Lennox Mini-Split Installation Nationwide

Lennox Mini-Split Installation: The Marietta Owner’s Guide

A Lennox mini-split installation in Marietta typically runs $3,800 – $6,500 installed for a single-zone system, and $6,500 – $11,000 for a multi-zone setup covering two to four rooms. We stock Lennox-compatible mounting hardware, line sets, and electrical components on our trucks, so most single-zone installs in Cobb County are completed same-day once we’ve confirmed your model and layout. The way most homeowners discover they need us is simple: the indoor unit stops cooling, starts dripping, or the outdoor unit runs constantly without the room ever reaching the temperature on the remote.

Call (762) 240-5599

If that sounds like your week, you’re in the right place. Victor Mancini and our crew have installed and serviced Lennox mini-splits across Marietta for years, from East Cobb ranch homes to new additions near the Square. We know these units well enough to tell you what’s actually wrong before we touch a wrench.

Which Lennox Models This Applies To

We install and service the full Lennox mini-split line, including the MLA and MPB single-zone series, the MWMA and MPB multi-zone units, and the newer Lennox Elite and Signature mini-split systems. The key compatibility point most homeowners miss: your indoor wall unit and outdoor condenser must be matched by capacity, not just by brand. A 9,000 BTU indoor head paired with a 12,000 BTU outdoor unit will short-cycle and wear out early. When we quote a Marietta install, we check the model numbers on both units before pricing anything.

Cold Harbour Heating and Air Marietta is an independent service provider. We are not affiliated with Lennox, but our techs are factory-trained on their mini-split systems and we install genuine Lennox components when they matter most: control boards, inverter boards, and fan motors. For line sets, mounting brackets, and condensate pumps, we’ll often recommend quality aftermarket equivalents that meet or exceed spec and cost 20 – 30% less. You’ll see the difference on the written quote before any work begins.

Signs Your Lennox Mini-Split Installation Is Failing

• Water dripping from the indoor unit onto your floor. This usually means the condensate drain line is clogged or the drain pan has cracked. In Marietta’s humid summers, a mini-split can pull two to three gallons of water out of the air daily, so a small clog becomes a puddle fast.
• The outdoor unit runs but the indoor fan doesn’t blow cold air. This points to a failed refrigerant charge, a bad inverter board, or a communication error between the two units. Lennox mini-splits use a communicating system, so a loose wire at the terminal block can shut down the whole thing.
• The system short-cycles: starts, runs five minutes, shuts off, repeats. A mismatched indoor/outdoor capacity, a dirty coil, or a failing thermistor will cause this. We see it regularly in Marietta homes where a previous installer used whatever unit was in stock instead of what the room actually needed.
• Ice forming on the copper line set outside. This means low refrigerant or restricted airflow. Running it this way for even a few weeks will kill the compressor, and compressor replacement on a mini-split often costs more than a new outdoor unit.
• Error codes flashing on the remote or a blinking LED on the indoor unit. Lennox mini-splits log fault codes that tell us exactly which sensor or board failed. Snap a photo of the code before you call, and we’ll likely have the part on the truck when we arrive.

Replacement Cost & What’s Included

Most Lennox mini-split installations in Marietta land between $3,800 and $11,000 depending on the number of zones and the complexity of the line set run. A simple single-zone replacement where we reuse the existing line set and electrical usually runs $3,800 – $5,000. Adding a second indoor head or running new copper lines through an attic or crawlspace pushes the job to the top of that range. You’ll get the written price before we start, and that number won’t change at the door. That’s The Kingswell Way, and it applies to every job we do in Cobb County.

Every Lennox mini-split we install includes the wall bracket or floor stand, line set, communication wire, condensate drain, and the startup sequence that calibrates the system. The labor is covered by our 365-Day Done Right Promise: if anything we installed fails within a year, we come back and fix it at no charge, with that guarantee on paper before we leave.

Here’s what a typical single-zone Lennox mini-split install in Marietta looks like line by line:

• Indoor wall unit and outdoor condenser: $2,200 – $3,400
• Line set, wire, and mounting hardware: $400 – $700
• Labor and commissioning: $1,200 – $1,900
• Total: $3,800 – $6,000

DIY or Call Us?

This is one part where the safety concern is real, and it’s not something to brush past. A mini-split installation involves high-voltage electrical connections, refrigerant under pressure, and drilling through your exterior wall where plumbing and wiring may hide. Getting any of those wrong causes more than a broken unit. It causes a fire risk or a refrigerant leak, and both are problems you don’t want to discover at 2 a.m. in a Marietta July.

What you can safely check yourself: confirm the breaker is on, clean the washable filters in the indoor head, and make sure furniture isn’t blocking airflow. What you should not do: open the outdoor unit, touch the terminal block, or try to recharge refrigerant. That’s a job for a trained tech with the right gauges and recovery equipment. Call us at (762) 240-5599 and tell us what the system is doing. We’ll give you a straight answer and a written price.

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