No announcement yet.

Hot Water Heater & Valves

  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Re: Hot Water Heater & Valves

    If the w.h. is in a basement, I like 2 valves. Illinois code doesn't exclude 2 valves. All commercial heaters should have 2 valves.


    • #17
      Re: Hot Water Heater & Valves

      Oh, and after the double valves,don't ferget co cap off the t+p , not!
      I can build anything You want , if you draw a picture of it , on the back of a big enough check .


      • #18
        Re: Hot Water Heater & Valves

        If you the plumber have put a ball valve on the hot you have opened the door for human nature to injure someone.

        They possibly would not want to call a plumber when the T+P is working properly and releasing water.
        They put a cap on the T+P "I can fix this honey"...
        The heater builds up excessive pressure and pinholes a weld on the tank...
        They close both valves and know it is now time to call you to replace the heater...
        You pull up to a house with a bunch of emergency vehicles in front of it because the homeowner never turned off the gas,"It wasn't what was leaking"
        With hot open maybe they will have a chance blowing a water supply.


        • #19
          Re: Hot Water Heater & Valves

          If you are on county water it is code in my state to install an expansion tank with the new water heater(cold side please!)


          • #20
            Re: Hot Water Heater & Valves

            [QUOTE=DUNBAR;185439]Follow to the end of this posting

            Given goob's asessment....let's say "goob" fires that heater back up not realizing there's an air pocket in the top 1/4 of the tank, and both valves are shut off. The upper element will fire first unless it's a completely cold tank, otherwise the bottom will fire first and the top fires to maintain ready to use hot water.

            Now in a very possible situation, the element kicks on and that air trapped in that tank is becoming heated and there's no way for it to escape. If the T&P doesn't open and expel that air....that's a pressure cooker, that's time bomb with serious ramifications if the air doesn't escape.


            Wouldn't the thermostat cut of the power to the element once it reached temperature at like 60 deg Celsius long before it would produce stream.

            I am not sure when you said about the hot water tank only being 3/4 full if the top element is in the water or not. If the element was not in the water it may heat up the air for a little but would burn out as it would get far to hot, it needs the water to keep it at a reasonably temperature.

            I thought that the pressure cooker worked on boiling water turning to steam.

            I think from memory that 1 litre water will produce 14 cubic metres of steam that's why hottie's go bang.



            • #21
              Re: Hot Water Heater & Valves

              So you have never seen a water heater thermostat fail? Happens all the time. Best plumbing practice relies on physics instead of mechanics to solve problems.


              • #22
                Re: Hot Water Heater & Valves

                Use one valve on the cold side. It's usually not alot of water to drain down on the hot side, plus you have to drain the whole water heater anyway to change it out or the element.What's another three minutes with a mini pump to drain. It is safer with one valve on the cold, just in case the T&P valve isn't working. Besides put the $12.00 dollars for the extra valve in your pocket.


                • #23
                  Re: Hot Water Heater & Valves

                  hate to say it, but i'll play devils advocate again

                  on a residential 2 heater parallel installation, installing a hot and cold on each heater is essential.

                  when 1 heater takes a dump, that heater can be isolated, and the other heater will work without the leaker leaking.

                  traditionally a 1 tank residential heater will only have a cold water valve.

                  of course, a tankless requires both a cold and hot shut off with bypass valves to allow for flushing.

                  remember that a gas heater has both a thermostat and a 1 time high limit shut off. not to mention a temperature, pressure relief valve.

                  of the millions and millions of water heater replacements done each year in the usa, how many have actually exploded that had the required relief valve properly installed?

                  remember that i'm playing devils advocate. i don't install a hot shut off on a typical single residential heater.

                  phoebe it is


                  • #24
                    Re: Hot Water Heater & Valves

                    I've walked in on water heaters blowing steam from the relief valve drain. I've replaced a lot of relief valves that are so packed with lime sediment that there was no possible way for them to function. Put the two together.

                    I never would put two valves on the water heater. Ever. That bit of convenience seems to have too much danger in the trade off.

                    And I use stainless flexes to hook up water heaters. I realize a lot of plumbers avoid them and pipe directly to the tank. Flexes may need an occasional tightening or replacement, but they make working with the heater a breeze.

                    In the aforementioned situation of multiple heaters (I only work on residential), if you're worried that the homeowner might open a faucet, just pull the flex and put on a cap or a temporary valve.

                    There will certainly be situations where the emergency cutoff will not function. And children playing in a basement will have no compunctions about turning knobs, such as gas controls or ball valves.

                    The second valve is simply not necessary.

                    (I recently repaired a water heater with the only valve on the hot side . . . go figure.)