Thread: water heater T&P drainage line

We had the new water heater installed around 1 & 1/2 yr ago without knowing the updated building code. What kind of problem would we get if the T&P line with no fall, instead of curve. According to a plumber, it would cause the water heater to blow up or leak. Is this true or he simply wants to rip us off? Attached is the picture of it.

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The installation is wrong.
Refer to the manufacturers installation for specifics on the installation of the water heater and the configuration of the drain for the T&P relief. The installer should have left the instructions with the unit. Attached is an installation illustration from one manufacturer.

Thank you Alton. The question is would this cause the water heater to blow up or leak?

Yes, it could blow up.

Thank you Rick. That's kind of scary but what's the possibility? I can understand if the drainage line is clogged. If you look at the picture again, even though the drainage line is not straight down but it does go outside the house to release the pressure. Isn't it the main purpose is to release the pressure?

Originally Posted by betterhome

We had the new water heater installed around 1 & 1/2 yr ago without knowing the updated building code. What kind of problem would we get if the T&P line with no fall, instead of curve. According to a plumber, it would cause the water heater to blow up or leak. Is this true or he simply wants to rip us off? Attached is the picture of it.

Originally Posted by betterhome

Thank you Alton. The question is would this cause the water heater to blow up or leak?

Originally Posted by betterhome

Thank you Rick. That's kind of scary but what's the possibility? I can understand if the drainage line is clogged. If you look at the picture again, even though the drainage line is not straight down but it does go outside the house to release the pressure. Isn't it the main purpose is to release the pressure?

Mr./Ms. "betterhome":



THE PICTURED IS DANGEROUS AND HAZARDOUS! WARNING!! DANGEROUS CONDITIONS WHICH MAY LEAD TO INJURY, DEATH, AND property damage!!

The TP&V valve pictured still bears (as it should) its Manufacturer's WARNINGS tag. This tag includes the DANGER warnings regarding this critical device - including the DANGER warnings regarding TRAPPING the DISCHARGE from the Safety Valve. YOU ARE ABSOLUTELY WRONG in your characterization of the "line" as "drainage".

The output from this (Temperature and Pressure Relief Valve) SAFETY device is DISCHARGE. The safety device is COMPROMISED as is the storage-type water heater! It is NOT drainage unless and untill it has been exposed to atmosphere, and DISCHARGED to an OPEN and indirect receptacle, floor, atmosphere.


There is so much WRONG with your UNSAFE, DANGEROUS, HAZARDOUS, and COMPLETELY WRONG installation of your big box waterheater acquisition any Utility employee, licensed plumber, or employee of an authority having jurisdiction, would RED TAG the installation, and likely lock out your gas supply and (at least temporarily) restrict any occupancy. The entirety needs to be SHUT DOWN NOW.

DANGER! Dangerous & Hazardous to LIFE and Property.


It is obvious this installation is unqualified and unpermitted/inspected. It is a HAZARD. The WH should and would be taken out of service until the HAZARD is eliminated. The TP&V should likewise be inspected/tested, and frankly at this point removed & replaced by a professional licensed plumber under a plumbing contractor entity as its reliability, potential sediment scaling especialloy with your regions "water issues", etc. and its history of IMPROPER installation makes its proper operation questionable and voids its warranty from the manufacturer.

The HAZARD also makes the history, integrity, etc. of the WH itself questionable and would have voided any manufacturer's warranty as the installation pictured is contrary to the manufacturer's instructions, the ANSI standards etc. and every model code in existance. Most importantly the device (T&PRV) has been compromised by the installation and is in violation of the manufacturer's instructions, the standards of safety for the NECESSARY and REQUIRED SAFETY DEVICE, etc.

The violations and more importantly the HAZARD, is unjusitifiable, inexcusable, and unconscionable.

The pictured is a DANGER to LIFE and property.

The expansion and force of a steam flash is on the scale of a nuclear bomb.

The corrugated copper water connector and threaded adapters you've employed are completely and entirely UNSAFE, DANGEROUS and HAZARDOUS as well as being completely illegal.

Libility is HUGE and not just civilly, especially should anyone be injured or DIE due to GROSS Negligance, DANGEROUS AND HAZARDOUS installation, complete and total disregard for each and EVERY WARNING CLEARLY shown upon the equipment(s) installed as pictured.

P.S. Expect your topic discussion will be moved to the "Questions from Home Owners, Home Buyers and DIYers" Subject area of InspectionNews.net in the very near future.

I know my post immediately above is HARSH, it is meant to be, because it NEEDS to be (especially due to the self-justifying replies by the OP to others' replies). There is NO justification for the installation IT IS DANGEROUS AND HAZARDOUS.

The WH and the TPRV are now in question, they have both been exposed to potential conditions of operation which compromise the integrity and safety, and the warranties of essential, CRITICAL operational standards. The entirety MUST be SHUT DOWN NOW and the systems MUST be inspected and remediated by a PROFESSIONAL.before ANYONE or ANYTHING is exposed to the HAZARDS this installation as pictured provides while in operational or standby mode and connected to the fuel gas supply system.

