Water leak from a fitting under the house, what is it?

Forums › Home Workshop DIY › Water leak from a fitting under the house, what is it?

OrangePeel

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#171406 16-Apr-2015 21:15

Hi guys,

Was just under the house fixing a duct when I discovered a leak from our water pipe coming in from the street. There's some kind of T intersection in the pipe with water dripping out a small hole in the bottom. I'm wondering if this is a pressure relief valve of some sort since it doesn't seem to have anything connected to the bottom, and the hole the water is coming out of is only about 5mm diameter. Here's a blurry pic I took while I was down there:

Anyone got any idea what this is and why it would be dripping? Looking at the ground below it's probably been dripping a while.

Thanks!

Dynamic

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#1285868 16-Apr-2015 21:23

I suspect it is some sort of pressure relief valve as well. These have a washer I believe that in this case has likely to have perished or worn out.

In the past we have had small stones come through the pipes causing valves and washers to prematurely fail. Council of course won't be interested in paying the bill if this is the case!

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#1285878 16-Apr-2015 21:37

(I am not a plumber.) Looks to me also like a pressure reducing valve, but installed upside down. I don't think it matters much regarding function, however with the diaphragm at the bottom you might get issues with debris settling in it (as Dynamic said). All the photos I've seen of installations have it either pointing up or sideways, not down. You also see them with a strainer between the water meter and the pressure reducer. A strainer looks like a y-piece with one branch closed off, where debris is collected.

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cisconz

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#1285886 16-Apr-2015 21:55

Also, it should have a pipe running from there out to a drain, this is so if it is used, it wont flood under your house.

Hmmmm

gzt

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#1285887 16-Apr-2015 21:59

Hmm. Don't recognise it. Do you live in often below zero area? Might be some kind of expansion valve. No idea. Is it cold feed?

Aredwood

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#1285917 16-Apr-2015 22:57

That is an early design RMC pressure limiting valve. It is leaking from that hole in the bottom because it has failed. Replace it with another pressure limiting valve. And install a line strainer unless there is already 1 upstream. Also those old RMC valves often cause poor water pressure / flow issues.

I normally install Apex valves as replacements - NZ made. http://apexvalves.co.nz/pressure/pressure-limiting-valve/

OrangePeel

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#1285945 17-Apr-2015 06:47

Ahh good. I think I'll just get a plumber in then, I'm not experienced with copper pipe work.

We're in Wellington, so not really a below-freezing area. Pipe is cold feed, and I don't think I've seen a strainer upstream. The pipe disappears underground when it gets to the side of the house, and we don't have a water meter (luckily in this case!)

Thanks for your help everyone!

Jase2985

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#1285955 17-Apr-2015 07:24

cisconz: Also, it should have a pipe running from there out to a drain, this is so if it is used, it wont flood under your house.

but they dont drain the excess pressure, they limit it. there is only an input and an output to the valve, no drain

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cisconz

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#1285970 17-Apr-2015 07:59

Jase2985:but they dont drain the excess pressure, they limit it. there is only an input and an output to the valve, no drain

As the OP says, it is leaking.

Anything that has the potential to leak like that, should be being drained somewhere.

Hmmmm

Jase2985

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#1285989 17-Apr-2015 08:05

cisconz:
Jase2985:but they dont drain the excess pressure, they limit it. there is only an input and an output to the valve, no drain

As the OP says, it is leaking.

Anything that has the potential to leak like that, should be being drained somewhere.

yes leaking different to needing a drain fitted, the manufacture didnt seem to think it needed a drain.

what a poor excuse for an argument. go to where all your hot water system components are and see how many have drains because they could leak. non have drains but all could leak

it has a seal in it and its perished, it happens some times but it doesn't need a specific drain

Niel

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#1286068 17-Apr-2015 09:52

In South Africa a drip tray is installed under cylinders to catch any leaks. Sometimes the drain pipe is installed but not connected at the tray... We had that once, and the common location for a cylinder is in the ceiling space so we found out pretty quick when it leaked! (The old houses had cylinders installed over a baths, which is sensible.)

It seems NZ regulations are relaxed in this regard, just let it drain through the floor boards (or in the OP case, under the house where you don't see it). Our new build has a concrete slab and the pressure relief valve has an overflow pipe that goes to a drain, but it will be interesting when the cylinder fails one day.

Pressure limiting valves are common, it should be a relatively cheap fix.

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DarthKermit

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#1286140 17-Apr-2015 11:13

In old New Zealand houses, circa 1940's or earlier, they used to all have a header tank up in the attic (in the days before pressure reduction valves were invented).

I remember our house in Nelson had a header tank, sitting in the middle of a nice big drip tray.

I put a floor drain in our HW cupboard here after the cylinder started leaking a bit. It's since stopped leaking, but will need to be replaced one day.

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