The short answer
On the Costway EP dishwasher family a dishwasher that will not start is a door-latch problem far more often than a dead control board: the latch has to close a switch before anything on the panel means anything, and that switch is the first thing on the machine to wear. The brand-generic article ranks power supply first because it has to cover every chassis Costway sells; on this family the panel usually lights, which already tells you the circuit is fine.
What you see on the EP family
- The panel lights but nothing happens when you press start — The board has power and has taken the press.
- The door closes but does not feel like it latches — On this model you should feel the strike pull in and hear it seat.
- A start light blinks and then goes out — A blink-then-quit is the board starting a cycle and losing a permissive straight away — usually the latch switch opening again as the door relaxes.
- The machine is completely dark — No panel at all means the question is the outlet, the breaker and the junction box under the sink, in that order.
Causes, most likely first on the EP family
- Door latch and its interlock switch — Ranked first on the EP family — this is the part of a dishwasher that gets worked every single cycle and is the one most likely to be why this model will not start. The latch assembly carries a microswitch the control has to see closed. The plastic hook wears, the strike drifts as the door settles on its hinges, and the switch ends up marginal long before the door looks wrong.
- Control lock or delayed start left engaged — Second — worth a look before any tool comes out, because it is free to rule out and it mimics a board failure exactly. A held button sets the lock on most panels, and a bumped pad can set a delay.
- No power at the outlet, the breaker or the junction box — Third — it explains a dark panel completely and a lit panel not at all, so the panel state sorts it in seconds. A dishwasher is usually hard-wired or plugged into a switched outlet under the sink, and the connection lives in a damp cabinet.
- Thermal fuse or main control board — Fourth — and deliberately so: it is the least common cause and the only one that is not a homeowner check. A thermal fuse on the board opens after a heat event and kills the machine outright.
- Body: The order below is this family's rather than the brand's: with one build in the EP family the ranking is not an average diluted by chassis that fail differently, so the cause at the top is the cause that actually leads on EP24717US.
Check in this order, and why
- 1. Look at the panel before you touch anything — Lit or dark decides the entire rest of the sequence, and it costs nothing.
- 2. Prove the supply at the under-sink connection — Only once the panel is known dark. This is where a dishwasher loses power and it is the one electrical check that does not need the machine pulled out.
- 3. Clear the control lock and any delayed start — Hold the lock pad until the icon clears, then cancel and drain.
- Body: Because the EP family is one model, the access route below is the access route — there is no second layout to hedge against, which is exactly what the page above this one has to do.
Before you open anything
Safety
Kill the breaker before you open the junction box under the sink, and keep the water supply valve shut while you work in there. A standard US household branch circuit is 15 A or 20 A at 120 V, which is more than enough to be fatal in a wet cabinet.
Models in the EP family
Reference| Model number | Family key |
|---|---|
| EP24717US | costway:dishwasher:ep |
When to call a technician
Call once the panel is dark and the supply at the under-sink connection has been proved good, because the fault is then inside the machine and behind its lower access panel. Call straight away if you can smell scorched plastic at the door or see browning at the latch: on this model that means heat at the switch terminals, and that is a fire question rather than a start-button question.
Other EP dishwasher pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