Originally Posted by H.G. Watson, Sr.

...

The expansion and force of a steam flash is on the scale of a nuclear bomb.

And with that statement you have lost all credibility on this subject.

Originally Posted by betterhome

Thank you Rick. That's kind of scary but what's the possibility? I can understand if the drainage line is clogged. If you look at the picture again, even though the drainage line is not straight down but it does go outside the house to release the pressure. Isn't it the main purpose is to release the pressure?

The only time it will be a problem is if the TPR is called into action and it releases. It is possible for that to happen at any time but it is not probable.

That is a GE water heater that came from either Home Depot or Lowe's, if they are the ones that contracted for it to be installed you need to call and file a complaint. Tell them they have installed a potential bomb in your home and you want it corrected.

If you did it yourself then you need to take care of it. It is a simple repair that will cost you less than $20. FYI, just terminate the line no more than 6" from the floor, do not try to go back through that wall with it.

Hi H.G.,
It might sound like I am trying to justify the case but I am not. Even though I am hoping to hear this is just a minor thing but I want to learn what's the real issue is by asking questions. I don't take it as personal attack or too harsh on me but rather appreciate your and others honest opinion and insight. I am glad to have someone like you on this forum and am more than welcome to any expert advices.

Hi Scott,
Also thanks for your suggestion.


Here's my other thought, I do understand unless both thermostat and T&P valve fail at the same time then the WH will explode when the pressure builds up. However, if there's a way for the pressure to escape then I kind of doubted explosion would come into place. Any further comments on this?

Originally Posted by betterhome

Thank you Alton. The question is would this cause the water heater to blow up or leak?

As others have said, yes. In it's present configuration there is a possibility of a catastrophic failure of the pressure vessel. Visit the "Mythbusters" site on discovery.com and search for "water heater explosion". There are a couple of videos there that will illustrate what can happen if the T&P valve fails.
Plumbing the T&P discharge in a manner such as your present unit could very well contribute to such a failure to operate. Perhaps it is not likely, but do you want to be person that the unlikely event occurs to?

Bottom line is that the installation is wrong. It is a very real safety concern and should be corrected. Obtain the manufacturers installation instructions and have the installation done to that standard. Your plumber has told you that it is a problem. Several here have confirmed that safety issues exist with the installation.
I see that you are in Texas. I am sure that in your area there are wasps that like to build their nests inside pipes and equipment of the like. We call them dirt daubbers in Arkansas and they build a very densely packed mud nest that will block the discharge tube if they decide to nest there, all that is needed after that is an issue with the tstat.
We tried...

Originally Posted by Alton Darty

...videos ... that will illustrate what can happen if the T&P valve fails...

Kiss your butt goodbye.

Originally Posted by Scott Patterson

That is a GE water heater that came from either Home Depot or Lowe's,

FYI:
GE standard Water heaters are an exclusive to Home Depot.

If you did it yourself then you need to take care of it. It is a simple repair that will cost you less than $20.

Agreed, or just pay a plumber to fix it, it should cost less than $100 in most areas.

Dom.

Originally Posted by John Arnold

And with that statement you have lost all credibility on this subject.

It is true. The shock wave velocity is similar as it overcomes and exceeds the initial detonation hydrodynamic front, at approximately the speed of sound in air at approx. 1050 ft./sec. as it is with all explosions.

Read: "A Boiler: The Explosive Potential of a Bomb" (which actually focuses and goes into detail in the discussion of and discusses storage type water heaters in "closed" circumstances).


NationaBoard News

Older version and faster loading same article above:
NationaBoard News



Read:

MECHANICS OF AN EXPLOSION
Presented by Richard E. Jagger, Assistant Director of Inspections,
The National Board of Boiler and Pressure Vessel Inspectors,
at the National Board's 53rd General Meeting,
Charlotte, North Carolina, on April 24, 1984.

at:
MECHANICS OF AN Explosion

begining at "a vapor explosion"

Temperature And Pressure Relief Valves Often Overlooked:
Temperature And Pressure Relief Valves Often Overlooked

Water Still Flashes to Steam at 212...
Water Still Flashes to Steam at 212

Residential Water Heater Safety:
Residential Water Heater Safety


Temperature of saturated steam | Industrial hoses


You might also try actually reviewing the entirety of the installation as pictured by the OP and the entirety of the posts you selectively quote before you stick your virtual foot in your virtual mouth.

Originally Posted by H.G. Watson, Sr.

It is true. The shock wave velocity....

Yes, that's all very interesting. I certainly hope we aren't selling any water heaters to Iran.

My point, of course, has nothing to do with shock wave velocity. In the context of the OP's question and concerns about his water heater, it is ridiculous and absurd to make comparisons to nuclear weapons, and when you do so, it makes the rest of your comments suspect.

I skimmed through the posts above and didn't see anything about the sediment trap which is missing.

A sediment trap is required to be installed after the shut off valve and before the appliance.

Both that and the proper drain line for the T&P relief are critical, and both, under different but critical conditions, can lead to serious injury or death ... which is why both are required by the code.

