Washing machine pressure switch, how to fit, replace and Diagnose the fault related to it

by / Monday, 19 August 2013 / Published in Repair Guides, Washing machines, Water Systems & Valves

Washing machine pressure switch, how to fit, replace and Diagnose the fault.

This video will show you the associated faults with a washing machine pressure switch and air chamber.
To order your washing machine pressure switch you will need your full model number (This is normally around the washing machine door frame on a sticker)

testing-a-washing-machine-pressure-switch

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Washing-machine-pressure-chamber

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Washing-machine-pressure-chamber-with-hose

Inside-a-Washing-machine-pressure-switch

 

Associated Faults with a washing machine pressure switch and air chamber:

    1. Overfilling.
    2. Intermittent Over or Under Filling.
    3. waiting a long time for the door to open after a wash.
    4. will not go into spin; it turns as though it wants to but then stops.

The Washing machine will not go into spin; it turns as though it wants to but then stops.

The most common cause for this is the pressure chamber being blocked, or the pressure switch not resetting, either way the machine thinks it still has water in it and will not go into spin. An easy way to check is to remove the hose connected to the pressure switch blow into it and listen for clicks depending on what level settings it has will depend on how many clicks there are, this will happen the instant the hose is removed so be aware, if you hear a click it means the switch has reset so the chamber is possibly blocked but if there is no sound then either you missed it or the switch is at fault. To test the switch you may have to remove it because you will need to blow into it and listen for one or more clicks as the different levels set. Be aware that some of the older machines have multi level switches, whilst the newer ones only have a single level.

The pressure switch controls the fill valves, and in some cases will prevent the motor from going into spin. It operates via an internal diaphragm which triggers one or more switches (depending on the type of pressure switch). Water entering the drum as the machine fills gradually fill the pressure chamber and traps the air already in it. As the water level in the drum rises so the pressure on the air increases, this air is then forced up a small bore tube which connects both chamber and switch. When the correct pressure on the internal diaphragm is attained the corresponding switch is activated.

You have to wait a long time for the door to open after a wash.

It could be the pressure chamber is blocked, if so you will probably notice more water in the machine and the cloths coming out wetter than usual. Removing the pipe from the pressure switch and blowing down it may resolve the problem for a few washes but the chamber will need to be removed and cleaned properly for a lasting solution or you might have a separate pipe going to the door lock which might be blocked but you will also need to see other tutorials on washing machine door interlocks.

Washing machine is over filling and may be flooding your kitchen

The problem here is the pressure switch is not operating, this can have a number of causes, either the switch is faulty, there is a hole in the pressure pipe or it has come off, or the most common reason is the pressure chamber is blocked. To check the switch you have to blow into it and listen for one or more clicks, if you hear them it’s fine, a close inspection of the hose should tell if it is OK or not, whereas the chamber has to be removed and washed out to clear it. If it was screwed on then it will go back in the same position but if it was held on by a clip or glued in place then make a note of the hoses location because if it was put back wrongly positioned you could have more water in the drum than needed resulting in a flood.




24 Responses to “Washing machine pressure switch, how to fit, replace and Diagnose the fault related to it”

  1. RM says : Reply

    A related problem with similar symptoms is simply that the hose(s) to the pressure switch are clogged up. Check the switch itself as above, but clean out the hoses (i.e. the pressure tube) too. Or at least check them by blowing through.

  2. monem khadr says : Reply

    u gave me me a great help …thank u

  3. Peter says : Reply

    Brilliant !!!!!!!

  4. Phred says : Reply

    Very very helpful thank you so much turned out my pressure hose was blocked, easy fix saved me a lot of money 🙂

  5. marcos lopez says : Reply

    my pressure switch works, tube is ok and i see water flowing out from the unit(washer) into hose . is this normal?i can’t figure out why water is over flowing?the pressure is not getting up the tube to shut off the pressure switch . tube is new , pressure switch is new. it is an issue where the tube is not getting enough pressure to shut off pressure switch.

  6. Tracey says : Reply

    My washing machine won’t wash. It fills up with water but won’t wash. The belt is fine the water has been emptied below. Want to be able to fix this myself.

  7. Tysun gandy says : Reply

    Washer pump does not shut off even when there’s no water in it. I’ve read that it might be the pressure switch or hose to it. I’ve blown through the hose and it’s clear, so I check the pressure switch with a meter and as I blew in to it nothing change so I’m guessing it’s a bad pressure switch?

  8. Diddi says : Reply

    Hi Paul – I have an elderly (90) neighbour with advanced dementia – who has an AEG lavamat 86741 washing machine – with an error code C6 on it. The machine was only replaced yesterday by a (very good) builder having been moved out for a week, while flooring was replaced, due to a burst pipe! So lots of washing to catch up on. Is this something I can help her with – or do we need yet another tradesman to come out – which is do disruptive for her? Thank you.

  9. Liz Kendray says : Reply

    Hotpoint WMFUG942 13 months old – will not fill with water. Error code F05
    It will take a very small amount of water in part of the rinse cycle.
    Have checked the filter, removed the drainage pump and hose from drum to pump – pretty gunged up but now clean. Have checked the outlet pipe. Put 2 gallons water into drum and selected pump – all the water cleared easily.
    Have replaced the cold water fill solenoid with genuine Hotpoint part. Still the same problem.
    Have remove tube at base of pressure sensor – NO audible click heard. Have blown through tube and it was clear. I have gently blown and sucked the base of the pressure sensor and can feel movement, but no audible click.
    Tried to locate the pressure chamber – could not find one.

    Any ideas? Do I need to replace the pressure sensor?

  10. Stephen Porter says : Reply

    Hi, I have a Bosch wfli2440 washing machine. It has started intermittently leaking from the drawer. It only happens on the rinse cycle (more often on a heavier load). I have cleaned out drawer, both inlet pipes from water inlet are clear, as is the outflow to the drum. Basically, seems to pump more water to drawer than it can handle on rinse cycle, but not every wash. Thanks for any help

  11. Bea says : Reply

    Hi,

    My washer machine, make: LSE7804ACE; serial number: `5954457MQ, overflew. I read and understood that I needed a new water pressure switch: PN 12002304. I got a part that does not look like the old one. I followed the instructions, which refer to location 13,23 and 33; there are no such locations. Anyways, I use 14, 24, 34. However, the machine washes but it does not spine/drain. Would you please tell me where the wires go?

    Please I need your help.

  12. Mandy says : Reply

    Hi, I have a Candy Grand’O 2 years old- it is filling fine, in fact seems to fill up a bit more than usual but that may just because I am watching it! It then just stops and Error code 2 comes on (2 blinking lights then a pause). When it is filling the drum does not rotate that it usually would either. I can turn off and then set to spin and it will empty and spin fine.

    A diagnose would be greatly appreicated!! I have checked the restistance reading on the solenoid valves and they are fine.
    Thanks!

  13. Pirthipal says : Reply

    Have Samsung washer Wf331ANW/xaa .getting nf code.after filling some water. But when run on rinse and spin it works .

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