Shutoff Valve in Hot Water Line of Water Heater

Discussion in 'Water Heater Forum, Tanks' started by aaronm, Dec 14, 2008.

  1. Probedude

    Probedude New Member

    Messages:
    137
    Location:
    CA
    You're right about the rise in boiling point - I completely overlooked that.

    Still though there are 3 safety mechanisms that have to fail

    - high temp cutoff not working
    - thermostat not working
    - TPV not working

    So all these failed in your example apparently. I can see the point of not having a shutoff on the output of the WH, but if all three safety mechanisms fail I would say that this would be a big problem in MOST installations regardless.
  2. SewerRatz

    SewerRatz Illinois Licensed Plumber

    Messages:
    1,706
    Location:
    Chicago, IL
    Ahh found my Chicago code book. Dang brother-inlaw had it.

    From the 07 Chicago plumbing code:
    18-29-503.1.1 Shut-off valves Shutoff valves for water heaters or heated water storage tanks may be installed on the inlet side only.
  3. Homeowneress

    Homeowneress New Member

    Messages:
    1
    Location:
    dana point, CA
    I am an example of someone who shut off the hot water valve and the main

    Ian Gills, "Robin Hood", thank God you posted on here in rebuttal and got the debate going and then cleared up....thanks to SewerRatz expertise and further input.

    I noticed water on my garage floor and traced it back to a drip leak at a section right near the hot water shut off valve. My husband and I were leaving for a cruise that early morning and had no time to call the plumber. Touching the drip it was hot water, and I concluded it would stop if I shut off the hot water valve, which it did. I then went outside and turned off the main and we left for a 10 day cruise. I had no idea this was a potential killer bomb. Now I know. Hope others will chance upon this thread and learn the danger involved in the simple act of shutting off a shut off valve. Wow, I get sicked thinking about what I could have caused. The gas company should really send out stickers to be placed next to any water heater hot water shut-off valve to each and every home, that says "do not shut off this hot water shut-off valve for more than 30 minutes - explosion danger!!".

    Thank you Ian Gillis, "Robin Hood", and SewerRatz!!!!!!!! Your posts may save lives.
  4. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Like I have been saying for years, you need REDUNDENCY- back up to the single stupid relief valve.

    And guess what boys, its made, and no one uses it because granpa didnt have one.

    http://media.wattswater.com/es-BRV.pdf

    http://www.watts.com/pages/_products_details.asp?pid=564

    Anyone ever heard of a tee with a secondary, plain pressure relief valve on the heater also? Is 12 bucks too much to save a house or heater? Got a car without an emergency brake lately?

    It was too expensive for for the Japanese at their sieve of a nuclear plant, and now have a look at what their lack of forethought caused. -30 kilometer circle of new wilderness, and fish that glow in the dark.

    Funny how they floated their department stores on huge springs. Built the reactors rock solid. I guess the Prada purses are more important that a few hundred thousand houses being abandoned.
    Last edited: May 18, 2011
  5. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Oh Boy...

    Here we go again...

    http://www.watts.com/pages/_products_details.asp?pid=852

    I'll keep using the Park and the supplied emergency brake...

    I'll Pass on carrying and using a wheel chock...
    Last edited: May 19, 2011
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,896
    Location:
    New England
    Actually, the new car I just bought uses a computer driven hydraulic system for the parking brake...there is no direct mechanical lever or pedal to mechanically operate the brakes. If the engine is running, it works on all 4 wheels, if it's not, it only works on the rear wheels. You pull the little switch up to activate, and push it down to turn it off.

    As we've gone over multiple times, the code approved method is an expansion tank along with the factory T&P valve. If doing more makes you feel better, go for it, but millions of people don't do more and their tanks haven't blown up, nor do I expect that they will.
  7. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Wheel chocks are required by law in many places for trucks because they are mechanisms in PLAIN SIGHT that do not fail.

    And all my tractors and excavators have hydraulic acculumulators, seem to NEVER break or leak, and within a few seconds lock up all drive mechanisms when the engine is killed. As soon as you turn off a 100,000 pound excavator, you have nothing to do but go home, no levers to pull. Great system.

    Very handy on the edge of a cliff when the engine dies and braking power ends. Might not work so well on a pickup at 80 MPH on the freeway.

    A hydraulic accumulator on autos, with brains, would be a huge safety factor for braking and parking.

    Funny how a backup relief valve disturbs everyone. But all those stupid backflow valves that we lived without for 150 years are gods new standard without question. How many of you got sick from reverse flow water? Better to regulate chickens in the market for bacteria.
    Last edited: May 19, 2011
  8. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Because you propose it instead of a thermal expansion tank which is about the equivalent of us saying strip the brakes off your truck because they might fail and use "Fail Safe Wheel Chocks" instead....

    The fact is your relief valves can and do fail quite often and plumbed to a drain and in a failed or, operational state could conceivably run full flow unnoticed until a well goes dry or, you have a heart attack when you open your water bill.

