Necessity of Vacuum Relief Valve - Not Pressure Relief Valve

[tom12]

jadnashua, thank you for your post ref. New England code req's.
Do you have any diagrams or pics of approved N.E. installations with both fittings in place?
I ask because diagrams and pics on the web show all manner of confusing arrangements where tempering valves are installed in residential situations.
I'm going to post a new/separate message about this tempering valve business.

[hj]

quote; siphonage, as i understand it, is suction and gravity at work

Suction is a function of gravity AND air pressure. Water falling down, in a closed space, creates a loss in pressure. If there is no way for air to get into the chamber, a negative pressure, aka a vacuum, occurs, but siphonage does NOT occur. If air can enter, then depending on the dynamics of the chamber, the liquid either drains, or if it is part of an inverted "U" shape then it is siphoned out until it reaches a level where air can enter and break the flow. This point is either the "anti siphon" hole or the bottom of the siphon tube. In all cases, air entry is required to enable the system to reach an equilibrium. The vacuum relief valve is installed at the highest point in the system. Tempering valves can be installed anywhere they are needed. Hot in on one side, cold in on the other, and the tempered water out of the center to the system. They are installed anywhere you have access to all three lines.

[jadnashua]

jadnashua, thank you for your post ref. New England code req's.
Do you have any diagrams or pics of approved N.E. installations with both fittings in place?

I'm away for a couple of weeks, I can take a picture of mine when I return. Note that this is a CITY requirement, and maybe not a state one, as I understand it, but have not checked the state codes.

[tom12]

Thank you both for replying. hj, i will answer in a while.

[Nail24]

I just had a vacuum releif valve fail and allow water to flood the house. Has this happened befopre and if so what causes the failure?

[LLigetfa]

...what causes the failure?

A closed system without expansion tank or waterlogged tank could expose it to extreme pressure causing the failure. The TPR valve is meant to relieve pressure, not to save you from flooding, but rather to save you from an untimely death.

[Nail24]

t
This is the first vacuum valve I've seen installed. How didi we ever survive so long? I've got a pressure relief valve on the heater for over pressure. The only benefit I see in this is to give the cleanup industry a job. I fail to see how a collapsing tank could injure anyone.

[Nail24]

I just looked at some photos I took and discoverd the the vacuum relief valve is installed below the cold water feed line into the tank. I believe this is incorrect which would not allow an airpocket to be at the valve thereby causing a failure.

[master plumber mark]

t
This is the first vacuum valve I've seen installed. How didi we ever survive so long? I've got a pressure relief valve on the heater for over pressure. The only benefit I see in this is to give the cleanup industry a job. I fail to see how a collapsing tank could injure anyone.

It is very stupid, extremely stupid, and in 99.99% of all homes its not necessary , and like you have stated, its only gonna cause huge floods and make work for the flood disaster folks......

this is just more red tape and government interference into something they dont have a clue as to what they are talking about.. They have been trying to jump start the economy for the last 5 years and have failed.......,

so now lets try making more work for the clean up industries and
all the other trades that will have to come along to repair these disasters....

if this jump-starts the economy going from the bottom up, who am I to
argue with the brilliant folks making the rules ???

again, you have a better chance of hitting the power ball twice in your lifetime
than ever having a water heater implode in your home..

[master plumber mark]

Nail24

DIY Junior Member

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Posts3

I just had a vacuum releif valve fail and allow water to flood the house. Has this happened befopre and if so what causes the failure?
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So how many thousands of dollars of damage did it do??

Your plumber did not do due-dillagence when he installed your water heater....... there should have been a discharge pipe installed onto the valve and piped down to a drain like the t+p valve shown in the picture does...

did your plumber install the water heater in a Pan to catch any run off water?????.

if you scream and holler enough, maybe the plumber who installed this without somehow piping a discharge pipe to a DRAIN for you will have to pay for all the damages to your home..$$$$ ..

The possibility of it causing a flood was staring him right in the face... so dont you think he should be held liable for the damages to your home. .

to resolve the problem, just go to Lowes and get yourself a 3/4 galvanized plug and install it in place of the part that just flooded your home. or it will probably happen again....

the failure was caused because someone did not go the extra mile and install some kind of drain onto that vaccuum breaker,,, he probably should have extended the pipe over and installed the valve on the end of an elbow pointing down-wards.. so a cup and drain could have caught any flood waters


you will probably notice that the T+p valve has a pipe going down to the drain, because that can flood your home.......

So good luck ...have fun going after the plumber..

Your plumber will probably argue with you that he installed
the heater up to TO CODE...
Then you can argue back that he is the professional that should have known better. and HE should have somehow ran a drain pipe off of that vaccuum valve down to a drain to protect your property...

[Nail24]

Won't go after the plumber. He's just complying with what the idiots that aren't plumbers are making him do for the glorious "CODE". Insurance it the issue here. If they find that I have not complied with the "CODE" they walk away even if compliance is going to cost them $60,000.00 in damage. This i the pinacle of insanity.

[LLigetfa]

Being that it is a vent, it could conceivably suck in sewage if improperly connected to a drain. It would need a proper air gap.

[master plumber mark]

Won't go after the plumber. He's just complying with what the idiots that aren't plumbers are making him do for the glorious "CODE". Insurance it the issue here. If they find that I have not complied with the "CODE" they walk away even if compliance is going to cost them $60,000.00 in damage. This i the pinacle of insanity.


this is what I am talking about......

it should be taken to a drain with an air gap like in the picture...

So.....How much damage was done to your home????
and how happy is the insurance company about all of this??


Eventually, after the insurance companies have to pay for huge water damage losses,
they will send their lobby folks to congress and spread the money around
to get the laws and codes on this reversed of changed

Remember when they made water heaters more fire safe back in 2003?
the reason that was forced through the law books was the fact that water heaters
were the cause of many fires throughout the USA.. and the insurance companies
forced the water heater companies to make a safer water heater....
Creating FVIR water heaters actually a good thing with common sense reasons
behind the modifications....


when the insurance companies see a trend of floods and begin to bleed money,
they will insist on this stupid code to be removed ..

[hj]

Vacuum relief valves are "end line" valves, so there is absolutely NO WAY to install a "drain line" on them. They are also rated for 150 psi working pressure, just like most other plumbing items, so the T&P valve would not have allowed them to be "overpressurized". There are several reasons it could have failed, but only an inspection of it could tell for certain. Many of them contain a "spring loaded" ball and are installed vertically.

[Nail24]

As you can see in the photo this one was installed horizontally. Is that incorrect? Shouldn't it be installed so that it will have an air pocket that is compressed to hold the valve closed rather than water?