# Tank troubleshoot



## rwh (Dec 17, 2014)

Tank setup at a good friends house. I did not plumb originally. "Doesn't have as much hot water as we used to". Lower stat bad on left heater. By voltmeter. All elements good, not grounded. Included is an ISO of piping. Not sure of piping arrangement?


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## Tommy plumber (Feb 19, 2010)

Shut valves off to..... and then test. I'd start there. Maybe a component is bad. {PM me for specific components that I'm referring to}
Too many handymen may read this.


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## PLUMBER_BILL (Oct 23, 2009)

rwh said:


> Tank setup at a good friends house. I did not plumb originally. "Doesn't have as much hot water as we used to". Lower stat bad on left heater. By voltmeter. All elements good, not grounded. Included is an ISO of piping. Not sure of piping arrangement?


On your diags. By voltmeter -- does that voltmeter read ohms? What is the ohm reading on all the elements -- using the wheel I posted on the other day. Does IxR match the wattage required. On the diagram you drew, if the tank was cool the heat pump make-up would be lost in that arrangement. Does not make sense to me.


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## rwh (Dec 17, 2014)

Bill, please link or repost the wheel?


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## MDservices (May 9, 2016)

I'm not a fan of the pipe setup but that's going off of a drawing... if it used to work and now doesn't, it can't really be the piping. Careful with testing elements, don't just look for one being completely dead. Sometimes they're just half dead but you still get a resistance. That's fairly common. Definitely make sure the thermostats are set up correctly.


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## PLUMBER_BILL (Oct 23, 2009)

rwh said:


> Bill, please link or repost the wheel?


 Originally Posted by *sparky*  
_got a customer in a older mobile home,water heater goin out,3500 watt elements,he wants me to install a regular residential type 4500 watt water heater in its place,told him the wire is not big enough that feeds electric to it and it would have to upsized before i can do it,he does not believe it will make a difference,what say you gods of plumbing????.?_
time for a reprint Attached Files







OHMSLAW.DOC.doc (42.5 KB, 33 views) 
GAN and sparky like this.

__________________
*Bill Parr LMP*
*www.parrsplumbing.net*
For my alternate web site, click on ...
*A little of this and a little of that*


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## rwh (Dec 17, 2014)

Elements ohm out fine. None are grounded. Replacing bad lower stat soon. There is no check on gravity recirc. Concentric fitting from heat pump to first tank, not sure if it is correct. All near heater piping is suspect, as far as long term performance goes. What is most common sense way to pipe two tanks, gravity circ, and heat pump compensation?


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## HonestPlumb (Jan 25, 2015)

When you "twin" water heaters, they both have to be fed evenly, as well as the hot out, should be evenly distributed. In other words if your cold feed comes down to a tee, out of that tee has to be the exact same length, and configuration of piping to each heater. The same for the hot coming out, to a tee that then supplys the house with hot water.


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## Toli (Nov 7, 2015)

Check the heat pump manual. I think you'll find it's piped how the book shows.


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## HonestPlumb (Jan 25, 2015)

When the piping arraignment for a "twinned" water heater situation is not correct, the draw of hot water will tend to be uneven, sometimes severally uneven. Causing one of the two to , in this case make a control thermostat, or element to burn out . Not saying it is an absolute cause of your issue. Just the proper piping of the two water heaters to draw, and operate evenly.


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## rwh (Dec 17, 2014)

HonestPlumb said:


> When you "twin" water heaters, they both have to be fed evenly, as well as the hot out, should be evenly distributed. In other words if your cold feed comes down to a tee, out of that tee has to be the exact same length, and configuration of piping to each heater. The same for the hot coming out, to a tee that then supplys the house with hot water.


That is in parallel, I believe. This is a series setup.


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## rwh (Dec 17, 2014)

Toli said:


> Check the heat pump manual. I think you'll find it's piped how the book shows.


It shows a single tank setup? I'm looking for a two tank, gravity recirc, heat pump assist piping arrangement?


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## Toli (Nov 7, 2015)

rwh said:


> It shows a single tank setup? I'm looking for a two tank, gravity recirc, heat pump assist piping arrangement?




The two tank/ geothermal systems that I routinely see are typically piped as you show or with the supply from the get coming inthe tank at the bottom and the return coming out the top. The first tank acts as a buffer and isn't even wired for operation most of the time.

I have no idea what is the best way to pipe it. I one time I was involved in a system like yours the manufacturer was very explicit in how it was to be piped. So that's what I went with.

As for your problem- is the circ on the geothermal loop working?


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