Jump to content
Appliance Offers
TimD

Water pressure woes; curious about washing machine's pattern of intake use

Recommended Posts

We have a washing machine plumbed into (cold water only) a non-mains supply from a low header tank in our flat.

An old 1bar minimum machine (Bosch) used to repeatedly time-out on fills.  Could be prodded to carry on from where it had left off, but pretty annoying.

We eventually (when that broke) replaced that with an AEG which supposedly worked down to 0.5bar and that did seem to be much better behaved.  But recently it too started misbehaving.  Timeouts on fills, but also the conditioner drawer compartment didn't seem to be getting any water.... instead of dripping through the roof above the conditioner, the water just seemed to be dripping down at the back of the drawer.

Checked and cleaned all the intake pipes and strainers.  No obvious issues and no improvement .

Checked the water pressure by a "bucket fill" test: 3-4litres/minute.  Which is interesting, because back in February 2009 I posted on your article here https://www.whitegoodshelp.co.uk/low-water-pressure-and-washing-machines/comment-page-4/#comments that we were getting 5.  Some information with the old Bosch machine claimed the 1bar minimum should produce 8... so something seems to have happened to reduce our water pressure below the machine's 0.5 bar minimum (and so not too surprising we were now having issues).

Unfortunately the header tank is pretty inaccessible (in fact I only just discovered where it is; what I thought was it actually turned out to be for the central heating's pressurization), and it has so far strongly resisted attempts to get a closer look at it.  Maybe this is all down to something as simple as a dead mouse blocking the tank outflow... but if it is I've no idea how we're going to do anything about it.

So instead I went down the route of what your low-pressure article said not to bother trying and got hold of a flow-activated pump.  Sticking a takeaway container in the detergent-and-conditioner drawer got me an estimate that the machine would take 0.75litres/minute when the intakes were activated, so I looked for the lowest flow-activation I could find and got one which triggers on 0.5l/minute (most are up nearer 1l/minute it seems).  Pump claims to be 2bar pressure BTW.

Initially it looked like it was going to work pretty well: with the pump assisting, the flow into the machine became a magnificent cascade (compared with how it had looked before anyway) and it filled in record time.

However, there seems to be a fatal flaw.

On the machine's quickest 30 minute wash, the pattern of intake (there are a couple of electronic-activated valves at the machine intake, each controlling a pipe to the detergent or conditioner compartment sides of the drawer) seems to be:

1. Via the detergent drawer.  Full pumped flow.  Great!
2. Via the conditioner drawer.  However valve seems to only partially activate and flow is insufficient to trigger the pump.  With the pump in the circuit, flow is even more of a trickle than it was before and we get a timeout and the conditioner drawer doesn't get any water.
3. Via the conditioner drawer again but this time the intake valve seems to fully open, the pump kicks in and the conditioner drawer gets flushed/syphoned out.  Great!
4. Via the detergent drawer again for a final rinse.  Full pumped flow.  Great!

Further, we note that on the "wool wash" cycle the initial fill also seems to do the thing with the initial fill that it only partially opens the detergent-compartment intake and water just trickles in (resulting in timeouts of course).

So, not a success or a solution.

The thing which really surprised me was that the intake valves seem to be able to select between (at least) a couple of flow rates... I'd have assumed they'd have no need to be anything other than either on or off, and if they did just do that, the pump would probably be a pretty good solution.  In fact I did initially think there might be some issues with the valves "sticking" but the flow pattern seems to be so consistent between cycles it must be under the machines control.  I'm quite curious as to what the reason for it is though.

However, looks like a real solution will involve figuring out the reason for the pressure drop and/or getting at that inaccessible header tank.  Or getting the machine plumbed into the main (which must pass quite near it on its way under the flat to the kitchen).  Either way, looks like time to get a pro in.

Edited by TimD
initial post was incomplete; sloppy clicking
  • Like 1

Share this post


Link to post
Share on other sites

Book washing machine & appliance repairs

Ransom Spares

Note: The links above are needed to help keep this site running, please consider using them.

Hi Tim. How many water valves are in the washing machine? It sounds like one valve (or solenoid) is working great but another not so good. They don't regulate flow that I know of, they usually just have 1 - 3 solenoids, one for pre-wash and rinses, one for main wash and one for the fabric softener.


Need an engineer, or to buy appliance spare parts? Please use my affiliate links to support this forum.

Book appliance engineer | Buy your appliance Spares 

Warning:  Read this before attempting any diy repairsNo representations or warranties are made (express or implied) as to the reliability, accuracy or completeness of advice. I can't be held liable for any loss arising directly or indirectly from the use of, or any action taken in reliance on, any information on this website, which is given free of charge and in good faith.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


Book washing machine & appliance repairs

Ransom Spares

Note: The links above are needed to help keep this site running, please consider using them.



×
×
  • Create New...