Dishwasher repair

Nearly every dishwasher complaint arrives as one of four sentences: it does not clean, it does not drain, it leaks, or it does not dry. Each of those maps onto a different system inside the machine, and the value of the first visit is deciding which system you actually have — because a wash pump does not fix a drain, and a heating element does not fix a blocked spray arm.

The spray path

Spray arms block one jet at a time. That is what makes them deceptive: the machine keeps running, keeps sounding normal, and the wash pattern quietly develops a shadow. The upper arm goes first because it does the most work against gravity through the smallest jets, which is exactly why the classic symptom is a dirty top rack over a clean bottom one. Holding an arm up to the light and looking through every hole takes ninety seconds and settles the question.

Below the arms the list is short and testable: the sump filter and its screen, the chopper or grinder if the model has one, the wash pump impeller, and the diverter that decides which arm gets pressure at each stage of the cycle. A diverter fault produces a very specific complaint — one rack cleans, the other never does, and the machine sounds completely normal throughout.

Loading is worth ruling out before any of that. A tall board or a sheet pan laid across the lower rack shadows the entire upper arm, and a bowl inverted over the centre tower blocks the feed to it. Neither is a fault, and both produce a convincing imitation of one.

The drain path

Standing water at the end of a cycle is a drain fault, and the path has more parts outside the machine than inside it. We check the drain pump, the hose and its high loop, the air gap at the sink if one is fitted, and — on any machine installed or replaced recently — whether the disposer knockout plug was removed. That plug is a solid disc from the manufacturer, and a dishwasher plumbed into a new disposer without knocking it out will never drain a drop. It is the first thing we check on a machine that has never worked properly since it went in.

A drain that is slow rather than blocked usually means the sump filter is loaded, the hose has sagged out of its loop, or the pump is turning but tired. Those are different repairs and they are distinguishable in a few minutes.

Heat, dry and the element

A dishwasher cannot heat what it never received. We measure at the nearest tap, running until the temperature is steady, and we want to see about 120°F arriving at the machine. A long run from the water heater in a two-storey house can lose enough heat that the first fill is cold, the onboard heater spends the whole cycle catching up, and the results look like a detergent problem.

When the supply is right and the cycle still runs long, the element and its control are next. An element carrying a deposit is insulated from the water it is trying to heat, which lengthens cycles and eventually kills the element; a visual check plus a cleaning cycle is the routine, and a resistance check settles whether it has already failed open. Poor drying with correct wash results is a different chain again: rinse aid dispenser, vent or fan if the model has one, and the door opening at the end of the cycle where the design depends on it.

Leaks at the bottom of the door

Water on the floor at the door is usually one of three things: a door gasket that has taken a set and no longer springs back, a lower door seal that has hardened, or a machine that is out of level so the tub carries water to one corner. All three are inexpensive. None of them are worth living with, because the water travels under the cabinet toe kick where you cannot see what it is doing to the floor or the cabinet base.

Installation faults that imitate appliance faults

A dishwasher is plumbed both ways and fixed to the cabinet, and several persistent complaints come from the install rather than the machine. Out of level in either axis moves water to one corner of the tub. A drain hose without a high loop lets sink water siphon back. A unit fastened only at the front can rock when the racks come out, which works the door seal. A door that fouls a cabinet handle or an island stops short of its latch, and the machine reads that as an open door mid-cycle. All of these are corrections rather than parts, and all of them are cheaper caught early.

What we check before condemning anything

Filter and screen, both arms jet by jet, sump for grit, element by sight and by measurement, door seal by feel, level in both axes, supply temperature at the tap, and the drain path end to end. That sequence catches the majority of complaints without a part being ordered — and when a part is needed, you get a written estimate first.

What the visit includes

A flat diagnostic, credited toward the repair when you approve it, a written estimate before any part is ordered, and genuine OEM parts under our standard parts and labor terms.