Water Heater air release valve

[Bob from accounting]

Howdy,
I am trying to learn a bit about how to make it more convenient to release the air lock on a water heater when draining it.

1) Multiple plumbers have explained that it is not advised to be using the pressure release valve to do this which may break or cause ware and tear to the spring. I realize most people use this method with out issues however they spooked me on this method and want me to make sure it is intact and seated properly incase of emergencies. ( I realize this is debatable, to use or not to use when draining, but I am not in a position or comfortable to clash with their advise)

2) Opening up a faucet is not sufficient in my configuration and does not suck in air that well when draining, probably a height thing. ( I gotta say I do not like to hear the negative back pressure sucking in the tank.. Trying to act like its younger self as it sucks its gut in for a photo. When I hear that metal tank crunching in sound, I can't help but think of "Hunt for Red October" visions of submarines imploding on-themselves race through my mind, while ironically not realizing that Alex Baldwins career would eventually implode too. I digress.

3) Unscrewing the supply line up top I have noticed can put wear on those threads as I loosen and tighten over time. I have replaced the nipples and supply lines in the past and would prefer not to deal with thread wear of possible.

So this brings me to seeking a type of valve or configuration that is functional and safe, won't break the bank, something that goes up top. I saw this valve (click on blue link to see valve) but I am not familiar with it or what it is designed for which is why I am asking here seeking some help on a safe and functional way to conveniently allow air into the system when draining the water heater. Of course only if the 3 traditional ways listed above are not desired or possible. Also when I say safe, I would prefer not to just have some open ended ball valve up top that anyone can just accidentally open (Homer Simpson style) while still under pressure and rain down a fiery hell of scolding hot lava onto everyone in reach. DOOH

Thanks for your thoughts,
Bob

 

[Master Plumber Mark]

you are wise to just loosen the hot supply line on top the heater if you have flex adaptors..

the valve I seen in the picture would work ok if you really want to go to all that trouble

also, you will get yourself into troubles with those crappy vaccuum breakers that allow air into the
top of the heater to only drain this thing down once a year or so.....

I would just loosen the flexible supply line on the hot side. or just install a flex line to the
hot side of the heater if need be . and dont worry about it....

 

[Sponsor]

 

[Bob from accounting]

If this is not how you would do it, I get it, but any help on how one would do this would be appreciated. Just saves me the hassle of unscrewing these supply lines and water leaking out of them a bit. My faucets is below and are bad at helping drain the system. Thought I could get creative for 20 mins of labor and 20 bucks to make this go smoother each time.

 

[John Gayewski]

I actually don't think this valve will work. Any other ideas as to how to configure this? Again if this is not how you would do it, I get it, but any help on how one would do this would be great. Thanks again.

Dude use the relief valve. Unless your doing this daily it'll be fine. Think about this, the relief valve is a safety device. If it broke just from being operated then it's not much of a safety device device. They are supposed to be tested for operation regularly anyways.

 

[Reach4]

If opening one faucet is not enough, try two including the tub.

But I also see no problem with the T&P valve being used for this.

That said, why are you draining the WH? To flush? See https://terrylove.com/forums/index....o-flush-a-hot-water-heater.79444/#post-576623 post #7.

 

[Jeff H Young]

I don't mess with tand p. I don't test them unless a customer asks me to. then I tell them there is a good chance it wont shut off all the way. I avoid using old gate valves as well

 

[Sylvan]

Does anyone ever read the ASME codes any more?

A T&P and Safety and Relief valve has to be tested to make sure they will operate when needed.

TPR valve every 6 to 12 months. The more frequent the testing, the more quickly you'll spot potential problems and reduce the risks of costly water heater leaks or dangerous corrosion and mineral buildup within the valve

Also the T&P should be replaced every 3 years which very few people do

A few decades ago I testified in court how the boiler company was neglectful when they serviced the boiler but neglected to test the T&P while they were there.

It is not only common decency it can also lead to a lawsuit that the neglectful "tech" cannot win as a professional we are held to higher standards.

