Most Cove dishwasher repair calls come to us after another appliance shop has already taken a look and didn’t get far. A Cove isn’t a normal dishwasher. They’re newer than the rest of the Sub-Zero Group line, so not many independent shops have seen a lot of them.
Here’s what goes wrong, in the order we find it.
Not draining
It’s almost always a clogged or badly seated drain hose, or a filter nobody has pulled out since the machine was installed. Take the bottom filter out and rinse it under the faucet. While it’s out, look down into the sump (the well at the bottom of the tub) for a piece of glass or a fruit sticker sitting over the impeller, the little spinning part that pushes the water out.
If the hose is shoved too far into the standpipe, or it has no high loop, the machine will also pull dirty water back in. That’s a problem with how it was installed, not a broken part. Get it fixed right instead of living with it.
Not cleaning well
Check two things, in this order: the filter, then the spray arms.
Arizona Arizona water runs 16 to 28 grains per gallon, which is very hard water. The national range is 7 to 10. So scale builds up in the spray arm holes long before you can see it.
Hold the arm up to the light. If the outer holes look smaller, clear them with a toothpick and run a cleaner through an empty hot cycle.
The third thing, and the one people don’t expect, is the water valve where the water comes in. If it’s only opening part of the way, you get a full cycle without enough water in it. That looks exactly like a spray-arm problem.
Not starting
Make sure the door latch catches straight. A Cove won’t run if the door lock isn’t satisfied, and if you have to push the door to close it, the latch is fighting it. Past that, it’s usually the control board or the thermal fuse (a safety cutoff that trips when things get too hot). That’s where a home fix stops.
What we’d do before calling anyone
Pull the filter, rinse it, check the spray arm holes, and run one hot cycle with a dishwasher cleaner in it. That takes care of a good share of the calls we get. We’d rather tell you that up front than charge you to come out and say it.
Note If it’s still acting up after that, the problem is electrical or in the pump. Neither one is a homeowner job on this machine.
Water temperature and detergent
People rarely suspect these two, and both are cheap to rule out.
A dishwasher wants the water coming in at about 120 degrees. If your kitchen faucet runs cold for twenty seconds before it warms up, the machine starts its cycle on cold water and the detergent never dissolves all the way.
Tip Run the faucet hot before you start a load. It costs nothing, and it fixes a real share of “not cleaning” complaints.
Detergent is the other one. On hard water, powder and gel both have a tough time, and an old box of powder that’s soaked up moisture is close to useless. Tabs with rinse aid built in do a lot better here. And if the rinse-aid reservoir has been empty for a year, fill it before anyone blames the machine.
The door seal
Look along the bottom of the gasket for a flat spot or a split. A Cove door is heavy, and the seal takes that weight every time it closes. A leak there shows up as a wet spot on the floor an hour after the cycle ends. That sends people looking at the pump and the hose, when the problem is right in front of them.
When we’d tell you not to fix it
If the control board has died on a machine that’s out of warranty and more than eight years old, the board plus labor usually comes close enough to the cost of a new one that we’ll tell you so. Nobody here works on commission, so we’ve got no reason to talk you into anything. On a Cove, the math leans more toward repair than it would on a budget machine, because the rest of the unit is built to keep going. But it’s still math, not a rule, and we’ll run the numbers with you on the phone.
What to have ready when you call
Have the model number handy. It’s on the edge of the tub behind the door. Then tell us what the machine is doing, not what you think broke. “It fills, runs, and the dishes come out gritty” tells us more than “the pump went out,” and it’s right more often.