Water leak issue

[Mikey]

We had a similar problem in a house in FL; aggressive soil ate pinhole leaks in the unprotected copper buried under the slab. Re-plumbed the entire house overhead.

 

[Diehard]

Hadn't thought of a leaking mixing valve, but the pressure from the water heater and city water on the cold side should be the same, right? So I don't get how warm water could leak into the cold water side. I also don't get how a leaky toilet could be related. Unless again, you're saying the hot side is leaking into the cold side somehow.

I suppose it's possible for the hot to go into he cold when the cold water is used at a Hot/Cold faucet if the cold water pressure drops. But I'm not too sure it would drop lower than the hot water side.
Still no answer on whether it may be coming out the TPR valve. It's possible Geekfather didn't know what a temperature/pressure relief valve(TPR) is.

 

[Mikey]

I suppose it's possible for the hot to go into he cold when the cold water is used at a Hot/Cold faucet if the cold water pressure drops. But I'm not too sure it would drop lower than the hot water side.
Still no answer on whether it may be coming out the TPR valve. It's possible Geekfather didn't know what a temperature/pressure relief valve(TPR) is.

It's called a "plumbing crossover". Many articles about it on the Web, looks like a common problem in commercial settings. I had heard about it in residential use, but never experienced it personally.

 

[Diehard]

It's called a "plumbing crossover". Many articles about it on the Web, looks like a common problem in commercial settings. I had heard about it in residential use, but never experienced it personally.

Yes I do recall many of the commercial service sink faucets came with integral check valves. I suppose they were there for a reason.

 

[TomFOhio]

I don't think its going to mix water unless the valve is turned on. He has hot water running someplace with all the
faucets turned off and nothing leaking that he can see. He never did say whether he has any pipes going underground.

 

[Mikey]

As a last resort, he could call Sleuth.

 

[FishScreener]

I suppose it's possible for the hot to go into he cold when the cold water is used at a Hot/Cold faucet if the cold water pressure drops. But I'm not too sure it would drop lower than the hot water side.
Still no answer on whether it may be coming out the TPR valve. It's possible Geekfather didn't know what a temperature/pressure relief valve(TPR) is.

All too possible with single handle units, which now days is the tub/shower, lavatory and kitchen sinks. The seats wear and let water pass from one side to the other, without leaking out the tap.

But, I’m still guessing the tpv is weeping, and outlet from the discharge the line is hidden.

 

[frodo]

Geekfather

Please answer this question

is the relief valve on the water heater leaking water out of the end of the pipe that is attached to the relief valve?

 

[Mikey]

[QUOTE="FishScreener, post: 103021, member: 16377
But, I’m still guessing the tpv is weeping, and outlet from the discharge the line is hidden.[/QUOTE]
O the irony... there was a discussion recently on the forum about whether or not the TPR air gap had to a) exist, and/or b) be easy to see at the water heater.
https://www.plumbingforums.com/threads/hot-water-draining-out-of-outside-drain.13433/#post-101273

 

[frodo]

[QUOTE="FishScreener, post: 103021, member: 16377
But, I’m still guessing the tpv is weeping, and outlet from the discharge the line is hidden.

O the irony... there was a discussion recently on the forum about whether or not the TPR air gap had to a) exist, and/or b) be easy to see at the water heater.
https://www.plumbingforums.com/threads/hot-water-draining-out-of-outside-drain.13433/#post-101273[/QUOTE]

A air gap is required, It is required where the pipe indirectly connects with the sewer
It is not required or allowed to be installed any where else,
Back in the day, we used to pipe the pop off straight down to the WH pan, that was outlawed
due to someone getting burned

 

[Diehard]

Regarding the termination of water heaters TPR

It's all up to how the local inspector interprets it.

The intent of the requirement, however it may be worded, is that the possibility of back siphonage of a hazardous material is prevented.

 

[frodo]

608.5 Discharge Piping,

The discharge piping serving a temperature relief valve, pressure relief valve, or combination of both shall have no valves, obstructions, or means of isolation and be provided with the following:

(1) Equal to the size of the valve outlet and shall discharge full size to the flood level of the area

receiving the discharge and pointing down.

(2) Materials shall be rated at not less than the operating temperature of the system and

approved for such use.

(3) Discharge pipe shall discharge independently by gravity through an air gap into the drainage

system or outside of the building with the end of the pipe not exceeding 2 feet (610 mm) and not less than 6 inches (152 mm) above the ground and pointing downwards.

(4) Discharge in such a manner that does not cause personal injury or structural damage.

(5) No part of such discharge pipe shall be trapped or subject to freezing.

(6) The terminal end of the pipe shall not be threaded.

(7) Discharge from a relief valve into a water heater pan shall be prohibited.

Their is no alternative interpretation a T&P drain connects to the T&P with a male adaptor and the piping is run to a floor drain or floor sink with an air gap at the drain.
OR it can run out the building and drain on the ground,
it can not drain into the pan, nor tie into the pan drain,

 

[FishScreener]

The plumbing section of the International Residential Code, adds that the discharge should located so as to be visible to residents so they can detect leaks.

On my housing units I’ve started having a two inch drain line immediately below the tpv discharge line, the two inch runs through a trap filled with mineral oil to the main stack.

 

[TomFOhio]

Looks like were more worried about this man's leak than he is. Where's he at????? Has any of these suggestions helped???

 

[Diehard]

Their is no alternative interpretation a T&P drain connects to the T&P with a male adaptor and the piping is run to a floor drain or floor sink with an air gap at the drain.
OR it can run out the building and drain on the ground,
it can not drain into the pan, nor tie into the pan drain,

Not to belabor the point, but if you look back at the link you provided in post #30 above, I believe you and Mikey had some differences in interpretation. (Post 12 through 15)

I'm not disagreeing with what you just posted in the 4 lines of text above. Just the part about, There is no alternative interpretation.

 

[Mikey]

@Diehard: I think you believe correctly. The neat thing about most codes is there is always an alternative interpretation. The only interpretation that always works is "when in doubt, ask your AHJ." I'll bet, however, that you could find AHJs around the country who would agree with Frodo, or me, or both, or neither.

 

[Mikey]

And, back on topic, I coincidentally have a hot-water-leaking-into-cold-side issue going on right now. Haven't investigated it yet, but it follows some re-plumbing of two bathrooms completed last week by professional plumbers.

 

[Diehard]

@Diehard: I think you believe correctly. The neat thing about most codes is there is always an alternative interpretation. The only interpretation that always works is "when in doubt, ask your AHJ." I'll bet, however, that you could find AHJs around the country who would agree with Frodo, or me, or both, or neither.

I've dealt with many inspectors over the years, regarding plumbing and cross connections control, in many different states around the country. In one case I had to send the guy back to his boss, he was so far off in his ideas.

 

[Richard Gavle]

I have seen a few furnace humidifiers plumbed to hot water.

 

[Mikey]

I have seen a few furnace humidifiers plumbed to hot water.

Don't know if it's code or not, but it doesn't make much sense, unless there's provision for making sure the "hot water" is in fact hot at the time of use.