Hi, I hope someone can help me with two issues.

1. My house is 43 years old and has GI pipe up to the house from the toby on the footpath. I have to replace it all as it's blowing out and leaking. It was laid in clay. I have dug back from the toby, under 200 mm of concrete in places and under a block wall etc. It's been a mission, all right. I have come to a T joint on the east side of the house where all the plumbing is (laundry, kitchen, bathrooms, toilets etc). One lead goes under the house and would appear to come up through the concrete slab and into the back of a shower wall. The other lead goes a few meters to an outside tap which comes up through a concrete courtyard. My question is this: Can I safely assume that there is only one mains water supply into the house? I don't want to have to dig up the final few meters to the outside tap if I don't have to as the GI pipe is very deep below a raised garden bed. It's back breaking for a 60 year old.

2. Over the past 6-7 or so years the hot water flow has been getting weaker and weaker. I have had two plumbers in and one replaced the 7.6 mm APEX pressure reducing valve this week and cleaned the filter. No change. The second said that the 270 liter low pressure tank is mounted too high. previously, we had a real torrent of water in the shower. It's not scale build up in the shower head as when we run cold water to the bath or any other cold faucet the hot supply stutters and coughs and then just runs out completely at any hot faucet. Thankfully we still have enough hot flow for a shower, albeit a pretty low flow one. I have replaced 11 meters of GI supply pipe so far and it hasn't made any difference to the hot water flow. The question is, why is this happening?? One of the plumbers said I will have to go to a mains supply but nothing has really changed with the plumbing it's just that the hot is just getting worse and worse.

Thanks for reading all this stuff and if you need me to clarify just post away. Thanks, Mark, Christchurch.

Linkback: https://www.plumbers.nz/q-and-a-water-pressure/50/replacing-galvanized-pipe-main-supply-and-water-pressure/1380/

firstly have you eliminated any potential blockages in the hot pipework?

it may be required that you reverse flush the hot water system

also - please tell me you DO NOT have a hose acting as your hwc exhaust?!?

If the problem is just on your hot water side could it be that your hot water cylinder is over 20 - 30 years old? Anything attached to it?

"if the problem is just on your hot water side could it be that your hot water cylinder is over 20 - 30 years old? Anything attached to it?

The hwc was manufactured in 2000. I don't think there is anything "attached" to it except pipes carrying how water to faucets.

Hi Toycollector10,

There will be a point or multiple points where the gal pipe changes to copper. It could be that the cylinder is feed from the galv, at this point there will be a brass fitting. The galv and brass will have reacted, causing the pipe fitting to corrode internally and reduce the internal diameter. Check this fitting out.

What was the condition of the galv pipe you took out?


Don,t you hate it when you can't sleep!

So glad you got Peter Diver Plumbing in - they've had a rough time with the Mainzeal collapse.  I'm sure they did an excellent job for you.

Yes know what you are saying about Mainzeal, we have been caught too - for a lot of money.  Peter Diver Plumbing is a very reputable firm with a lot of staff.  Firms will be hurting all over NZ with his collapse and we haven't even seen the flow on effect yet of subbies falling over, merchants taking hits and jobs with no guarantees on them now the company has collapsed.  I understand liquidators have now been appointed and I for one will be bloody interested to see if the Directors have done anything dodgy, given that Mainzeal were still handing out new contracts for jobs a couple of weeks before they went belly up.  I find it very, very hard to believe that Shipley and Collins didn't have an inkling that things were going pear shaped, they sure did a few days out when they resigned.  The rest of us had to put up with shitty emails telling us were weren't getting paid but they would keep us updated, not as updated as www.stuff.co.nz did though when they announced the collapse on Waitangi Day.  Someone needs to pay for the mismanagement and someone needs to pay for stringing subbies along for so long and not being honest. 

$240 - sounds like 2.5 to 3 hours labour and a part....  Was it after hours on the 24th?  Probably someone who had knocked off for Christmas.  It's times like this that the bigger firms always have someone on call - still it pays to have a regular plumber and stick with them - the service will be good and they will know the little foibles of your property.

Good luck