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BANGKOK 19 May 2019 15:42
Andrew Dwyer

Water pump pulsing

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Not sure if I have a problem or not really, but here goes.

 

Have lived in this house for nearly 2 years now, the pump, tank and pipe work was fitted just before we moved in .

I have noticed that the next door neighbours pump pulses ( 2 sec on 2 sec off ) when I assume he is showering.

Ours never did that, or I never noticed it anyway, pump always on.

 

This week had tiling done outside and lifted the pump and tank by 10” onto a steel frame, pipe work modified for height but exactly same as before.

 

Now when showering I can hear the pump pulsing ( 3 sec on 3 sec off ) something I never noticed before, if another tap is opened or toilet flushes the pump stays on constantly.

I mentioned it to the gf , she said that now that the pump is on the steel frame it is louder ( which it is ) and nothing has changed. ( will also look at some rubber material to reduce the pump noise, steel frame has rubber feet).

 

It does seem logical that the pump delivers more water required for just the shower hence it turns on and off and stays constant when an additional tap open/toilet flushes calls for more water.

 

Or am I missing something obvious here, as the pump and tank were drained to lift them do I need to prime the pump or something of this nature. ??

 

Am convinced that it has changed since lifting up !!

 

Couple of photos of the pump.

 

IMG_1503.JPG

 

IMG_1502.JPG

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I could be completely wrong, but is that the correct pump to use for your application? It seems to have a very small pressure tank, but there again the specs say it is a constant pressure pump.
At the back/side near the filler cap looks like your pressure switch. You can adjust the switch (with an insulated handled screwdriver) so the pump stays on during shower.
Maybe best first thing to empty all the water out and recharge it again.See if that makes a difference.
I put a pressure meter on my pumps to see what's going on.

Sent from my SM-J700F using Tapatalk

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I have the same pump, with the same issues. Our pump issues started after our tank ran dry one day. Kind of annoying but not a big issue. It probably has something to do with the pressure regulator or more likely the bladder tank. The manual says to replace the bladder tank. 

WP_WT-P_WM-P_GX2.pdf

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I have the same pump, with the same issues. Our pump issues started after our tank ran dry one day. Kind of annoying but not a big issue. It probably has something to do with the pressure regulator or more likely the bladder tank. The manual says to replace the bladder tank. 
WP_WT-P_WM-P_GX2.pdf

Thanks Ahab, does your pump run constantly now even opening one tap or flushing a toilet etc ?

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Look at the rubber flap on the cisterns of your toilets if they are leaking like mine they cause the pump to turn on and off to compensate 🤔

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Look at the rubber flap on the cisterns of your toilets if they are leaking like mine they cause the pump to turn on and off to compensate

Thanks but I meant when a tap opened/ toilet flushes/shower running etc the pump runs intermittently and not constantly ( as I think it did before).

 

When no water is being used the pump stays off I.e. all night.

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Have / had the same problem and have isolated the problem to a couple of cheap plumbing fixtures.  Specifically any that mix hot and cold water at the discharge point.

 

The expensive shower fixture in the main bath does not cause a pulse, but the cheaper one in the guest bath does.  Replaced the cheap one and it's no longer pulsing.

 

But have noticed that the main bath fixture pulses if not opened fully, which leads me to believe these problems stem from lousy packing in the fixtures since the expensive one is showing it's age

 

I would try and isolate the problem before proceeding further  

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Have / had the same problem and have isolated the problem to a couple of cheap plumbing fixtures.  Specifically any that mix hot and cold water at the discharge point.
 
The expensive shower fixture in the main bath does not cause a pulse, but the cheaper one in the guest bath does.  Replaced the cheap one and it's no longer pulsing.
 
But have noticed that the main bath fixture pulses if not opened fully, which leads me to believe these problems stem from lousy packing in the fixtures since the expensive one is showing it's age
 
I would try and isolate the problem before proceeding further  

I guess that problem is related to the amount of water flow.
For example: a large shower head will call for a larger volume of water causing the pump to run constantly whereas with a cheaper/smaller shower head the volume will be too much causing the pump to pulse ( on a few secs off a few secs).

