washing machine door locks

[andyr12345]

I wonder what the rating is for these newer door locks that are on washing machines these days (am talking about the door locks that unlock immediately after the cycle has finished - not the older washing machines that you had to wait a minute or so before you could open the door after the cycle has finished) 

Only sometimes our new (well year and half ) Samsung eco-bubble  and Hotpoint one did too, dims the lights sometimes when it unlocks or locks so they must be particularly a bit heavy on the amperage to do that - noticed as well on a couple of occasions if had tumble drier and EV charging (on 13a granny cable) that the washing machine door lock as opened and tripped the consumer unit like theres an overload or brief leakage to earth as it unlocks. Its doubtful that the lock is broke and its unlikely that there is anything wrong with the consumer unit / over-sensitive RCD/MCB's - it just seems these locks can be quite heavy for a split millisecond when they unlock sometimes.  

[Whitegoodshelp (Andy)]

Hi Andy. Do they really unlock the door immediately after the cycle is finished, or is that just a trick? When a washing machine has finished, the door lock needs up to 2 minutes to cool down before the door can be opened. This was often frustrating for users. But someone came up with the clever idea of changing it so that when the spin cycle had finished, they cut the power to the door lock - but didn't actually indicate that the washing machine had finished until two minutes later. By which time the door would open. This made a lot of sense, but essentially was just a trick

In order to allow the door to open immediately after the wash cycle has finished, it needs to be able to detect water levels, and movement of the drum. I remember the Hotpoint door lock was great, as it only operated when the drum was turning, and the second that the washing machine finished the door would open. Unfortunately though, it was just a terrible design and suffered from multiple problems.

I remember Hoover created their own version. But ultimately any system that allows a door to be opened immediately - as long as there is no water in the drum, and the drum is not revolving, is technically more advanced and complicated, and therefore more expensive. So most washing machine manufacturers just rely on the cheap bi-metal door lock's that have to physically cool down.

I don't know if they have invented anything different?

[andyr12345]

hello Andy thank you for the answer. - yep it looks (sounds?) to be a solenoid type door lock and not a bi-metal one on this Samsung later eco-bubble and on my older Hotpoint , purchased in 2012 (which my daughter now owns) 

after spinning on mine (samsung) it does 3 slow revolves to relax the clothes after spinning in the drum and then a loud click (like a solenoid) and you can open up the door immediately - no waiting around for door to unlock. 

On hers now (the hotpoint) after spinning he clothes stay stuck to edge of drum - the time says 1minute left, the pump empties out , it does end of wash quick jingle and the lock makes 3 clicking noise (with a solenoid) and door can be opened up immediately. 

on a backup, older Samsung I have, it finishes its spin, does its end of cycle jingle, then no clicks of a solenoid and have to wait 1or 2 minutes whilst the bi-metal door lock cools down and then can open door . 

i dont know if any connection, but our newer Samsung eco-bubble has an inverter wash motor and our older back up samsung eco-bubble has the old type carbon brush type wash motor. 

 

[Whitegoodshelp (Andy)]

2 minutes ago, andyr12345 said:

yep it looks (sounds?) to be a solenoid type door lock and not a bi-metal one on this Samsung later eco-bubble

Ah, if I remember correctly servis used to have a door lock that was solenoid operated. And I'm pretty sure my Miele washing machine has a solenoid one too. They are obviously more expensive, and arguably more prone to failure, so the majority of washing machines stick to the cheap bimetal ones.

[Whitegoodshelp (Andy)]

21 hours ago, andyr12345 said:

dims the lights sometimes when it unlocks or locks so they must be particularly a bit heavy on the amperage to do that

Now I know that it's solenoid based I can see what you mean. Yes I would imagine it would need to be strong enough to be able to physically operate a mechanism so I would expect it to be mains voltage but it's hard to imagine how it would take too much current as it is only a magnet with a coil wrapped around it.

[andyr12345]

2 hours ago, Whitegoodshelp (Andy) said:

Ah, if I remember correctly servis used to have a door lock that was solenoid operated. And I'm pretty sure my Miele washing machine has a solenoid one too. They are obviously more expensive, and arguably more prone to failure, so the majority of washing machines stick to the cheap bimetal ones.

on a bimetal one I wonder how many people have broken the handle/door catch furiously tugging trying to open the door when its still locked at the end of the wash 😁

I remember when we first got our hotpoint with it previous machines had bimetal and it used to wind my mrs up when it had finished a cycle and she was waiting to opening the door and saying how ridiculous it was that the cycle had finished and the drum was not moving so what on earth wash all the delay for! - and being very impressed on the new hotpoint unlocking immediately at the end of the wash . 

[MelS]

Those thermal catches are really infuriating, especially when you realise you left something out a few seconds after hitting the start button and have to wait two, to three minutes to put it in and continue the wash.  

I miss the instant lock on the Hotpoint my parents had during the 80s and 90s, never had any problem with the locking mechanism, it was a fully mechanical cable operated lock, with the door release button on the control panel and a "pecker" that pressed against the belt on the drum pulley, so the sprung plastic "beak" would pivot if the belt was moving allowing the cable sheath to move so that the cable wouldn't pull open the door catch, and I think it also had a mechanical pressure linkage for water level. It would only open when the drum was stationary and the water was below the door as I recall, even if the power was off. Ironically the machine was microprocessor controlled.  

 

There's an illustration of an instantaneous door lock as used in Electrolux brands as well as for the various other washing machine components in https://tds.electrolux.com/others/599/376/782EN.PDF Uses a solenoid and a ratchet mechanism and requires two triacs to operate it. 

[MelS]

On 14/11/2023 at 15:23, andyr12345 said:

I remember when we first got our hotpoint with it previous machines had bimetal and it used to wind my mrs up when it had finished a cycle and she was waiting to opening the door and saying how ridiculous it was that the cycle had finished and the drum was not moving so what on earth wash all the delay for! - and being very impressed on the new hotpoint unlocking immediately at the end of the wash . 

 

The hotpoint we had after the Microtronic used a bimetal latch, we used to keep a screwdriver handy to pop in the release slot in the side of the door, rather than wait! 

 

[andyr12345]

bimetal=nice & quiet unlocking - caveat: , having to wait for it to unlock
Solenoid = handy that it opens the latch immediately when washing done - caveat: noisy loud clicking 

on the Hotpoint we had in another room sometimes we heard the washing cycle had finished not by the end jingle it played but by the clicking  of the door lock instead! 

[MelS]

A video showing the workings of a Samsung instantaneous door lock popped on youtube: - 

 

youtu.be/3dLhBoBC1DM?t=517

 

This thread has got me wondering if I could modify my machine's control board to use an instantaneous lock, it is possible that the firmware might support both (I'd have to check the outputs on the board).  

[andyr12345]

looks quite elaborate that one! - looks like it would be expensive part too - I see thats an American Samsung , I wonder if the UK/Europe ones have the same type door switch as that 

[MelS]

Good point, I just checked a random UK parts site, and found one samsung lock that looks quite similar and must use the same mechanism, and yep was expensive (~£80), but also a fair selection of different designed ones too, so quite likely not what most UK ones have. 

It doesn't look as complicated as the Electrolux one, that's got a solenoid to operate it, plus a thermal catch that will apparently release the solenoid lock if the power fails after a delay, instead of the manual release on that samsung one.

 

Edited November 17 by MelS