low water pressure

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1cloud

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#240218 27-Aug-2018 11:38

have a situation here and hopefully our gz pro can suggest something.

our property has a low water pressure problem (this is a main pressure house) as soon as any tap was turned on the pressure drops to 20 kpa. Plumber replaced the limiting valve and no hope. He suggested the pipe from meter to the valve maybe crimped, or could be debris or matter blocking the flow.

what are the chance something block it or crimped?

thanks

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#2079647 27-Aug-2018 12:12

I'm not the pro but if you have an old galvanised iron pipe it could be almost blocked with rust. I've had that in the main pipe and a smaller pipe to the header tank. Pressure is ok but you can't sustain any flow. If you do have to replace the pipe the plumber might tell you where you could dig a trench if costs are an issue.

mdf

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#2079654 27-Aug-2018 12:19

What Bung said. We've replaced a galv pipe with a blue flexi one. Night and day difference between the two.

Aredwood

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#2080036 27-Aug-2018 23:25

Check pressure and flow at water meter outlet. To confirm if problem is with watermain or on council side.

Assuming council side is ok - new watermain.

kryptonjohn

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#2080059 28-Aug-2018 08:38

Aredwood: Check pressure and flow at water meter outlet. To confirm if problem is with watermain or on council side.

Assuming council side is ok - new watermain.

And if you can't get at that, you may have a garden tap on the pipe before it goes into the house - that is before the pressure limiting valve - see what the flow/pressure at that point is.

1cloud

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#2080063 28-Aug-2018 08:55

kryptonjohn:

Aredwood: Check pressure and flow at water meter outlet. To confirm if problem is with watermain or on council side.

Assuming council side is ok - new watermain.

And if you can't get at that, you may have a garden tap on the pipe before it goes into the house - that is before the pressure limiting valve - see what the flow/pressure at that point is.

plumber tested at the side of house was stable at 500kpa , as soon as the front tap was opened it droped to 20kpa. He removed the limited valve and pipe straight through still the same.

what are the odds there were some debris in it? and this is a two years old house.

nickb800

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#2080066 28-Aug-2018 09:04

Seems unlikely that debris would lodge mid-pipe. Could be a kinked pipe then. I wonder if you can get someone (e.g. council?) with leakage detection equipment to locate the kink (should be noisy to their equipment). Otherwise you'll be digging it up.

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1cloud

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#2080072 28-Aug-2018 09:10

nickb800:

Seems unlikely that debris would lodge mid-pipe. Could be a kinked pipe then. I wonder if you can get someone (e.g. council?) with leakage detection equipment to locate the kink (should be noisy to their equipment). Otherwise you'll be digging it up.

we are thinking of next step.

kryptonjohn

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#2080075 28-Aug-2018 09:14

1cloud:

kryptonjohn:

Aredwood: Check pressure and flow at water meter outlet. To confirm if problem is with watermain or on council side.

Assuming council side is ok - new watermain.

And if you can't get at that, you may have a garden tap on the pipe before it goes into the house - that is before the pressure limiting valve - see what the flow/pressure at that point is.

plumber tested at the side of house was stable at 500kpa , as soon as the front tap was opened it droped to 20kpa. He removed the limited valve and pipe straight through still the same.

what are the odds there were some debris in it? and this is a two years old house.

Based on the typical static pressure and the immediate drop on flow, it seems that a crimp or other blockage is the only answer - assume that's what the plumber would have said? Bit of a pain.

1cloud

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#2080079 28-Aug-2018 09:20

kryptonjohn:

Based on the typical static pressure and the immediate drop on flow, it seems that a crimp or other blockage is the only answer - assume that's what the plumber would have said? Bit of a pain.

correct, and have no idea where it might be? and possible cutting holes of the wall to locate it

kryptonjohn

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#2080081 28-Aug-2018 09:25

1cloud:

kryptonjohn:

Based on the typical static pressure and the immediate drop on flow, it seems that a crimp or other blockage is the only answer - assume that's what the plumber would have said? Bit of a pain.

correct, and have no idea where it might be? and possible cutting holes of the wall to locate it

I would have thought the garden tap pressure drop shows the problem is outside the house (assuming the pipe to that tap is running from the meter box to the tap without going inside the house. If the house is new then maybe they bent the pipe too tight and it kinked - so would be looking at the pipe run from the meter to the garden tap where it has to change direction...

1cloud

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#2080083 28-Aug-2018 09:32

kryptonjohn:

I would have thought the garden tap pressure drop shows the problem is outside the house (assuming the pipe to that tap is running from the meter box to the tap without going inside the house. If the house is new then maybe they bent the pipe too tight and it kinked - so would be looking at the pipe run from the meter to the garden tap where it has to change direction...

same as inside taps, plumber said most likely would be inside the house.

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kryptonjohn

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#2080090 28-Aug-2018 09:46

1cloud:

kryptonjohn:

I would have thought the garden tap pressure drop shows the problem is outside the house (assuming the pipe to that tap is running from the meter box to the tap without going inside the house. If the house is new then maybe they bent the pipe too tight and it kinked - so would be looking at the pipe run from the meter to the garden tap where it has to change direction...

same as inside taps, plumber said most likely would be inside the house.

That doesn't make sense to me... Is the mains supply running from the meter box to the garden tap before entering the house? In that case the pressure would not drop at the garden tap if the problem was in the house.

Or am I missing something?

Bung

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#2080092 28-Aug-2018 09:48

1cloud:
same as inside taps, plumber said most likely would be inside the house.

Do you mean that the outside tap had poor flow as well or the garden tap was good but house bad?

Thinking of my own house i have Council tap at street then another shut off valve at house (to save having to trek out to street) and a mesh filter. Either shut off not fully open or filter blocked would affect flow.

1cloud

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#2080165 28-Aug-2018 10:41

Bung:
1cloud:

Thinking of my own house i have Council tap at street then another shut off valve at house (to save having to trek out to street) and a mesh filter. Either shut off not fully open or filter blocked would affect flow.

here is plumber report:

- The water pressure was tested at 75kpa at the hose tap by the rear ranch slider. This was a static pressure, with no taps being turned on.

- The pressure was tested at the hose tap at the side of the house. This was a static pressure of 500kpa, but this dropped dramatically to 20 kpa when the front tap was opened.

- The pressure gauges were then connected to the bottom toilet cistern connection.

- When the cistern tap was first turned on, the pressure was stable at 500kpa. As soon as any tap was turned on the pressure dropped significantly. This pressure drop also relates to the flow of water from the taps decreasing to a point where two taps cannot be used at the same time

- The water main has been traced from the meter to between the garages for #34 and the adjacent property.

- It is believed there may be a coupler in the ground at that point, but unable to verify this as there was a large amount of concrete slurry (left over from when drives or garages were concreted) in the ground.

Bung

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#2080181 28-Aug-2018 11:16

Not knowing the sequence of the build the original plumber could have been and gone before the garage was started. I wouldn't be surprised if the pipe was damaged then. It may be possible to bypass this area with another length of pipe.

If this is such a new build is it your problem?

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