Opening the dishwasher to a puddle of dirty water is annoying, but it's usually one of a few simple things, and several of them you can check in ten minutes.
First: is it really not draining?
A little water is normal. GE's guide says that on models without an ultra-fine filter, 1 to 2 cups of clean water covering the bottom of the tub is normal. On models with an ultra-fine filter, some water in the sump (the well under the filter) is normal, but it shouldn't cover the bottom of the tub. Dirty water, or water above the filter, means something is blocking it.
Check these yourself (power off first)
- The filter. Twist out the filter at the bottom of the tub and rinse it. A clogged filter is the most common cause. While it's out, look in the sump for broken glass, bones, labels or seeds.
- The kitchen sink drain. The dishwasher usually drains into the sink drain or the garbage disposal. If the sink drains slowly too, the clog is in the sink drain, not the dishwasher. Run the disposal before starting the dishwasher. Never put your hand in the disposal.
- A new garbage disposal? If the disposal was just installed or replaced, the small plug inside its dishwasher inlet may still be in place. InSinkErator's manual says that plug must be removed or the dishwasher may overflow. The disposal has to come off or be reached from below to knock it out, so this is usually a call to whoever installed it.
- The air gap. That's the little chrome cap on the sink deck next to the faucet, if you have one. Pull the cap off and clear out any gunk. Water spitting out of the air gap during a cycle is a sign the line below it is clogged.
- The drain hose. Look under the sink for a hose that's kinked or crushed behind the cabinet or by stored items.
- Detergent. Too much soap, or hand dish soap, makes suds that keep the dishwasher from draining properly.
Don't pour drain cleaner into the dishwasher. GE says not to, and it can damage the parts and the pipes.
When it's a plumbing problem
- The sink and dishwasher both back up, or water comes up in the other sink: the clog is in the shared kitchen drain line. A plunger or chemicals rarely clear grease buildup in that line; it needs a cable or drain cleaning.
- No air gap and no high loop: without an air gap, the drain hose has to loop up high and be fastened under the counter so dirty sink water can't run back into the dishwasher. GE's install instructions give the height for each model. A hose lying on the cabinet floor can cause bad smells and poor draining.
- It drains, but the sink gurgles or smells: often a venting or trap problem in the kitchen drain.
When it's the dishwasher itself
If the filter is clean, the sink drains fine and the hose is clear, the problem is likely inside the machine: the drain pump or its controls. That's an appliance repair; check your warranty and the maker's service line first.
Washing machine not draining? Same idea. If the standpipe behind the washer overflows or the laundry sink backs up, it's a drain. If the drum stays full and the drain is clear, it's the washer's pump.
When to call
Call when the kitchen sink is slow or backing up too, when the disposal was just installed, when water is under the sink or coming up somewhere else, or when it keeps happening after you've cleaned the filter.
OX Plumbing clears kitchen drains and installs disposals across the East Valley and answers 24/7. Our $99 service call covers the visit, the diagnosis and an upfront price before any work starts.