When I do my yearly boiler inspections It is good plumbing practices to check all the safety devices such as air compressors(*Safety) and relief valves (HW) and T@P

 

[Sylvan]

Boiler and gas inspections

 

[Reach4]

After I was told about a basement flood at a relative after the T&P stuck open on its own, I tested mine. I could not operate the lever, so I replaced it.

After replacing the valve, I saw there was debris in the unit, and I suspect that got there when I had operated the valve during a big cleanout I had done a few years before. I am glad I decided to test.

 

[Master Plumber Mark]

Does anyone ever read the ASME codes any more?

A T&P and Safety and Relief valve has to be tested to make sure they will operate when needed.

TPR valve every 6 to 12 months. The more frequent the testing, the more quickly you'll spot potential problems and reduce the risks of costly water heater leaks or dangerous corrosion and mineral buildup within the valve

Also the T&P should be replaced every 3 years which very few people do

A few decades ago I testified in court how the boiler company was neglectful when they serviced the boiler but neglected to test the T&P while they were there.

It is not only common decency it can also lead to a lawsuit that the neglectful "tech" cannot win as a professional we are held to higher standards.

When I do my yearly boiler inspections It is good plumbing practices to check all the safety devices such as air compressors(*Safety) and relief valves (HW) and T@P

I have seen relief valves probes covered with 1/4 inch of lime many times....
most people never touch them or replace them , and normally once you break that seal to allow water into the unit you might as well just change it out because it will
most likely start to weep from that day onwards..

I got a blown up water heater in my store front window from 1985 that the t+p never opened when it should have.... They really should be changed every 5 years or so
but people are just too cheap to pay for it to be done.......

 

[Jeff H Young]

Right Mark! they are too cheap . and If its not leaking and they don't ask about it I don't bring it up or if if I do see something I don't like I'll tell them that if I touch it it might mean it will need replaced right away

 

[Sylvan]

I was in Brooklyn Supreme Court three weeks ago and when the case is finally settled I will post what some moron engineer stated and how I proved his statements are erroneous as I cannot call him a liar or inept as that is considered liable

This case is about scalding and how the engineer stated "once the thermostat is set the temperature cannot rise higher"

I testified about stacking and how heat rises etc

I wonder why they call it a thermostat and not Aqua stat as it is a probe in water?

Anyone have any ideas?

 

[Terry]

I pulled a water heater the other day, noticed that the 6" galvanized nipple threaded into the T&P was almost closed off with rust.

 

[Breplum]

As to the OP (original post) question.
A Vacuum Relief Valve is exactly what you need and why they exist.
Watts LFN36-M1 is made for WATER HEATERS.
I quote:

About this item​

• Used in water heater and water tank applications to automatically allow air to enter into the piping system to prevent vacuum conditions that could siphon the water from the system and damage water heater or water tank equipment

 

[Weekend Handyman]

I was in Brooklyn Supreme Court three weeks ago and when the case is finally settled I will post what some moron engineer stated and how I proved his statements are erroneous as I cannot call him a liar or inept as that is considered liable

This case is about scalding and how the engineer stated "once the thermostat is set the temperature cannot rise higher"

I testified about stacking and how heat rises etc

I wonder why they call it a thermostat and not Aqua stat as it is a probe in water?

Anyone have any ideas?

So, what you are saying is the temperature would be what the thermostat is at that level in the tank, but hotter higher up and cooler further down?

 

[Sylvan]

So, what you are saying is the temperature would be what the thermostat is at that level in the tank, but hotter higher up and cooler further down?

Heat rises as we know and the T&P is usually on the side of the tank so again it does not "feel" the actual temperature at the upper most top

Using this reasoning we know the thermostat is near the bottom of the tank where the dip tube fills the tank with cold water . There could be at least 20 degree temper difference

This is the diagram I used to sway the jury and prove the engineer was an idiot when hew stated "What the thermostat is set for it never varies"

Stacking

Stacking

waterheatertimer.org

 

[Bob from accounting]

As to the OP (original post) question.
A Vacuum Relief Valve is exactly what you need and why they exist.
Watts LFN36-M1 is made for WATER HEATERS.
I quote:

