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Comment on First time ever installing a water heater, or doing any plumbing...

An expansion tank is necessary for water heaters, because the process of heating water causes it to expand. Without a reserve tank, pressure could build to unsafe levels

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SpeakinTelnet@sh.itjust.works ⁨1⁩ ⁨year⁩ ago
All tanks are equipped with a safety release for the pressure and the only time when that delta in pressure can be problematic is when you go from completely cold to hot due to the higher amount of water that can fit in the tank at lower temp.

Otherwise I’ve never seen a house in Canada with an extension tank attached to the water heater and the water come in ice cold in the winter.

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falsem@kbin.social ⁨1⁩ ⁨year⁩ ago
Pressure won't build up, it will be let out by the pressure relief valve and make a mess on the floor. Which is also undesirable.

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- SheeEttin@lemmy.world ⁨1⁩ ⁨year⁩ ago
  Well, right up until the pressure relief valve fails. Whether it fails open or closed, you’re gonna have a bad time, because either way you’re probably going to have a lot of water where there’s not supposed to be water.
  
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AnotherPerson@lemmy.world ⁨1⁩ ⁨year⁩ ago
If it’s necessary then how did my last tank make it 20 years without one?

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- Rixonomic@lemmy.world ⁨3⁩ ⁨weeks⁩ ago
  The expansion tank isn’t just for the water heater. That increased pressure puts undue strain on the entire plumbing system in your home. It will cause toilet fill valves to fail, supply lines to rupture, and possibly even pinhole leaks. A lot of plumbing issues are solved by installing an expansion tank.
  
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- rockSlayer@lemmy.world ⁨1⁩ ⁨year⁩ ago
  Honestly, I don’t know, I’m not a plumber. There are a couple possibilities, including that it was built into the water heater or the relief valve did it’s thing. Some water heaters don’t need expansion tanks at all, either. It’s generally a “just in case” thing, since the right failures in the wrong way could lead to a hot water bomb going off in your house.
  
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  - AnotherPerson@lemmy.world ⁨1⁩ ⁨year⁩ ago
    Yeah but that was like the coolest mythbusters episode ever /s
    
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AnotherPerson@lemmy.world ⁨1⁩ ⁨year⁩ ago
In reading it looks like it is for homes newer than 1986? Our old water heater was 20 years old and we never had any issues with the pressure getting to high.

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