How to Level a Dishwasher

A tub that leans forward holds water against the door seal. That water finds its way out onto the floor, and it can drip into the detergent dispenser before the cycle even starts, so the detergent is wet when the wash begins. A forward lean also lets the racks roll out on their own when the door opens.

A slight low-at-the-back attitude does the opposite: it lets the last of the water slide toward the sump, where the pump can pick it up. Too much rearward pitch is its own problem, because the front of the tub then sits high and the door seal no longer meets the tub evenly.

Side-to-side tilt shows up as rocking. Pull a loaded rack out and the machine shifts, the door can rub against the cabinet, and the pump and motor transmit more vibration into the floor. A unit that sits flat on all four legs runs quieter and latches cleanly.

If the racks slide out on their own, the door gaps are uneven or the machine rocks, the unit is out of level and needs adjusting.

• Rack roll-out check: open the door and pull the racks halfway out. If they slide out on their own, the unit is tilted forward.
• Door-gap check: close the door and look at the gaps on each side. The door should shut without rubbing the tub sides, with roughly equal space left and right.
• Rocking check: press down on opposite top corners in turn. Any movement means one leg is not carrying its share of the weight.

Standing water at the front of the tub after a cycle points the same way as the rack check, but confirm it with a level before you touch a leg, because a blocked filter or a slow drain leaves water in the same place.

A 9-inch or torpedo bubble level does the measuring, and a level app on a phone works as a backup. Add an adjustable wrench or a 1/4-inch nut driver for the legs, a Phillips #2 screwdriver for the toe kick, a flashlight to see the rear feet, a towel for the water that comes out with the kickplate, and a few shims.

Some rear adjustment mechanisms take a hex key or a small socket instead of a wrench, so check the installation instructions that came with your machine for the exact tool before you start.

Shims should be rigid: plywood, composite or hard rubber. Cardboard or soft plastic compresses over a few weeks and the machine drifts back out of level.

1. Cut the power at the breaker. If you will move the machine at all, close the water supply valve under the sink too. Ease it forward only a few inches, enough to reach the rear legs without stressing the water line, drain hose or electrical whip.
2. Remove the toe kick. Usually two Phillips screws hold it, sometimes with a piece of insulation behind it. Set both aside.
3. Check side-to-side. Lay the level across the top front edge of the tub, or on the open door, and note which side sits high.
4. Check front-to-back. The lower rack track inside the tub is the most reliable spot. A level held vertically against the closed door panel also works.
5. Adjust the front legs. Turn in quarter-turn increments and watch the bubble after each one. Push down or lift the top corner slightly to take the weight off the threads before turning.
6. Adjust the rear. Some machines have a screw or bolt at the front that drives the rear foot. Others have two rear legs you reach by easing the unit forward. Same method: a quarter turn, then look at the bubble.
7. Recheck both directions and repeat in small steps until side-to-side is centered and front-to-back shows the slight rearward pitch.
8. Tighten the locking nuts on the front legs if your machine has them, so the setting holds.
9. Reinstall the toe kick, restore power and run a short cycle. Check for rocking and for water at the door.

Side-to-side, the bubble should sit centered. Front-to-back, level or a slight rearward pitch of roughly 1/8 to 1/4 inch is right, and forward is never acceptable.

Leave at least a 1/2-inch gap between the top of the door or control panel and the underside of the countertop. That gap protects the controls from condensation and from screw heads under the counter.

All four legs, and the rear wheels on a portable, should sit firmly on the floor with no rocking. A quick recheck once a year, or whenever a new noise or a door problem appears, is enough to catch drift.

The legs carry the weight, but they do not stop the machine from tipping when a loaded rack is pulled out or the door is loaded with dishes. The mounting brackets that fasten the unit to the countertop or the cabinet sides do that job, and they are what keeps a level machine from rocking in use.

The machine also has to sit square in the cabinet opening. If the cutout is not square, the door will not seal evenly no matter how carefully you set the legs. The dishwasher should rest on its legs and rear wheels flat on the floor, not hang from the countertop.

A floor that is slightly out calls for a rigid shim under the low leg. A badly sloped floor is better handled with a plywood platform under the whole machine than with a stack of shims that can shift.

If a leg's threads strip, the leg can be repaired with jam nuts or replaced. Check the parts diagram for your machine to see which applies.

Soft flooring is a common cause of drift: a shim that compresses lets the machine settle out of level within weeks, so check it again after a month. If the door hits the cabinet, re-center the machine in the cutout rather than forcing a leg.

Lock the casters before you check anything. Then level the machine on the floor where it will actually run, not where it is parked between uses.

Both the leveling legs and the rear wheels must sit flat on the floor. The target does not change: level side-to-side, a slight rearward pitch, never forward.

Wheeling the machine back to the sink and hooking it up can shift the setting, so recheck the level once it is in place and connected.

These need a flat, sturdy counter. A sloped sink ledge or a surface that flexes under the weight will throw the level off and stress the cabinet.

Often a single shim under one corner is all it takes. Check with a torpedo level on the top edge and again on the open door, and never run the machine on a folding rack or any surface that gives under it.

Because these machines get moved on and off the counter, recheck the level each time you set one back down.

A slim built-in uses the same four-leg system as a full-size machine, but there is less clearance in the cabinet, so the 1/2-inch gap under the counter and the squareness of the opening matter more.

Check the level on the lower rack track inside the tub, as you would on a full-size unit. On some slim models the front levelers sit slightly below the underside of the countertop, so follow the installation instructions for your machine on the exact figure.

If the machine is level and water still pools at the door, the cause is more likely a blocked filter, a clogged sump or a drain problem. Check those before spending another afternoon on the legs.

A door that will not latch on a level machine usually means the unit is not square in the cutout, or that cabinet screws are bowing the tub. Back the screws off and re-center the machine.

Noise that survives leveling often comes from an unbalanced load or from the floor itself, especially on an upper floor with a flexible subfloor.