Sinking Air Conditioner Pad? Here’s How to Fix It

Your air conditioner must stay level in order to function properly and last as long as possible.

Replacement residential air conditioners can cost between $5,500-$16,000 for the unit, permit fees, and labor involved in the installation process. Regular air conditioner maintenance is one way to help avoid the need to shell out big sums for an early A/C replacement, but there’s often more to it than that.

At A-1 Concrete Leveling, every year we see thousands of customers struggling with a lesser-known problem: sinking concrete A/C pads and the damage they can cause to the unit.

Luckily, there’s a simple way to lift sunken A/C pads back up into the right position, helping to prolong the life of your unit and keep you cool in the heat. This article will take a look at how and why to do just that.

How to Fix a Sinking Air Conditioner Pad

Lifting your sunken A/C pad can be done with professional concrete leveling, a DIY method, or replacing the slab altogether.

Professional Concrete Lifting

Lifting the sunken A/C pad with professional concrete lifting/leveling services is a safe, quick, and permanent solution.

Related Resource: How Much Does Concrete Leveling Cost?

Process

To lift a settled A/C pad, concrete leveling technicians follow these three steps:

1. Drill strategic holes throughout the pad.
2. Slowly pump a dense compound through the holes which fills voids below the slab. Pressure builds up, allowing the technicians to carefully raise the slab back up to the correct position. 
3. Patch drill holes and clean off the area.

How the A/C pad is lifted depends on the size of the condenser unit, the size of the concrete pad, and where the lines running from the A/C to the house are located, but the strategic holes are drilled and the slab is carefully lifted with these things in mind. 

Unhooking or Removing the A/C Unit

If everything on your A/C unit is original, you most likely will not need to unhook the air conditioner before having the concrete slab lifted back into place.

However, if there have been repairs on the lines running from the house to the A/C condenser unit after the pad settled, it will likely need to be unhooked before the pad is lifted.

This is because when the lines are repaired after settling, they are installed to fit the settled position, and once lifted, they may no longer reach and break.

Concrete Leveling for a Sunken A/C Pad

 

BEFORE —

The concrete slab settled to one side, making the A/C unit unlevel.

AFTER —

The slab was lifted back up and stabilized with A-1's ControlLevel™ system.

DIY Sinking Air Conditioner Pad Fix

When searching how to fix a sinking air conditioner pad, you will likely come across recommendations to jack up the concrete slab yourself and pack material underneath.

DIY Process

To lift and level the concrete A/C pad, many sources around the web will tell you to do some variation of the following:

1. Wedge a jack or a long wooden board under the settled part of the concrete pad
2. Using the jack or board, lift the concrete slab up
3. Pack sand or gravel under the slab, then remove the jack or board

DIY Process vs. Concrete Leveling

While a DIY fix may work, professional concrete leveling comes with some of the following benefits that make it worthwhile for lifting up settled concrete A/C pads: 

• Leveling technicians work back and forth on the slab and bring it up slowly, which puts less strain on the unit itself
• Most concrete leveling companies provide a multi-year warranty
• Material pumped under the slab with concrete leveling is pressurized and stabilizes the slab, whereas hand packing does not properly stabilize the slab

Related Resource: Can You DIY Concrete Leveling?

Replace the Slab

Another option for fixing a sinking A/C pad is to replace it altogether. This option is the most expensive and most time-consuming, but it will solve the problem.

A/C Pad Replacement Process

1. Unhook and remove the air conditioner unit
2. Tear out the settled slab
3. Pour a new concrete slab and wait for it to cure
4. Move the unit back and reconnect

Why Should You Repair a Sinking Air Conditioner Pad?

To keep your A/C condenser (the entire unit that sits on the concrete slab outside your home) in good working order, it has to stay level. When an air conditioner pad sinks and makes the condenser unit unlevel, it can cause:

• System Strain

When an air conditioning unit is off balance, its vibrations are made stronger and cause the components inside (motors, fans, etc.) to break down faster and refrigerant lines to loosen.

• Broken Pipes and Tubing

The pipes and tubing that run from the condenser unit to your home are crucial to a functioning A/C system, but if the unit sinks down with the concrete slab, it can put pressure on them and cause them to break off or snap.

• Off-Level Compressor

The compressor is a crucial component of an A/C condenser unit, but if it’s off balance, the oil within the compressor will become unlevel, which can cause overheating, a decrease in efficiency, and premature wear.

• Water Pooling

Unlevel A/C condenser units can cause the water within the system to pool rather than drain like they’re supposed to. This can lead to higher humidity within the unit, which may cause mold or rust.

Your Next Steps: Lift Your Sinking A/C Pad

Letting your air conditioner condenser unit stay out of level can cause lots of problems, so being proactive by lifting the sinking concrete pad is one way to help make sure your home stays cool on the hottest summer days.

Here at A-1 Concrete Leveling, we’ve been lifting settled A/C pads and other types of sinking concrete for over 30 years. If you’d like to see what concrete leveling can do for your A/C pad, request a free estimate!