i need to replace the dip tube on the water heater. there is no cold water shutoff on the heater itself, does it matter where i shut off the cold?i have two copper tubes going into the top of the heater,the hot has some kind of filter or something connected to it [ brand name therm-x-trol] and it has a shutoff on that line. also you said to turn on the hot to relieve pressure,do i leave it on while i replacing the tube? sorry, but i'm pretty much a bone head when it comes to this stuff. thanks for your help!

ballengerb1

Shut off you water main and the fuel to your heater. Open a faucet somewhere to blow off pressure. I would also open and drain down the heater itself a few inches, use the drain cock near the floor. Tell us what the fittings look like on the top of yout tank, are they soldered or dielectric fittings or what?