Ariston Washing Machine Door Lock – Bitron DL-S2 Interlock Switch

What this part does

The door interlock is the component that tells your washing machine the door is shut and holds it shut until the drum stops. Nothing else in the machine starts until this switch closes its contacts, no water fills, no motor turns, no programme advances.

Inside the DL-S2 is a PTC thermal element rather than a solenoid. When the machine powers the lock, the element heats, expands and drives the latch home. At the end of the cycle the power is removed and the element has to cool before the latch releases, which is why the door stays shut for a short period after the programme finishes. That delay is designed behaviour, not a fault.

Verified specifications

Every figure above is read from the markings moulded into the part in the product photographs. We do not publish specifications we cannot see on the component.

Part numbers this replaces

Is the interlock actually the fault?

Door symptoms are the most commonly misdiagnosed fault on a front loader, and replacing the lock when the control board is at fault costs you the part and the call-out. Work through these before ordering.

Points to the interlock

• Door shuts and latches mechanically, but the machine will not start the programme
• No audible click from the lock when the cycle is started
• Machine fills but will not spin, with the door firmly shut
• Door stays locked indefinitely after the cycle ends, long after the drum has stopped
• Continuity test across the switched terminals shows an open circuit after the lock has been energised

Points to something else

• Door closes but will not latch mechanically. the hinge, the striker plate or the door seal, not the interlock
• Machine dead, no display. supply, filter capacitor or main board
• Drains and reaches the end of cycle but door opens normally. The interlock is working
• Door releases if you restart and cancel.  usually the programme, not the lock

Before you test: disconnect the machine from the mains. The interlock terminals carry 250 V during operation. Do not test for continuity on a live machine.

How to confirm this is your part

1. Count the terminals. This unit has three, numbered 3, 4 and 5. A four or six-terminal lock is a different part and will not wire correctly.
2. Read the type number. Remove the old lock and look for DL-S2 moulded into the body, or DKS01 if yours is the ROLD equivalent. Both are supplied against the same machine part numbers.
3. Check the part number on your machine’s rating plate against the cross-reference table above. The plate is inside the door frame or behind the filter flap.
4. Compare the actuator tongue. The tongue must sit at the same height and angle as your original, or the door striker will not engage.
5. Send us a photo. If anything is unclear, photograph the old part on both faces and send it to us. We will confirm before you pay.

Why buy from Cool.sa

• We name the manufacturer and the type number. Most listings in this market say “standard automatic door lock” and nothing else.
• Cross-references published in full, so you can match against your machine’s own part number instead of guessing.
• Stock held in Riyadh and Khamis Mushait. not shipped in from Europe after you order.
• We check fitment before you pay if you send a photo of the old part.
• Trade pricing for workshops and service technicians.
  

Order this door lock

Cool.sa, Bitron DL-S2 interlock in stock now at both Cool.sa branches. Order online for delivery across Saudi Arabia, or collect the same day in Riyadh or Khamis Mushait. Not sure it is the right part? Send us a photo of the old lock and we will confirm the fitment first.

Frequently asked questions

Q1. Will this fit my Ariston washing machine?

It fits machines that take part number C00254755 or any of the cross-references listed above. Ariston, Hotpoint and Indesit share this interlock across a large number of models. The reliable check is the part number on your machine’s rating plate or the type number on the old lock, not the model name alone.

Q2. My door stays locked for a couple of minutes after the wash. Is the lock faulty?

No. A PTC thermal interlock releases as the heating element cools, so a short delay at the end of every cycle is normal. A lock that never releases, or that releases only when you cut the power at the wall, is a different matter.

Q3. What is the difference between the Bitron DL-S2 and the ROLD DKS01?

They are two manufacturers’ versions of the same interlock, supplied against the same machine part numbers. The bodies look different. Check the mounting hole centres and the actuator tongue against your original before choosing, or send us a photo and we will tell you which one you need.

Q4. Do I need to match the terminal numbers exactly?

Yes. Photograph the wiring before you disconnect it and reconnect each wire to the same numbered terminal. The terminals on this unit are marked 3, 4 and 5 on the connector block.

Q5. Can I run the machine with the lock bypassed?

No. Bridging the interlock lets the drum spin with the door unsecured. This is the one component on a washing machine that exists purely as a safety device.