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2 tank re-pipe

Hilly Member Posts: 427
I was asked to re-pipe some water heaters today because the maintenance guy couldn't isolate the tanks to flush them.

It's 2 electric 100gal tanks installed in series and they are not the same output. 1 is 32KW and the other 6KW. Those outputs might be give or take a few KW's but they're not equal.

Is there an acceptable way to pipe 2 unequal tanks properly?


    EBEBRATT-Ed Member Posts: 15,511
    If in series the first tank does most of the work assuming the thermostats are set at the same temperature, T & P and vac breakers on each tank.

    Or you can pipe them in parallel but getting equal flow can be difficult.

    Best way, put them in series and put a 3 valve bypass on each tank if they will spend the money. I would use ball valves for the inlet and bypass and a check valve on the hw outlet of each tank. Just in case somebody closes the valves and forgets to shut the power off
  • Hilly
    Hilly Member Posts: 427
    I was thinking since posting that until they upgrade and find room for both units the maybe series as is with a bypass cut in might be the simplest. My simplistic thinking tells me balancing water temperature would be the biggest issue since the tanks will recover at different rates.
    delta T