Lennox Heat Pump Service Nationwide

Lennox Heat Pump Service: The Marietta Owner’s Guide

We stock, install, and warranty Lennox heat pump parts across Marietta, and most common repairs run between $150 and $650 with parts and labor included. If your Lennox heat pump is making a sound it never made before, running constantly without satisfying the thermostat, or blowing air that feels lukewarm in the middle of a Cobb County summer, you’re probably looking at a failed compressor, reversing valve, defrost control board, or capacitor. This page lays out what those parts cost, which Lennox models they fit, how we match OEM and quality aftermarket pieces, and when you can expect us on your doorstep in Marietta.

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Which Lennox Models This Applies To

Lennox heat pumps share a common architecture across several residential lines, but the part numbers change depending on the series and era. If you have an XP14, XP16, XP17, XP20, XP21, or the newer Elite and Signature series units, the compressor, reversing valve, and defrost sensors we install are matched by your unit’s model plate – the metal tag usually located on the outside unit’s corner panel. That plate carries a model number starting with “XP” or “SL” or “EL” and a serial number that tells us exactly which revision of the part came from the factory. Getting that plate right matters because Lennox made mid-series changes: an XP16 built in 2014 and one built in 2019 use different defrost control boards even though the marketing name is identical.

On the OEM versus aftermarket question, we carry both and we’re straight about when each makes sense. For compressors and reversing valves we recommend genuine Lennox or Copeland-sourced OEM parts, because those components operate under refrigerant pressure and heat stress that cheap generics don’t survive in a Marietta attic or on a west-facing pad in Indian Hills. For capacitors, contactors, and defrost sensors, quality aftermarket replacements from suppliers we’ve vetted over 20 years match OEM specs at a better price, and we’ll tell you the brand and the spec before we install anything. Cold Harbour Heating and Air Marietta is an independent service provider, not a Lennox dealer or factory affiliate – which means our recommendation on every part is based on what will hold up, not what a manufacturer’s program tells us to push.

Signs Your Lennox Heat Pump Service Is Failing

• The outdoor unit hums but the fan won’t turn. Almost always a failed dual-run capacitor – a $35 to $80 part that stores the starting voltage for the compressor and fan motor. We replace these frequently in Marietta, especially after July heat waves that cook capacitors until they swell and leak.
• The heat pump runs in defrost mode when it shouldn’t. On Lennox units, this usually points to a failed defrost thermostat or defrost control board. The board is cycling the system into a 10-minute defrost even when the coil has no frost, which kills your cooling performance and spikes the power bill.
• Warm air in cooling mode during a Marietta afternoon. If the compressor is running but the air at the register is 65°F instead of 55°F, the reversing valve may be stuck partway. A stuck reversing valve blends hot gas and cool refrigerant, and on Lennox units it often follows a refrigerant leak or sludge from a compressor that’s beginning to fail.
• The system short-cycles – on for three minutes, off for three minutes. A failing compressor overload sensor or a bad start capacitor will kick the unit off before it completes a cycle. This is the pattern Victor Mancini sees most often right before a total compressor failure, and it’s a repair that gets cheaper the earlier we catch it.
• Frost or ice on the outdoor coil in cooling season. In Georgia humidity, evaporator ice usually means low refrigerant from a slow leak or a failed defrost sensor on the outdoor coil. Letting this ride turns a $280 leak repair into a $900 coil replacement, so we treat it as a same-day diagnostic whenever possible.

Replacement Cost & What’s Included

Most Lennox heat pump service repairs in Marietta fall between $150 and $650 installed, and here’s what moves the number within that range. A dual-run capacitor replacement – one of our most booked Lennox calls – typically runs $150 to $280, part and labor included. A defrost control board runs $250 to $400 depending on whether your unit is a standard XP series or a communicating Signature model. Compressor replacements on Lennox heat pumps run $750 to $1,800 depending on the compressor size and whether we need to flush and recharge the refrigerant circuit, and reversing valves fall in a similar band when compressor replacement is required. Every written price includes the diagnostic time, the part, the installation labor, refrigerant recovery and recharge where applicable, and a written 365-day guarantee on the repair. You get the price in your hand before a single tool comes out of the truck – that’s the Kingswell Way, and it’s been our operating rule since 2003.

DIY or Call Us?

There are a few things you can safely check before you pick up the phone: confirm the thermostat is set to “cool” not “fan only,” look at the breakers for the air handler and outdoor unit, and check that the condensate drain hasn’t tripped a float switch. That’s about where the safe list ends. A Lennox heat pump contains a 240-volt electrical circuit, refrigerant under high pressure, and a compressor that stores capacitor charge even after power is disconnected. A wrong guess can turn a $180 service call into a blown control board or a refrigerant burn, not to mention the personal risk. If you’ve done the basic checks and the system still misbehaves, call us at (762) 240-5599 and tell us what the system is doing – Victor will tell you exactly what it needs, no guesswork, no runaround.

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