced at all, will have more breakdowns and need replacements sooner than those that have been properly serviced.”

Stephanie Lammers, marketing representative, Jasper Heating and Cooling, Baton Rouge, La., said while service contracts at the company aren’t mandatory, they’re highly recommended.

“Service contracts are important due to the fact that they give the consumer a twice-a-year chance to catch a small issue before it becomes a large one. If a high voltage wire is loose, it can cause the amp draw on the system to be high, and in turn, lead to higher bills and shorten system life,” she said. “You would not drive a car without changing the oil or putting air in the tires. The same principle applies to a rooftop HVAC system.”

Whether or not a service agreement is signed should be the decision of the building owner, said Randy Koch, owner, Four Seasons HVAC, Ann Arbor, Mich.

“We actually feel better explaining the pros and cons of service contracts to customers and letting them decide. If they decide not to sign up for a contract, we just encourage them to be consistent in receiving regularly scheduled maintenance,” he said. “To us, given the economics of the last few years, it’s understandable that many customers choose not to be tied down to specific overhead agreements.”

Johnathan Youngs, owner, High Performance Heating and Air, Concord, Calif., said consumers should carefully examine contracts before signing on the dotted line.

“Maintenance contracts as a concept are fine. It’s how they’re usually implemented that makes them a sham. I can’t speak to all segments of the trade, but within the light commercial and residential segments, maintenance contracts are, locally and in my experience, not much more than a marketing tool.”

Maintenance Matters

While no specific maintenance schedule has been set in stone, many manufacturers offer maintenance guidelines for contractors.

“For heating and cooling products, the appropriate section should be inspected and cleaned at the beginning of each season. This will ensure not only that it operates properly, but that efficiency is maintained,” said Roxanne Scott, national product manager, Heat Controller. “If maintenance is not performed on a regular basis, efficiency is likely to suffer and capability may be compromised. When a system isn’t operating properly, the unit may cycle on and off more than usual, creating additional wear on components. Occupants of the building may complain of inadequate cooling. It’s always easier to clean and repair components, and to get replacement parts if needed, prior to seasonal peak demands.”

Skip Ernst, marketing manager, applied air products, Daikin McQuay said new technology is making maintenance easier than ever before.

“Smarter buildings are replacing physical maintenance with software,” he said. “Our Rebel system is easier to maintain because it includes extremely smart controls that diagnose problems with state-of-the-art remote control and monitoring, and automatically takes protective action.”

Following a proper maintenance plan has been proven to add longevity to an HVAC unit’s life-span. Maintenance also strengthens the unit’s performance leading to fewer breakdowns, more affordable repairs, greater efficiency, and — ultimately — energy and cost savings. The key is for contractors to effectively communicate these benefits to customers, and then follow through with regularly scheduled maintenance checks.

Sidebar: RTU Maintenance Tips

Regular maintenance is particularly important for all rooftop units as their remote location makes it harder to see and hear the signals that it’s time for a service call. Here are some universal tips for keeping rooftop units in peak operating condition:

Shut off all electrical power. Tag the disconnect before beginning service.

Inspect air filters and inlet screens. Clean or replace filters at the start of each cooling and heating season, at a minimum. Clean outdoor air inlet screens annually.

Inspect fan, housing, and motor. Make sure fans are properly centered in their housing. Check blades for excessive rusting and for the chips, cracks, and dirt buildup that cause noise and vibration. If motor bearings are not permanently lubricated, lubricate them every six months.

Inspect belts for wear, proper tension, and pulley alignment. Fan belts are a regular wear-and-tear item and should be replaced annually.

Inspect the heat exchanger. If the heat exchanger rusts or cracks, gases could contaminate the building’s air supply. Inspect burners, igniter, and combustion section (gas heat only). Popping, roaring noises, smoking, vibration, and flame rollout indicate ignition problems. Check the gas pressure and test for leaks.

Clean the coils. Dirty coils diminish heat transfer and increase operating temperatures and pressures. Wash and flush both sides of the coils. For best results, back flush toward the return-air section to remove foreign material. Be careful not to overwhelm the condensate pan.

Clean drainage. Clogged drain channels prevent water and other liquids from effectively moving out of the unit, which can in time cause damage to the unit and surrounding area.

Check the refrigerant charge. Before checking, run the unit for 15 minutes in the cooling mode to stabilize system pressure. If a substantial adjustment is indicated, check for refrigerant leaks or insufficient airflow across the coils.

Check for voltage imbalances. The Department of Energy recommends that voltage imbalances not exceed 1 percent — a greater imbalance can contribute to overheating and premature motor failure. Also check for loose wiring and connections, and corroded or frayed wires.

Conduct an amperage check. A high amperage draw could signal a mechanical problem, like worn bearings or worn rods, or it could indicate a refrigeration problem.

When you’re done, make sure all panels are fastened securely in place. Keep a bag of screws on hand to replace missing ones — use oversized screws for stripped holes.

Tips provided courtesy of Speedclean. For more information, visit

Publication date: 6/11/2012