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How to remove water from a tank water heater with clogged drain

george_42 Member Posts: 121
Turn off the supply , then remove the 3/4 hot water connection. Most heaters will now have 3/4 male fitting . Now take a 3/4 brass threaded cap and drill a hole that will just accept 1/2 pex tubing and put about a 8 ft piece of pex through it and pack the threaded part of the cap with some packing and attach to the 3/4 male fitting on the hot outlet. Push the pex down near the bottom of the heater , but not into the sediment in the bottom. Now attach an air compressor to the relief valve and put air into the tank.This will force most of the water out to a point you can handle the tank. George


  • mikeg2015
    mikeg2015 Member Posts: 1,194
    Couldn’t you jut remove the drain tube?

    Or cut the inlet pipe. The connect a hose to it and siphon from the sip tube? Outlet needs to be cut opened to vent.
  • kcopp
    kcopp Member Posts: 4,450
    I start by trying to flush water back through the drain into the tank w/ a double ended hose.
    JUGHNE Member Posts: 11,110
    If you apply air pressure to the hot pipe inlet (has connection at the very top of tank) or the pressure relief valve held open, then discharge hose to the cold pipe connection (has dip tube near the bottom of the tank) ,
    the air will push the water out unless the dip tube has holes in the upper portion to break a vacuum.

    Or if there is a floor drain right there with correctly sloped floor, you could just drill a hole in the tank and let it drain.
  • SuperTech
    SuperTech Member Posts: 2,205
    edited February 2019
    I'd try a CO2 cartridge and my oil line blow out gun or my Gallo gun first. If you are changing our the tank I'd consider drilling a hole and letting it rip, depending on the basement and floor drains or sump pumps.