About this item​

• Used in water heater and water tank applications to automatically allow air to enter into the piping system to prevent vacuum conditions that could siphon the water from the system and damage water heater or water tank equipment

breplum, I can appreciate this thread has spawned into a conversation about T&P valves which I hope someone finds useful in the future.
However circling back to this initially question I had is much appreciated. I have spoken to multiple plumbers, Supplyhouses and folks here on this site. After looking over the Vacuum Relief valve suggestion you sent I am shocked that out of everyone I have spoken to about this, you are the only one that has offer this up? I am curious why this is not standard on every WH and that my question to Furgisons, Supply house and this thread never came back with this as an option until now. Putting a 40$ valve to protect a 500$ WH seems like a no brainer? What am I missing? How come this is not something everyone has and uses and suggests. Is there a down side to this? Maybe these fail or do not work? Do you have any experience with these as this is exactly what I am looking for and scratching my head that no other plumbers or companies have offer this up?
Thanks for your help and circling back to this question.

 

[John Gayewski]

breplum, I can appreciate this thread has spawned into a conversation about T&P valves which I hope someone finds useful in the future.
However circling back to this initially question I had is much appreciated. I have spoken to multiple plumbers, Supplyhouses and folks here on this site. After looking over the Vacuum Relief valve suggestion you sent I am shocked that out of everyone I have spoken to about this, you are the only one that has offer this up? I am curious why this is not standard on every WH and that my question to Furgisons, Supply house and this thread never came back with this as an option until now. Putting a 40$ valve to protect a 500$ WH seems like a no brainer? What am I missing? How come this is not something everyone has and uses and suggests. Is there a down side to this? Maybe these fail or do not work? Do you have any experience with these as this is exactly what I am looking for and scratching my head that no other plumbers or companies have offer this up?
Thanks for your help and circling back to this question.

Yes they fail and do not work. That's why no one had suggested it. You'd be in the same place as using a relief valve. Relief valve$30. And actually if you re-read someone already said vacuum breakers leak often. The relief valve is a solution loaded valve. There is a spring holding it closed. Vacuum breakers really on a ball in a seat and addres held in place by line pressure which ends up being less reliable.

 

[Sylvan]

breplum, I can appreciate this thread has spawned into a conversation about T&P valves which I hope someone finds useful in the future.
However circling back to this initially question I had is much appreciated. I have spoken to multiple plumbers, Supplyhouses and folks here on this site. After looking over the Vacuum Relief valve suggestion you sent I am shocked that out of everyone I have spoken to about this, you are the only one that has offer this up? I am curious why this is not standard on every WH and that my question to Furgisons, Supply house and this thread never came back with this as an option until now. Putting a 40$ valve to protect a 500$ WH seems like a no brainer? What am I missing? How come this is not something everyone has and uses and suggests. Is there a down side to this? Maybe these fail or do not work? Do you have any experience with these as this is exactly what I am looking for and scratching my head that no other plumbers or companies have offer this up?
Thanks for your help and circling back to this question.

If the tank is HIGHER then a fixture and the faucet BELOW the tank is opened this can cause an implosion where the pressure vessel implodes

By having a device that will break the vacuum it allow air into the pressure vessel to allow drainage to happen with causing damage to the tank.

Also this type of failure also occurs in steam systems as the steam cools is causes a slight vacuum BUT a severe vacuum can implode a boiler

When I was doing low pressure boiler and unfired pressure vessel inspections the boilers on the upper floors and vessels not in the basement we had to make sure they had working vacuum breakers installed and working

Most water heaters as well as boilers are lower then any faucet so why buy a device that will never be called upon to work?

This is a video I was shown when I took a crash course on low pressure boiler inspections . Hope this will help

 

[Sylvan]

NYC has thousands of water tanks on the roof open air covers so we never have an implosion. On as fire stand pipe system one of the 27 story buildings I was in had a closed metal tank and someone decided to drain a stand pipe and the tank imploded sending 20,000 gallons of water down the elevators shafts . The vacuum relief was gagged (plugged) as it leaked and rather then replace it the handyman just placed a plug in it