This is where my question is based:

Should the pump pressure remain constant and pulse on and off depending on volume requirements ??

Or should the pressure adjust automatically to compensate for different volumes requirements and the pump run constantly ?? ( I guess that’s where the bladder comes in to adjust for varying volumes as in Ahabs post ?? ).

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This compact series of pumps are fitted with a tiny bladder tank and pressure switch with a close on/off differential (around .4 Bar). This can result in rapid cycling at low flow.

Be sure to release all air from the pump and around the house after draining.

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5 hours ago, Andrew Dwyer said:


Thanks Ahab, does your pump run constantly now even opening one tap or flushing a toilet etc ?

No it does not run constantly, but when it is running the pressure varies up and down. As soon as a faucet or toilet is flushed the pump kicks on and runs until the flow stops (just the pressure is not steady).

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No it does not run constantly, but when it is running the pressure varies up and down. As soon as a faucet or toilet is flushed the pump kicks on and runs until the flow stops (just the pressure is not steady).

Ok thanks.

Can I ask you where you bought the bladder tank ?

That’s got to be the prime suspect as there is nowhere ( that I can see ) to drain water or air, only the hopper for priming, which I guess once it’s up and running is not necessary to mess with .

The pressure switch I’ve never touched so would be unlikely, IMO, that the pressure needs adjusting.

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1 hour ago, Andrew Dwyer said:


Ok thanks.

Can I ask you where you bought the bladder tank ?

That’s got to be the prime suspect as there is nowhere ( that I can see ) to drain water or air, only the hopper for priming, which I guess once it’s up and running is not necessary to mess with .

The pressure switch I’ve never touched so would be unlikely, IMO, that the pressure needs adjusting.

The bladder tank is very low capacity maybe 1 litre draw down at best. You cant expect a pump of that capacity not to short cycle on low demand with such a small bladder tank and up to 36L/min available. Its possible the bladder has lost some of its pressure and shortened the cycle a little. These small bladder tanks are often nitrogen filled have no service valve and are built to last.

 

You can add a larger capacity bladder tank to the outlet if cycling at low flow becomes annoying.

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Easiest is to adjust the pressure switch setting (with an insulated screwdrivers as others have said) a little so it shut's off at a slightly higher pressure (I.e. it'll keep running at lower flowrates - to suit your shower).

 

Need to ensure it still shut's off when all the taps are closed or the pump will never shut-off and damage itself... It can be quite tricky getting it set just right, especially if your electricity supply voltage is prone to variation (a lower voltage will make the pump run slower, and it will never shut off - and damage itself on no flow).

 

If the bladder tank does fail it'll cycle very rapidly (less than 1 sec).  You can easily add a little more surge capacity with a 2m length of 2" pipe mounted vertically with a valve at top and bottom to drain it occasionally... no need of a rubber bladder.

 

 

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15 hours ago, Andrew Dwyer said:

Now when showering I can hear the pump pulsing ( 3 sec on 3 sec off ) something I never noticed before, if another tap is opened or toilet flushes the pump stays on constantly.

I mentioned it to the gf , she said that now that the pump is on the steel frame it is louder ( which it is ) and nothing has changed. ( will also look at some rubber material to reduce the pump noise, steel frame has rubber feet).

 

It does seem logical that the pump delivers more water required for just the shower hence it turns on and off and stays constant when an additional tap open/toilet flushes calls for more water.

It is probably normal, if you get a shower unit that has a greater flow rate it will not happen.

 

Do ignore any suggestions to change the pressure switch settings, the will make no difference at all as it is the flow rate that is affecting the pump, also from the instructions IMG_7164.PNG.71fa087ad0de554c8fdfeb6c9b9bb6c0.PNG

 

You might possibly have a problem with the flow switch (life saver)

 

IMG_7163.PNG.a252df78df91fdbec7bb591acbd149e0.PNG

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