On the off chance that "Chris, yes..." meant to write what I
learned. Read everything before doing anything.
Tools: Pipe wrench, torch, flux, solder (no lead, please),
finger, Rectorseal #5, pipe cutter.
Parts: Dip tube, copper union.
* Shut off the water to the WH! Usually a faucet on the cold
Turn down the heat (usually clockwise) so the burner
doesn't kick on while you're working.
* About half way between the shut off valve and the top of
the WH, cut the tubing. Use some copper wire, to hang the
water supply tube up a little, so it doesn't get in your
Use the pipe wrench, to turn the big nut where the cold
supply comes into the top of the WH. That should break the
old Rectorseal, and the length of copper tubing threads out.
* stick finger in the hole, and see if the old dip tube is
still there. It probably is not.
Slip the new dip tube in. If you don't have a lot of head
room, don't worry. You can angle the tube in, and straighten
it later. I've put dip tube in application with not much
* Cut about 3/4 of an inch of tubing off either the stub you
just cranked out, or the pipe hanging down.
* Lay the pipe stub horizontal, on something fireproof like
a brick. Sand, wire brush, flux, and solder half the copper
union onto the pipe stub. Yes, you can put it back on the WH
and solder it there. But soldering uphill is a PIA.
Paint the exterior threads of the pipe stub with
Rectorseal, and thread it back into the top of the WH. Crank
it down, snug but not tight.
* Shake the cold supply tube to dry it out. Wire brush,
sand, flux, the other half of the union and the tubing. Be
sure to slip the big nut on first, and use some copper wire
to keep it out of your way.
Release the tubing that's held up by copper, and rest the
two parts of the union together. Torch, sweat, and solder
* Some plumbers teach to Rectorseal the mating surfaces of
unions, and also the threads. Can't hurt. Use two pipe
wrenches to tighten the union. Cross brace the union so you
put the turning torque only on the fitting.
Say a prayer to the gods of plumbing, and then turn on the
cold water supply. VERY little bit, and wait for it to come
up to pressure. Wait a while, and see if it looks like it's
You just saved $325 in labor charges from a plumber, and you
get to keep the tools. A copper union costs 3 bucks, a sweat
coupler costs 30 cents. But, the next time you work on the
WH, you can change the dip tube with just wrenches and
Christopher A. Young
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