Any plumbers out there?

[KeithB]

We have rotten water pressure. If someone is in the shower (we have two) and anyone flushed one of the three dunnies in the place, the person in the shower gets scalded.

Sydney water says we should be getting 18ltr/min at the front tap, which we are. In fact we get 27 ltr/min. The static pressure at the front tap is 43psi. But when I turn on a couple of taps inside, it drops to 21 psi. The house is 25 years old and has all copper plumbing.

Question: is the town supply at fault or is our internal plumbing on the fritz?

Thanks in advance.
Keith

[austastar]

Hi,
    Have you tried turning the dunny flush water tap to about a quarter of the present flow?
It will take longer to fill, but may spare the shower occupant some strife.
Cheers

Sent from my GT-N5110 using Tapatalk

[rags]

Hi Keith
Being from a generation were I learnt my trade using both metric and imperial and I know we still like to talk pounds and inches but I will talk metric as that is what we do today.

Although Sydney Water (SWC) only have to deliver water at 150kpa your 43psi would equate to around 290kpa so SWC  have meet and exceeded their customer contract. They will tell you that 150kpa would equal approx 18 lt run per minute but they haven't had any technical staff there since 2010 when they were no longer required (like me). Your approx 300 Kpa is adequate for a plumbing system but not exceptional. In saying that by today's standards the internal fixtures of a house cannot exceed 500kpa or 9 litre/min.

What we don't know about your plumbing is what size your pipes are and what size and length are the branch runs. This can have a significant impact on how your water is delivered at each outlet and the simultaneous demands. 1/2" pipe on the cold supply should not exceed 3metres and a 1/2" branch should only be taken off a 3/4" main line.

What type of water heater have you got, instantaneous or storage?

I'm guessing the water heater cold water feed is only 1/2" in size ( sorry just went back to imperial for pipe sizing) which is inadequate for anything less than a single point heater. The manufacturer puts a 3/4" connection on most heaters for a reason but plumbers in an effort to save $ will under-size the heater connections pipes and fittings. The hot pipe leaving the heater should be at least 5/8" to first branch, then 1/2" may be ok.

Also one other contributing issue maybe water efficient tapware with restrictive aerators on tap outlets. Removing these from shower roses can help but water usage increases.

May not be much help but it is a start.

[KeithB]

Thanks Rags, I appreciate that.
It's the cold water that dies in the bum whenever any tap it turned on. We didn't have the problem when we bought the house 12 years ago. It seems to have crept up on us, maybe after we had a new storage water heater put in. I might have to go on a pipe inspection.
Many thanks,
Keith

[Cruiser 105Tvan]

If you find any Gal pipes under the house, they'd be my first choice as the culprits.
The Gal. on the inside gets worn away and the steel wall exposed and starts growing, reducing the inside diameter of the pipe.
They look ok from outside, but when you open a join, they're almost blocked.
Be worth checking back as far as the water Meter too.

[GBC]

I live fairly high up a hill so the head pressure from the tank on the next hill is pretty sad. I asked my plumber this week about in line pumps. He is making enquiries. If I turn up anything worthwhile i'll post it up.

[KeithB]

I considered this GBC, but wanted to make sure our pipes were in order first. Grundfos make great pumps and have several for mains pressure water boosting. I haven't priced one. But from other Grundfos pumps I have used over the years, they won't be cheap/ Here's a link:
https://au.grundfos.com/products/find-product/scala2.html

[WilSurf]

We had a similar issue in our previous house.
One tap on no issues, turning a second tap on pressure reduced significantly.
We had to change the pressure valve in the hot water heater and all problems solved.

[tryagain]

My bet would be on something blocking the flow somewhere, ie the pressure builds up to that of mains but as soon as you turn a tap on not enough water can get through to maintain your pressure, I'd be pretty sure that the issue is your side of the meter but a chat to neighbours to see if they have the same issue to check might confirm.
We had a similar issue with our showers and the water temperature a while back, I think what was contributing to it a fair bit was that the HWS had a pressure reducer on it but the cold line didn't which resulted in a big pressure difference as well as water saver heads which restrict the flow and allow pressure to build up to that of the feed, this meant that if someone even thought about turning a tap on when someone was in the shower the temp would change dramatically. might be worth taking the flow restrictor discs out of the shower head and see if that makes a difference as well.

Sounds like you have a restriction in your flow somewhere to me.

[KeithB]

I just pulled the shower hand held thingy off, ran the tap and got a huge jet of water. So I went down to the hardware store for a new hand held thingy. But the best they has was 6.5 l/min - which is two thirds of a bucketfull per minute. Bugger that. So I came home and had a good look at it and, lo and behold, there was a little plastic flow restrictor doover where the flexible hose screws in to the base of the hand held thingy. I took it out at wham! A terrific shower.

My wife is very proud of me, at least for the next half hour. I'll still check the pipes though.

Many thanks to everyone.
Keith

[Troopy_03]

I'm not a plumber, but I've got a visible crack while working, does that qualify me? 

[prodigyrf]

Fleabay used to have round screw on fine hole shower heads like this hand held one and they're great without a restrictor in them as the women like to flay the skin off their back for hours-
https://www.ebay.com.au/itm/Shower-Nozzles-Hand-Held-NEW-Ultra-Thin-Pressure-Boost-30-Water-saving-Sprayer/253645993491
There's also similar square hand helds -
https://www.ebay.com.au/itm/300-Hole-High-Pressure-Water-Saving-Handheld-Bathroom-Shower-Head-Nozzle-Tool/232348614883
but it seems the round screw on heads have disappeared in favour of lots of hand held ones with filter beads in the stem but you might like to try a micro hole head to see how they go with your pressure as they're great on mine and keeps her indoors happy now princess has departed. Sheesh don't you notice the utility bills drop when daughters decide to practice their intergalactic space invader art on some other poor earthling?