Thermador dishwasher left standing water in the sump

Where the visit starts

A dishwasher gives up its fault in a fixed order, and working that order is what keeps a cheap repair from being quoted as an expensive one.

We start at the filters and the sump, because a coarse filter packed with debris changes wash pressure, drain behaviour and cycle length at once and costs nothing to check. Then fill: the machine should take a known quantity in a known time, and a slow fill points at the inlet valve, its screen, or a supply stop that was never fully opened after an install. Then heat, measured across the cycle rather than assumed, because almost every “it takes two and a half hours now” complaint is a machine extending itself trying to reach a setpoint it cannot hold.

Only after those three do we look at the circulation pump, the drain pump and the control. Boards are the most expensive part in the machine and the least often actually at fault.

Cloudy glassware

The most common call is not a fault at all. Cloudy glassware is usually a combination of deposits left behind by the wash and detergent that never fully dissolved, and the first two things we check are whether the machine is reaching temperature and whether the rinse aid dispenser is actually dosing.

A weak heating circuit turns a chemistry problem into a permanent one, because detergent enzymes and surfactants need heat to work. If the incoming water is cool and the heater is marginal, the cycle extends itself trying to reach setpoint — which is why “the cycle takes forever” and “the glasses are cloudy” usually arrive as the same phone call.

Etching is different from film. Film wipes off with a vinegar soak; etching does not, because the glass surface itself has been attacked. We will tell you which one you have before you spend money on the machine, because one of them is a maintenance conversation and the other is not repairable at all.

Spray arms and the fine holes

Spray arm jets are small by design — that is what makes the water hit hard. Food debris, detergent residue and deposits narrow them from the inside, and the arm’s rotation slows because the reaction force it depends on has dropped.

The pattern is diagnostic. If the top rack cleans and the bottom does not, the lower arm or its feed is restricted. If one wedge of the rack is consistently dirty, an individual jet is blocked. If nothing cleans well and the arms turn sluggishly, the circulation pump or the filter is the place to look, not the arms.

We pull the arms, check every port, and check the fine and coarse filters — which in a beach house that rinses sandy plates fill faster than the manual assumes.

Standing water and drain faults

Water in the sump at the end of a cycle has a short list of causes: a blocked filter, a clogged drain hose, a drain pump with something jammed in the impeller, a check valve holding open, or a high loop that was never installed and is letting the disposal siphon back.

The high loop matters more here than people expect. In older cottage kitchens the drain line frequently runs straight across to the disposal with no rise, so every sink use pushes water back toward the dishwasher. That is thirty minutes of plumbing and it gets quoted as a drain pump more often than anything else on this list.

Drying, doors and panels

Wet dishes at the end of a cycle are normally either a rinse-aid dosing problem or a vent that is not opening. Condensation drying depends on the load coming out of the final rinse hot enough to flash the water off, so a marginal heater shows up here too.

Door faults are mechanical and mostly about weight. A panel-ready dishwasher carries a custom cabinet front, and the door spring must be tensioned for that weight. When it is not — usually after a kitchen refresh with a heavier panel — the door drops, the hinge wears, the latch stops aligning, and the machine refuses to start because it cannot confirm the door is closed.

Retensioning a spring and realigning a latch is inexpensive. Replacing a hinge assembly that has been abused for a year is not.

Getting the machine out from under the counter

Most of what goes wrong is serviceable in place. Pump, filter, heater and control work happens from the front with the door open and the toe-kick off.

Some of it is not. A leak from the sump seal, a failed inlet valve behind the tub, or damage to the drain connection means the machine comes forward, and that is where a built-in installation shows its history. The custom panel comes off first. The water line, the drain and the power connection are all live under the sink cabinet and have to be isolated before anything moves. Levelling legs are often seized, and on a stone counter the machine may be clamped or bracketed to the underside rather than screwed to the cabinet sides — forcing it forward against a bracket is how counters get chipped.

We check that before we pull, and the access time is written into the estimate rather than added to the bill afterwards.

How the visit works

Flat $80 diagnostic, credited toward the repair. Written estimate before anything is ordered. Genuine OEM parts, 90 days labor, 365 days parts. We service Thermador only, and we will say so on the phone if your machine is another make rather than take the fee for a visit we cannot finish.