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So I had the misfortune of having to install a new water heater for my house. The old one had a slow but steadily increasing leak from the bottom of the tank and was 12+ years old. I turned off the cold water supply, opened a hot water valve at a few sinks upstairs and let it drain.

I started disassembling and noticed this:
WaterTankPlumbing.jpg

What's wrong with the order of union to shutoff? Yep, Union THEN shutoff. The only other shutoff for the house was the whole-house shutoff. If it was just me it wouldn't be a big deal, but I have 3 kids and a wife with a bladder the size of a pea (pun intended).

The other issue which wasn't a HUGE deal, but still annoying is they didn't have a shutoff on the hot water side. While I drained the plumbing, if my wife turned the water on with one of those lever faucets (kitchen sink for instance), a slow trickle would flow down.

I wound up having to turn off the whole house, cram bread up the cold spout, resolder the various bits to move the shutoff to ABOVE the union and then continue on.

I also moved from a 40 gallon to a 50 gallon tank so some rework of pipe lengths was in order.

The humor in this? After I moved the shutoff, I had my daughter hold a piece of hose up to the union to help redirect the water when I turned the house water back on (to blow out the bread) It didn't work quite that well or she didn't expect the pressure to be so severe and she got a soggy bread explosion shower! :jester: Glad I decided to turn the water on versus holding the hose! :whistling2:
 

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Think you'll find it's againt code to have a shut off on the hot side.
I would have replaced that gate valve with a ball valve while I was in there.
1/2 the time gates will not shut off completly.
Is that bladder tank on the cold side?
 

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i remember going to install a new water heater and the gas line was setup like your cold line, union before the gas valve. some people shouldn't be allowed to use tools.
 

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OK, I'll ask. Can somebody explain why this is? I have heard it several times but nobody can give me a rational explanation as to why.
Me too, another plumber in my town said the inspector made him remove his hot valve recently. When questioned, the inspector didn't have a good answer. Perhaps it is because his prior plumbing experience was residential work- mine is heavy on the commercial side where it is quite common to install both valves per the arch/eng. instructions
 

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Me too, another plumber in my town said the inspector made him remove his hot valve recently. When questioned, the inspector didn't have a good answer. Perhaps it is because his prior plumbing experience was residential work- mine is heavy on the commercial side where it is quite common to install both valves per the arch/eng. instructions
that is truly one of the dumbest things in plumbing I have ever heard off....ben sr..but thats what the inspector wants go figure..
 

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Nobody has answered what the rationale is behind not allowing a shutoff on the hot side. Can someone elaborate? because it makes no sense to me at all, and I like Logic. I also do not understand the rationale behind the expansion tank either, as they have not been required for about a hundred fifty years, and now everyone says you need one. It makes no sense, unless its because of the fear of blowing crimp fittings, like PEX. I Have a well, so I already have an expansion tank on the cold side.
 

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Thats a great way to get your daughter to trust you. Reminds me of the one my dad told me. His father (My grandfather) told him to hold a steel pin he was trying to drive into the ground while he hit it with an 8 pounder. WHAM!
Hit my dads hand dead center. He yelled at my Grandfather. My granfather said "You are crazy, I would never hold a pin for anybody" Moments of endearment.

:whistling2::whistling2::whistling2:
 

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. I also do not understand the rationale behind the expansion tank either,
The expansion tank I can understand. Some municipalities have a check valve in their water meters to prevent back lowing water into the system. This effectivly makes the system a closed one so the expansion of water when heated has no where to go. My municipality does not have that feature in their meters so any pressure build would essentialy move back to the supply source
 

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I also do not understand the rationale behind the expansion tank either, as they have not been required for about a hundred fifty years, and now everyone says you need one. It makes no sense, unless its because of the fear of blowing crimp fittings, like PEX.
Uh, no, not at all. It's because things have changed in the last 50 years. Your water line is no longer open back to the city water supply (at least the vast majority of cities.) 50 years ago when your water heater heated water, the expanded water could press back on the main city water supply. Now that route is cut off, and so you need an expansion tank. Don't need one, but your system will usually have more pressure than it was designed for.
 

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Uh, no, not at all. It's because things have changed in the last 50 years. Your water line is no longer open back to the city water supply (at least the vast majority of cities.) 50 years ago when your water heater heated water, the expanded water could press back on the main city water supply. Now that route is cut off, and so you need an expansion tank. Don't need one, but your system will usually have more pressure than it was designed for.
I agree with this, but why is the exp tank installed on the cold vs. hot?
What if the cw valve is off on the heater yet the heater is still turned on- where's the expansion going to occur? :whistling2:
 

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I agree with this, but why is the exp tank installed on the cold vs. hot?
What if the cw valve is off on the heater yet the heater is still turned on- where's the expansion going to occur? :whistling2:
I'm not sure why it goes on the cold side, but it is supposed to go between the valve and the heater, so the situation you describe can't happen.
 

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I'm not sure why it goes on the cold side, but it is supposed to go between the valve and the heater, so the situation you describe can't happen.
Yet, many peeps on here have said to put it anywhere on the cold side....
 
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