Evaporator coil replacement in Kalamazoo, MI

The evaporator coil sits in a cased box on top of your furnace, or inside the air handler on a heat pump system. Warm house air passes over its cold tubes and fins, giving up heat and moisture before the blower sends it back through the ducts. When the coil leaks or clogs, the whole system loses its ability to cool, no matter how well the outdoor unit runs.

Our technicians replace coils with models matched to your outdoor unit's capacity and refrigerant type, so the system keeps its rated performance. We confirm the leak is in the coil before recommending replacement, and we check the drain pan, the cabinet fit and the furnace blower at the same time. You get a firm price before work starts. Call (269) 360-5258, answered 24/7.

Signs you need evaporator coil replacement

Why evaporator coils fail

Corrosion is the leading cause of coil leaks in Michigan homes. Copper coils can develop formicary corrosion, a branching pattern of tiny pinholes that starts on the outside of the tube. Aluminum coils resist that type but can corrode from airborne chemicals and moisture in damp basements. Either way, the leaks are small, slow and often spread across the coil over a few seasons.

Coils also fail from physical damage. A coil cabinet that was not sealed lets dust pack the fins, and a cleaning attempt with harsh chemicals or a stiff brush can tear tubes. On older systems, the drain pan beneath the coil rusts or cracks, letting water spill onto the furnace. We look at all of these before recommending a replacement.

Matching the new coil to your system

A replacement coil needs to match the outdoor unit's capacity, the refrigerant it uses and its metering device, whether that is a fixed orifice or a thermal expansion valve. It also needs to fit the furnace cabinet and the plenum above it. An undersized or mismatched coil can freeze, cause high head pressure in the outdoor unit and shorten compressor life.

Coils come in cased and uncased versions and in A-shaped or slab designs. We measure the furnace opening, the plenum height and the duct transition before ordering. When an exact match is not available, we choose a coil the outdoor unit manufacturer lists as compatible. If the system is old enough that a match is hard to find, we discuss replacing the full system.

• Matched capacity and refrigerant type
• Correct metering device for the outdoor unit
• Cabinet width and height for the furnace
• New drain pan and secondary drain or float switch

What the replacement involves

We start by recovering the refrigerant from the system into a recovery cylinder. The old coil is cut out of the line set, the plenum or cabinet panel is removed, and the coil slides out. The new coil goes in, and we braze the connections with a nitrogen purge flowing through the tubing so no scale forms inside. Sealed panels go back on to keep air from bypassing the coil.

With the lines closed, we pressure-test with nitrogen and pull the system into a deep vacuum, watching the micron gauge to confirm it holds. A new filter drier is installed on the liquid line. Then the system is charged by weight and fine-tuned by superheat or subcooling. Finally, we rebuild the condensate trap, test the overflow float switch and run the system.

Coil replacement or a new system

The age of the outdoor unit drives the decision. On a system under 8 to 10 years old, the coil may be covered under the manufacturer warranty for parts, leaving labor and refrigerant as the main cost. On a system past 12 to 15 years, spending on a coil means putting new parts on an old compressor that may not last much longer.

We price both options during the same visit so you can compare them directly. If the outdoor unit is still in good health and uses a refrigerant that is easy to source, coil replacement can add years of service. If the furnace is aging too, a combined furnace and AC replacement may cost less over the next decade than fixing pieces one at a time.

How a evaporator coil replacement visit works

1. Call with your leak findingsIf another visit already found the leak, tell us. Otherwise we confirm it is in the coil before quoting a replacement.
2. Measurements and matchThe technician records model numbers, measures the cabinet and plenum and checks warranty status on the coil.
3. Price and orderYou approve a firm price. We order the matched coil and set an install date, usually within a few days.
4. Coil swap and brazingRefrigerant is recovered, the old coil comes out, and the new coil is installed and brazed with a nitrogen purge.
5. Vacuum, charge and testWe pressure-test, evacuate, charge to specification and run the system to confirm cooling and drainage.