While Watson does provide much good information, he mostly blows things way out of proportion, then spends a lot of effort trying to defend himself as he keeps getting sillier and sillier in his responses trying to defend his statements. Sometimes it is fun to watch, but most of the time it is just boorish to have to endure.

Originally Posted by Jerry Peck

...
While Watson does provide much good information, he mostly blows things way out of proportion,....

Yes. The "good information" tends to get lost in the avalanche of non-salient and extraneous blather. You know the old saw about asking a man what time it is and he tells you how to make a watch... That's all well and good if want to know how to make a watch, but sometimes, most of the time, you just want to know what time it is.

To stop the debate here is a video of what actually happens when one of these things actually blows off.

Mythbusters Water Heater Explosion - YouTube

Originally Posted by champainspectionnews

To stop the debate here is a video of what actually happens when one of these things actually blows off.

Mythbusters Water Heater Explosion - YouTube

Yep. I tell clients about that video all the time. It's just too bad they edited out the mushroom cloud. I guess they thought it was scary enough already.

Betterhome, how goes it. Your instink was to ask the question and they were good to guide you. Something inside told you to ask it and these guys here are a pretty good source of info. Play it safe and have it corrected, no one wants you or any family hurt. Get er done and get er done fast. Good luck.

Rick

It is possible that the low spot could collect water and freeze or collect sediment and become otherwise blocked. A blocked relief line would allow the heater to have a catastrophic explosion if there was something to cause excessive pressure, such as a failed gas valve. It is also a violation of the mechanical codes. As is not following the manufacturer's instructions to install a drip leg in the gas line. I am interested in what type of piping you have on the water in and out. What is that?

Ignore it if you want... this homeowner/renter did...

Home's water heater explodes, hurtles 135 yards

Interesting discussion. Bottom line is (a) does the installation meet code(s) and (b) whether or not (a) is true, does the installation pass the Common Sense Rule - would a properly trained installer do the same thing in his Mother's house? Assuming you love your mother, the answer to both questions is "No."

Shut off the water heater, disconnect the corrugated line and replace it with a short, vertical (or downward sloping) length of discharge pipe (which meets local code) of the same size as the T&P valve outlet and which terminates, unthreaded, no more than 6" above the floor or drain. If you insist on keeping the current DIY set-up, provide a 6" air gap between the bottom of the discharge line and the top of a "collector" which drains to the outside. Even with the homeowner (or your wife) looking over your shoulder, this is, at most, a couple hours work and will satisfy most codes as well as provide peace of mind.

Sometimes it's important to take a step back and consider why we have codes (rules) in the first place - or rather, why the initial rules were developed. Contrary to popular opinion, it is not to set up a HI or BI as tyrant within your castle walls. It should be to protect the greatest number of people (and property) from the unintended consequences of their own ignorance - not stupidity. As most of us know, ignorance is curable through education or self study. Stupidity is hereditary and incurable.

In a prior life, I was an inspector (as we were known in the days before big offices and fancy titles) for a large insurance company. Once or twice I had a chance to inspect after a boiler explosion. Inspection was straight forward as very little stood between me and what remained of the boiler and its surroundings. Many of us can do all sorts of fancy calculations to demonstrate how much "explosive force" can be generated by a given amount of water heated to a given temperature and confined by a given force or structure. The rest of us can watch the You Tube video.

However, for all practical purposes, a domestic hot water heater is not going to explode unless its T&P valve is defective, corroded shut or somehow blocked or valved off. In the very low probability, but very messy aftermath of a steam explosion due to one of those eventualities, whether or not the T&P valve discharge line "met code" is not going to make a bit of difference in the nightly news photos.

The valve is meant to let the user know if the valve is leaking hot water - more than 210 degrees F (99 C for you folks outside the U. S. of A.) or more than 150 pounds per square inch gauge (1 megapascal?). If it's valved to the outdoors or directly to drain, the user can't know that the T&P valve is leaking and the system needs to be checked to discover why this is so. If the T&P valve is defective, etc. it won't matter if it runs up hill or down hill, into a drain or directly out doors. Your steam powered rocket ship will be leaving momentarily and will be taking a lot of its launch pad with it.

That's why we (should) test the valve at least once a year to make sure it does release water when we "flip" the valve stem. And that's why some manufacturers recommend that the valve be physically removed and re-inspected every three years or so (although I frankly doubt this is done very often as a practical matter - HIs - is this a recommendation?). If the valve is "pissing" due to over temperature or over pressure it needs to be immediately serviced. Until it is serviced, assuming the discharge line runs to a drain (or "horrors" to the drip pan), the water discharged won't rot your pretty floor or wooden foundation. And if you've provided no air gap or the discharge runs directly out doors, chances are you are not going to notice if the valve has vented.

So. Is it likely that you will be ground zero for the Steam Town express with the referenced installation? No. Does it meet code(s)? No. Would you install it this way in your Sainted Mother's house? No. So replace it today and post the new installation on You Tube or the DIY Network. Going back to my nap now. Enjoy.