Removing an old water heater
Water Heater Installation
Getting rid of the old
It would be a good idea to turn off the water to the house before you start to take things apart. Before you do that have everyone use the bathroom and tell them there is only one flush left for each toilet until you are finished.
If you are really lucky the cold water (blue) supply line in the water heater compartment/room will have a shut-off valve. Most won't. For a manufactured home there may be a shutoff valve under the home; either directly under the water heater compartment or near where the supply line comes out of the ground, or by the pressure tank if you are on a well.
If you have city water there is usually a shutoff valve on the house side of the water meter. These valves need a tool with a slotted end to turn. I am on a small mountain community water system and all the pipe is PVC (plastic).
The water is shut off by using the slotted tool to turn the in-ground valve, but I worry when I do it. The leverage I can apply using the tool could easily snap the valve. That would be truly unfortunate since I have no idea where the next upstream shutoff is located.
Once the water is shut off open a faucet somewhere in the house to take the pressure off the lines and let the water drain. If you can find a faucet which is lower than the top of the water heater it will reduce the amount of water that comes out when you undo the supply lines on the top of the water heater. If you uncouple the supply lines on top of the water heater that will break any vacuum so the water heater tank can drain easily.
Attach a hose to the drain valve outlet, located toward the bottom of the water heater. The shorter the hose the more easily the water will drain. Open the valve and wait while the water drains out of the tank.
This is where the "fun" started with my recent water heater install. Opening the drain line produced only a VERY small trickle of water. We applied more "muscle" and found ourselves holding the broken end of the drain valve in our hand.
We were lucky we didn't have an immediate flood. However, our extremely hard water combined with the length of time the drain had been leaking meant there was only a trickle of water coming out. That had several implications. For one thing, most of the water ran down inside the water heater and leaked out below. There was no way to catch it with a bucket. For a while I tried to soak it up with cloths, but that is very slow, and hard on the hands.
In the picture above you can see we hooked up a wet/dry vacuum which helped a lot. Unfortunately, it was leaking on the back side at the same time and running under the wall behind the water heater. It soaked the carpet on that side. If we had not had the vacuum it would have been a REALLY long afternoon.
As I got more impatient I started poking into the broken drain line with a coat hanger. My goal was to open the drain to where it was draining as fast as the vacuum could suck it up. Of course, when the ten gallon vacuum filled up I had to hold the drain shut with my thumb while my son emptied it. I was glad he had run the taps to pull cold water into the tank after we turned off the gas but before we opened the lines.