    So jump off your engineer soap box and realize the data and logic you are applying to your brilliant solution is flawed badly.

    That is why we repeat ourselves every time you mention this....

    We will repeat it as often as you do, because bad advice does need to be exposed as such.
    Last edited: May 19, 2011
  9. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Sure expansion tanks help, when NEEDED, but they have the same pressure rating as the heater body, so blowing the internal bag is not back up like another pressure valve. You can do another myth busters video with a expansion tank in the circuit, and the simple question is which one blows first.

    Unless you have 2 shut off valves on the water heater and a absent relief valve, the value of the exploding water heater videos is the same as a video showing what happens when you build your charcoal barbeque fire right under the gas tank of your motor home.
  10. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Okay... Let me get this straight now...

    If someone turns off the two valves on the inlet and outlet of the water heater... (Even though us plumbers don't put one on the outlet)

    and...

    If the T&P Valve fails..... which is easily tested and should be regularly.....

    and...

    If the Thermostat fails in a manner which causes heating continuously 50-50 chance....

    and....

    If the TCO (Thermal Cut Off) fails....

    Oh Boy Mr Engineer... Just how much redundancy do you want anyway?

    By your theory we've got your dump truck parked:

    The emergency brake is set...

    and

    The engine is off and in lowest gear...

    and

    the wheel chocks are in place

    and

    the truck is on level ground....

    All we can do now is take your silly azz little ball valve and throw it at the window breaking it....

    Come on Ball valve grow some grey matter will ya?
  11. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Everyone must be bored around here.

    My point was that the exploding water heater videos are fun, but almost irrelevant. As you well point out with all the other devices to be bypassed.

    Leave out the hot shut off, and now you have lots of pipes and hoses that can become your pressure relief valve.

    As to grey matter, dump trucks do not have nitrogen filled liquid hydraulic accumulators for the e-brake. And the dump truck driver with the most of it actually uses his wheel chocks.

    In case you missed the POINT - expansion tanks provide no help with a run-away [tampered with] water heater.
  12. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    No, We are just tired of you the "Unknowing" spewing your lack of wisdom on this subject and determined to rebut the bad advice you consistently spew...

    We have tried to educate you on the subject but due to a lack of absorbency your grey matter repels knowledge...

    This is a common occurrence in some people in your chosen field. Most continue to educate themselves all through life and become very good in the field. Others blindly decide at some point that they know everything and at that point cease to have any value.

    And your ball valve with a relief does?

    If you will note at the product link you provided it states...

    "It is for applications that require a means to shut off the water supply to the water heater and for providing protection from excess water pressure caused by thermal expansion."

    Your assumption that it provides protection with a runaway water heater is completely out to lunch.

    A properly sized T&P Valve will provide that protection. In looking at the specifications for the Watts 100XL T&P Valve you will not the following lines of information that do not appear on the product you recommend...

    A.S.M.E Rated*, CSA Listed. Self-closing T&P Relief Valves
    for Water Heaters up to 105,000 BTU/Hr.
    The combined 2 in 1 T&P relief valve provides the least expensive and proven means for protection against both excessive
    temperature and pressure emergency conditions.
    Provides fully automatic temperature and pressure relief protection for hot water storage tanks and heaters up to 105,000 BTU/HR.

    Each water heater and hot water storage tank shall be
    equipped with a CSA and A.S.M.E. Rated* automatic temperature and pressure relief valve to protect the heater from excessive pressure and temperature. The device shall be ANSI Z21.22 certified. The BTU discharge capacity of the device
    shall be in excess of the BTU input rating of the heater.


    Now I'm not a General Engineering Contractor so I don't profess too have knowledge about digging irrigation ditches, land leveling, installing driveways, and ditch digging... Frankly I don't want that knowledge... I'll bow to your excellence or, hire some undocumented day laborers to do the work...

    I'm a plumber! That is my area of expertise...
    The engineers at Watts are a slightly different type of engineer than you are...
    They have expertise in the safety controls needed on a water heater. So me the plumber having an awareness that you lack have decided that...

    I will have a safety device that is CSA and A.S.M.E. Rated, ANSI Z21.22 certified, With a BTU discharge capacity in excess of the BTU input rating of the heater...

    Now go dig a ditch or, something....
  13. redwoodvotesoften1

    redwoodvotesoften1 New Member

    Messages:
    78
    Hot Dang Redwood!
    Wat is it wit alla these engineeers that wanna think they knows mor bout plummin than Redwood.
    They seems ta have no end to the line of em comin ta git ther noze bleedin.
  14. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    The unknowing with repellant soft grey matter dont know the meaning of redundency and rely on granpas valves rather than the new choices in conjunction with the valve that comes installed on the heater.

    Must be bored not having Ian to kick around lately. Glad to be of service.
  15. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    You give yourself way more credit than you are due...
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